DPF error codes part 2

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DPF error codes

In the previous article, we described what diagnostic trouble codes (DTCs) are. You could read there also how they work, and how to use them to diagnose the exhaust system. Here we will present the most common examples of DPF error codes related to sensor faults. In the second part, you can read the error codes related to other failures.

Error codes can be divided into “soft” and “hard”. Soft codes react to the current state of the car and if it changes, they automatically disappear. Hard codes indicate a problem until they are repaired and manually canceled using a scanner.

P0470 – Flue gas pressure sensor fault / P0471 – Flue gas pressure sensor range / performance fault

When the pressure in the intake manifold does not match the value transmitted by the exhaust pressure sensor, error P0470 or P0471 is shown. The value can also be compared to the air pressure around when the key is in the ignition.

The reason can be related to the electrical circuit or the breakdown of the exhaust pressure sensor itself. In very rare cases, the powertrain control module (PCM) may fail.

Much more often the causes are mechanical. The pipe between the exhaust manifold and the pressure sensor has been clogged or has leaked from the exhaust gas recirculation (ERG) system, e.g. with a leaking valve. Also, the air inlet or charge air inlet could leak.

Ignoring the cause of the error code may in turn result in clogging the DPF filter and the P242F code.

P2002 – DPF Performance Below Threshold (Bank 1) / P2003 – DPF Performance Below Threshold (Bank 2)

There are pressure sensors on both ends of the DPF filter. Deviations from the norm will be marked with error P2002 or P2003. They indicate that the filter is clogged and are also signaled on the dashboard. They are one of the soft codes. After successful self-regeneration of the filter and pressure return to normal, they disappear.

The cause is usually a clogged or damaged filter. Fuel with a high sulfur content or non-C or LowAsh engine oil increases the amount of carbon deposits, sediments and ashes, and thus clogs the filter and hinders its self-regeneration. Another reason for displaying the code is an air leak that changes pressure and sensor readings. Most often these codes appear when the car is not able to self-regenerate through urban driving style and driving short distances.

Ignoring the code may result in completely clogging the DPF and reducing the exhaust system performance.

DPF error codes

Flue gas temperature sensor circuits 1st order sensor 2 (P2031, P2032, P2033) and 2nd order sensor 2 (P2034, P2035, P2036)

The exhaust gas temperature sensor (EGT) is fitted on most cars. Its task is to monitor and regulate exhaust gas temperature. Thanks to this, the DPF does not get too hot air (it could damage it) or too cold (it would prevent automatic regeneration).

The sensor can cause an error due to its own defect or mechanical damage to the parts of the exhaust system in its vicinity – loose connectors, terminals, their corrosion, cable damage or lack of insulation. No reaction from the mechanic side on these errors can be costly. DPF clogs without self- regeneration or damages when overheated.

P2452 – DPF a Pressure Sensor Circuit A / P2453 – Range / Performance of the DPF Pressure Sensor Circuit Range

On some cars, the pressure sensor is installed in the engine compartment, not the DPF. Hence, the measurement is made at a distance from the filter. The device itself is referred to as sensor A. Similar to the traditional construction of the exhaust system, pressure deviations from the manufacturer’s standards are signaled by an error code and lighting of the control lamp.

Some of the reasons for these codes are also similar – damage to the sensor or electrical circuit, clogged sensor cables, inefficient self-regeneration or filter clogging. A different location also gives some other ideas for diagnosis. The exhaust fluid tank is empty or flooded with bad fluid. When replacing the filter, the code may indicate the incorrect connection of a new element.

P2454 – DPF A pressure sensor circuit low / P2455 – DPF A pressure sensor circuit high

The pressure sensor A may be damaged while the DPF is operating normally. Then it will show too low result. Usually, the failure is related to a broken cable or broken electrical circuit, e.g. a short circuit or an interruption. However, you must also take into account the possibility of exhaust gas leakage.

However, be careful with code P2455 as it may damage the exhaust system or engine. Too high pressure readings can have the same causes as for code P2454. But, in addition, you must take into account the possibility of:

  • damage to the DPF,
  • lack of self-regeneration,
  • empty exhaust fluid tank
  • or its wrong mixture.

See also the third part of article with codes P242F, P2463, P244A and B, P2458, P2459.

DPF error codes

Categories:
DPF error codes

An ordinary car user with a DPF filter will never have to deal with DPF error codes. A mechanic is different matter. For him, diagnostic trouble codes (DTCs) are a mine of knowledge, what is wrong with the car or its subassemblies. When internal sensors detect an abnormality or deviation from the norm, they transmit the code to the on-board computer diagnostic system (OBD).

Types of DTC error codes

Everything in the world tends to standardize. The international standards SAE and ISO have been in force since 2000 for car manufacturers, which unify OBD codes (the European version is EOBD). Therefore, the mechanic, independent of the manufacturer or the vintage, knows immediately what the defect is about.

Each code consists of five characters. The first letter symbolizes the location of the failure, the first digit says whether it is a generic fault or manufacturer fault.

Sample letters:

  • B – body

  • C – chassis

  • P – engine

  • U – communication system

 

The next three digits are responsible for the location in a particular car system and the type of error. For example in code P:

  • 0, 1 and 2: for the air/fuel mixture

  • 3 : for the ignition system

  • 4 : for checking auxiliary emissions

  • 5 : for engine idling

  • 6 : for the onboard computer and ancillary outputs

  • 7, 8 and 9: for the transmission (gearbox)

  • A, B and C : for hybrid propulsion

 

Is the DTC error code a full diagnosis?

 The DTC error codes is just the beginning of the diagnosis. It should be verified with the vehicle’s operating instructions, because some codes (P1) are sometimes specific to the manufacturer.

 When the diagnostic system indicates a component failure, check several components. The sensor itself, which sends false data or its cabling, could have been damaged. When the sensor is functional, it is necessary to see the whole sequence of the system. It is possible that a part has been broken which affects further elements and the DTC error code applies to the latter. For example, a dirty air flow sensor affects fuel-trim adjustments. In this situation, the air sensor will indicate problems with the fuel mixture.

DPF error codes

Also, each of DPF error codes can have many causes and therefore each case must be considered individually.

We have included specific codes in a separate article. There is no one, top-down and always working procedure. The repair is based more on the mechanics’ experience and diligence. A entire exhaust system is quite complicated and it is not always possible to clearly indicate what and why it failed.

The first step should be to look through technical service bulletins (TSBs) for a specific car model. Certain errors are popular and manufacturers make commonly available corrections. This will help you save time when diagnosing.

If this does not help, look at the exhaust system thoroughly, not just the DPF filter itself.

DPF error codes

DPF error codes are the first step in diagnosis

The filter can be functional and other element is not worked properly eg:

 If the fault still can not be found, it is worth taking a closer look at the engine oil and the fuel used. Their poor quality can also affect the operation of the DPF filter and cause an error to be sent.

Broken DPF filter

The list of things you need to look at is long. If you are sure that the filter itself is not working as it should, better check:

  • pressure and temperature sensors, their circuits – they can be easily replaced for verification

  • sensor ports and their tubes can be clogged – replaced

  • system circuits – if you rule out sensors and wires, check the circuits. Disconnect all associated modules before testing. Check the continuity of the circuit with a voltmeter, if necessary, replace the circuit.

  • clogged DPF filter – then a replacement or professional cleaning is recommended

  • defective DPF filter – often unprofessional filter cleaning may cause damage to the ceramic interior, so beware of it

How to proceed to prevent clogging of the DPF filter?

The driver who has already had a clogged DPF filter at least once knows exactly how to proceed in order to avoid repeating this situation too quickly. However, it is worth following a few general rules in every car.

Unburnt combustion products are deposited in the DPF filter. Therefore, the better the quality of diesel or gasoline, the better it burns and leaves less soot and carbon deposits. Thus, less of them settle in the filter and easier to burn them while driving. The bad habit is also to wait for a visit to the gas station. Some cars do not turn on automatic regeneration if there are less than 10 liters of fuel in the tank.

Another element that you need to take care of is engine oil. It must be in good quality, then it absorbs a lot of soot. In addition, it should be dedicated to vehicles with DPF filter, i.e. low ash content, e.g. LowSASP or Class C in ACEA classification. You can read more about DPF engine oils in this article. In addition to high quality, it should be replaced regularly. Oil that has been in operation for more than a year or on which the car has traveled more kilometers than the manufacturer’s recommendations loses its properties. Instead of helping, it will start to hurt.

The DPF is automatically regenerated during longer driving. It will not prevent the filter from being repaired, but it will generally delay the need for replacement. To start it, it is enough to drive about 15-20 minutes at speeds above 60 km / h once every 3-4 weeks or 300-600 km, with a minimum engine speed of 2000 rpm.

Damaged lambda sensor – symptoms

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Damaged lambda sensor - symptoms

When it was first used for general use, it was the nineties of the twentieth century. At that time, the world began to pay more attention to the environment, and thus to the quality and quantity of car exhaust. The lambda probe was supposed to be a solution to solve the problem. The innovative solution was a source of pride for producers. Especially who emphasized their pro-ecological approach by placing appropriate markings on cars, indicating the presence of a probe. For car users, all this sounded very mysterious, modern and attracted attention. What is this? What is its operation and why it fails from time to time? Damaged lambda sensor – do you know all the symptoms?

A bit of history, or how it started?

A specific solution was created in 1979. However, widespread use took place only in the nineties of the twentieth century. In the initial period, the lambda probe was used only in gasoline engines. Today it has changed. Due to extremely restrictive combustion standards, several probes are used in diesel and also diesel engines.

What lambda sensor is it and what is it for?

It is an electric sensor that is located in the exhaust system, and more specifically in the exhaust pipe in front of the catalytic converter. The task of the probe is to measure the composition of exhaust gases that come out of the engine compartment.


Internal combustion engines require a mixture of air and fuel that, in simple terms, “explodes” in the engine compartment and contributes to driving the vehicle. The purpose of the probes is also to monitor the amount of air that has not been consumed in the exhaust gases emitted from the engine. The collected information is transferred to the control computer. It on this basis selects the correct composition of the fuel-air mixture.

There should be a mixture in the engine compartment characterized by a strictly calculated ratio, which is 1 (fuel): 14.7 (air). Such a ratio ensures optimal combustion of fuel and, consequently, proper engine operation. It also reduces the amount of harmful substances that enter the atmosphere, including exhaust gases. Incorrectly selected mixture not only affects the quality of exhaust gases, but also can cause engine failure.

Why is the lambda sensor failing?

Damage to a particular device occurs under extreme conditions. Due to the fact that it is located in the middle of the exhaust system, as well as the exhaust system, it is affected by very high temperatures exceeding 300 degrees Celsius. What’s more, such elements as water, road salt, dust that escape from the outside also have an unfavourable effect. According to estimates, the probe is able to survive mostly on a mileage of about 50-100 thousand kilometres. However, the good condition of the engine and the refuelling of high quality fuel can contribute to a significant extension of the life of the device. 

Symptoms of damaged lambda sensor

Among the symptoms informing about the damage of the probe, the increase of combustion, which may even exceed 50%, is mentioned first. Another symptom that can be felt by the driver is uneven engine operation. Damaged lambda sensor can be indicated by a red indicator light, which is activated on the dashboard of the car. Sometimes the failure of the device can be assessed on the basis of a coloured film appearing on the probe. The colour observed may indicate the likely cause of the abnormality. And so when we notice the colour:

    • red – we can suspect the presence of harmful elements in the fuel,

    • dark brown – then we get information about too rich air-fuel mixture,

    • green – we know about the leakage of refrigerant fluid,

    • black and greasy – we are alerted to excessive oil consumption.

Damage to the lambda probe can also be caused by irregularities in mechanical failure of its structure. For example, fusion of cables, bending, corrosion of styles or loosening of gaskets.

Repair of damaged lambda sensor

The repair should be carried out by a mechanic. In modern cars, access to the lambda probe may not be easy. In order to disassemble and replace a damaged device, many elements must be used. An important issue is also the removal of control computer errors. This can not be done without a specialized device.

A malfunctioning probe can not be ignored. Failure to take corrective action may involve high costs. It contributes to greater combustion, which is particularly severe when moving around the city. Failure to repair can also damage the particle filter. That is why it is so important not to ignore any symptoms that indicate a lambda probe failure.

Engine exhaust systems part 2 – silencers

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Der Auspufftopf tłumik środkowy middle muffler middle silencer

One of the elements of the exhaust system is the silencer. It plays a very important role in the entire exhaust gas extraction process. Engine exhaust systems would not function well without this element. Therefore, to choose the appropriate silencer, which will meet all the standards in the form of appropriate sound intensity or engine performance parameters, please familiarize yourself with its specification. This knowledge will not only be useful for car repair shops that will be able to choose the right silencers.

Engine exhaust systems – construction types of silencers

Two types of muffler designs can be distinguished: the first one is the silencer roll construction. The housing has a round or oval cross-section. A silencer is rolled up and then joined along by rolling the formed overlap. The previously prepared elements are placed inside the silencer and the covers closing the ends of the casing are connected. Pipes are inserted through covers that are part of the silencer centre. They are welded to the housing covers.

The second one is a type of two-bay structure, which is more modern technology. It allows a better fitting of the muffler housing to the car floor plate, thanks to which the air flow resistance is lower. Two-bay dampers consist of two parts of the casing, made by stamping from a cut sheet or a steel strip. In the middle of one of them, baffles and perforated ducts are installed, which lead the exhaust gases. Due to the multi-stage process of creating this type of silencers, it is necessary to use many tools.

Silencers available on the domestic market should meet certain standards: UNECE 59 and local regulations.

Types of exhaust silencers that have the function of reducing noise

Absorption silencer

In absorption silencer the exhaust flows only through the perforated pipe and through the special openings have contact with the space. Filling with special damping wadding, which is made of steel wool or mineral glass wool. It impedes sudden increases and decreases in pressure due to its surface and inelasticity, which in turn suppresses the movement of particles and contributes to the release of heat. The absorption silencer suppresses sounds above 500 Hz. Its damping capabilities increase until the sounds reach frequencies above the value of 2500 Hz.

Reflective silencer

The silencer works on the principle of multiple reflections of the sound wave that moves with the exhaust. Losing some of the energy during rebound causes the wave attenuation. It is necessary to set several cross-sectional changes in order to make the effect optimal. This setting will cause a resonance phenomenon, i.e. the frequency of vibrations will coincide with the frequency of natural vibrations in the chamber, where the waves move. There are two types of reflective silencers:

  • series resonator – resonant phenomena occur in the main exhaust line,
  • bypass resonator – the phenomena occur in the branch pipe from the main duct, which leads the fumes.

Interference silencer

During a meeting of two or more vibrations, they overlap, which can be strengthened or extinguished. The vibrating stream of exhaust gases is divided into two streams. One moves with a shorter channel, the other one with a longer one. When the two streams meet, there is interference in the form of blanking.

Combined muffler

None of the previously mentioned silencers, suppresses sounds on all frequencies. That is why the created silencers have several methods of damping vibrations.

Engine exhaust systems part 2 – silencers

Engine exhaust systems – silencer damages

The silencer is not immortal or indestructible. Both inside and outside can be damaged by corrosion. Corrosion from the inside is caused by chemical condensate, which is acidic, mainly consisting of solutions of sulfuric acids, nitrous hydrochloric acid and their salts. In absorption silencers, the absorption mat absorbs condensate. In reflective and combined silencers, the condensate drops on the internal ducts of the silencer. Moving the car over unevenness, also affects the load of the muffler. Therefore, the type of steel that directly comes into contact with the condensate determines the lifetime of the silencer. The best choice will be stainless steel sheet or sheet coated with aluminium.

Remarks – assembly of the outlet system

  1. Even the smallest leak in the exhaust system affects the engine’s operation. All the more when it is near the engine. In case the car is equipped with a catalytic converter and oxygen sensor, leakage contributes to serious consequences, including: the catalyst is unable to remove toxic nitrogen oxides.
  2. The ingress of air prevents proper exhaust gas analysis.
  3. We treat sealing pastes as temporary repair of leakage.
  4. Before painting the outlet systems, the surface should be cleaned and degreased. Use only heat-resisting paints that can withstand temperatures of 800 degrees Celsius and more.
  5. Spare parts should be mounted using hose clamps. They should be properly mounted and selected.
  6. For better tightness of pipe connections, it is recommended to use a sealing paste.
  7. The system heats up during operation due to high temperature and can be extended up to 20 mm. When mounting and suspending the exhaust system, the rear muffler must be moved by this amount so that the pipe end does not hit the vehicle body.

Engine exhaust systems – how it works?

Categories:
Engine exhaust systems

The exhaust system is a very important element that plays an important role in motor vehicles. Therefore, the engine exhaust systems must be properly adjusted so that the car or other vehicle does not get prematurely broken. It is worth getting acquainted with the basic information on this topic. This will facilitate understanding, and can even help in the event of irregularities associated with the exhaust system.

Engine exhaust systems – exhaust gases

The exhaust gas is a mixture of gases and solid particles. Solids include those that are not in gas form. Water is also part of the exhaust, because it is its product and most often occurs in the form of steam. Exhaust gases get out of the exhaust systems, which are converted into energy in the process of air-fuel combustion of the resident.

Energies can be divided into three parts. The first one is in the form of vehicle propulsion. The second one is used in the cooling system and the third one escapes with the exhaust gases. In the last two cases, it is mostly lost.

Therefore, energy is noticeable under several forms:

• exhaust temperature;
• hypertension, which is a measure of potential energy;
• the speed of the tide, which in turn is associated with kinetic energy
• vibrations of the exhaust column.

engine exhaust systems consist of many elements

Engine exhaust systems consist of many elements

Engine exhaust systems – tasks and features

The main task of the exhaust system is to discharge exhaust gases from the vehicle into the atmosphere. Second task is reduce the noise that occurs during this process. In addition, it should purify the exhaust to such an extent that the harmful components do not exceed the permissible standard specified in the regulations.

In terms of features, the outlet system should be characterized by:

• the most efficient engine operation, which is read in the full range of loads,
• flow resistance should be minimal, so that the maximum engine power will not be a problem,
• minimal heat radiation affecting the correct exhaust temperature,
• lifetime in accordance with its guidelines,
• materials that are used for production can be re-processed without any problems
• low costs.

When the exhaust system is optimally operated, you can increase the engine power and even reduce fuel consumption. The quality of the outlet system is evidenced by a slightly larger residual amount of exhaust gas in the combustion chambers. It is produced during small and medium engine loads (internal recirculation). In the case of heavy engine loads, as much as possible exhaust gases should be removed.  Then you can enter the largest amount of mixture into them. That is why regular check on exhaust parts is so important.

The catalytic converter’s task

The catalytic converter is designed to reduce the amount of harmful substances contained in the exhaust. In addition, it suppresses the vibrations of the exhaust, which affects the lower volume of the engine. To ensure sealed connections of the exhaust elements, appropriate exhaust gaskets, exhaust rings, sealing cement paste for the elements of the exhaust system are used.

Water is also one of the exhaust components. Water vapour arises when the flue gas has a high temperature. Unfortunately, the farther away from the engine the temperature is lower, which can cause water to condense. It occurs when the temperature of the outlet element is lower or the same as the temperature that causes the steam to condense. In the exhaust it is 50 degrees Celsius. This can occur in all components that are cooler and the final silencers are most susceptible. The condensed liquid is not water because it contains other substances – it is called condensate. Most of it is produced during urban rides on small sections. The exhaust gases are unable to heat up the exhaust system properly.

Counteracting in the formation of condensate and exhaust back pressure

The basic action is to ensure uniform heating of all elements of the exhaust system. Unfortunately, while the engine is cold, the exhaust temperature is too low to prevent condensation.

It will be helpful to use a special construction of the silencer. It will suck up the condensate from its interior. Helpful means are also those that will limit heat emissions from the exhaust system to the outside. The reduction of thermal energy losses is also possible using properly welded elements.

Differential pressures cause the exhaust to flow because the pressure in the combustion chamber is different from atmospheric pressure. It is necessary to obtain an identical flue gas flow rate and to overcome the flow resistance that occurs during combustion. The differential pressure measured between the inlet and outlet of the silencer or the entire exhaust system for the engine operating at full speed is the resistance of the exhaust flow and is called as back pressure. The exhaust back pressure for a typical exhaust system with a catalytic converter. It should be 30 to 40 kPa, and a typical silencer has a back pressure of 10 kPa.

Emission standards in the EU

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Emission standards in the EU

In recent years, much is said about air pollution, and the fight with them is at its best. The European Union has set itself the aim of improving the state of the environment by introducing regulations regarding the control of admitted vehicles for sale. The emission standards in individual countries are subject to ever more restrictive regulations. What are the current regulations in the emission standards in the EU? And what can be introduced in the future? It’s worth taking a look at the rules in force. In the result you do not become a victim of a smog alert.

What is the euro standards about?

Euro 1, 2, 3

European emission standards is the norm, which applies to limit emissions from cars in the European Union. Solid particles, nitrogen oxides, sulfur oxides, carbon dioxide – all this is covered by the concept of exhaust emissions. Their maximum amount was set with the introduction of the Euro 1 standard in 1992. Two more standards, namely the Euro 2 and the Euro 3, did not make such a big confusion among the producers. Although they could have made it clear that in the future we will need to look at particulate matter more closely. They only showed that cars with a gasoline engine can have more carbon dioxide emissions, while vehicles with a diesel engine have nitric oxide.

Euro 4

The Euro 4 standard, in force since 2006, has started a real revolution. Carbon dioxide in gasoline vehicles was reduced by more than half – from 2.3 g / km to 1 g / km, and in Diesel engines from 0.64 g / km to 0.5g / km. Thus, nitrogen oxides changed, from 0.15g / km to 0.08g / km in gasoline and from 0.5g / km to 0.25g / km in Diesel.

Euro 5 and 6

Another norm – Euro 5, in force since 2011, did not bring any major corrections. Carbon dioxide remained at the same level in gasoline and diesel engines. It is slightly reduced nitrogen oxides to 0.06 g / km and 0.18 g / km, respectively. Only one issue has changed radically. A restriction has been introduced for solid particles in diesel – from 0.025 to 0.005g / km.
The Euro 6 standard currently applies, introduced one innovation. Nitrogen oxides in diesel cars have reduced their permissible concentration to 0.08 g / km. It should be noted that the Euro 6 standard reduces particulate emissions by 97%. In turn, carbon dioxide up to 6 times compared to the first Euro 1.

Control of exhaust emissions

Every car authorized for sale in the European Union passes the homologation track. It verifies that all EU regulations regarding environmental protection, safety and compliance with the production date are met. The tests also include laboratory tests that examine nitrogen oxides and particles that do not exceed 100 nanometres.
However, this method is to be changed. It take place in two stages, and the discrepancy between them should not exceed 2.1. Additionally, in 2020, a new stage will be introduced to examine the margin of error (tolerance). The announced changes affect car companies that need to improve their offers of cars sold.

Emission standards in the EU

Emission standards in the EU

Emission standards in the EU countries

In most EU countries, there are so-called ecological badges or dust badges. The first appeared in 2006 and over time they gain more and more popularity. They are not only confirmation of the fulfilment of individual Euro standards, but also entitle the owners to enter ecological zones.

Depending on the date of the first registration of the car, these are for example (for passenger cars):

• Euro 4 for Diesel 2006-2010
• norm Euro 1-4 for gasoline 1993-2010
• Euro 5 for Diesel or gasoline 2011-08.2015
• Euro 6 for Diesel or gasoline after 09.2015

You can not enter German and Austrian city centres without having a green ecological badge. It is the responsibility of the local authorities to designate the boundaries of the zones. Sometimes they are cities themselves, sometimes regions (eg Tyrol or Burgenland) or even sections of highways.

Usually the zones are permanent. But in France we will find zones depending on weather conditions (ZPA). There restrictions are in force during the period of increased air pollution. Therefore, being on the Seine, it is worth following local messages.

Each country also sets its own badges and their scale:

• France – 6-levels Crit-Air
• Austria – 6-levels Umwelt-Pickerl
• Germany – 3-levelsUmwelt-Plakette + Blaue Plakette
• Belgium – 1-level REG-Certificate
• Denmark – 1-level EcoSticker
• Spain – 1-level Distintivo Ambiental
• Czech Republic – 1-level Emisni Plaketa

Taking into account the fact that every new euro standard introduced many changes in recent years, we should not expect a reversal of this trend. Emission standards in the EU will change again and again. Especially that society and the European Union are becoming more and more pro-ecological. Therefore, it is not worth combining and exposing yourself to unpleasantness associated with excessive amount of fumes.
The more that there are ways to prevent this. For example, it is enough to have a good quality particle filter and to keep the exhaust system in good condition.

Smoke from the exhaust pipe

Categories:
smoke from the exhaust pipe

The fight against smog has recently become a common topic in many countries. Therefore, if we see excessive smoke from the car’s exhaust pipe, we should not ignore it. It has a negative impact on the environment. Besides, it may indicate some defect in the catalyst, DPF filter or another element of the exhaust system, or even greater defects, including the engine. A badly diagnosed fault can cause unnecessary and over-the-top repair, which will cost us a lot.

Smoke from the exhaust pipe, diagnostics by color

The colour and smell of smoke often allow us to diagnose a problem. Therefore, anything that comes out of the vehicle’s exhaust pipe cannot be underestimated in excessive amounts.

Blue smoke from the exhaust pipe

One of the most characteristic is blue smoke. Many drivers are terrified at seeing such smoke from the exhaust pipe. Rightly, you should not underestimate the signal that the car gives. When it appears at the morning launch of a car, it suggests burning oil in naturally aspirated engines.

More exactly it indicates to the wear of the elastics/valve seals. The heated engine acts as a sealant, while the cold one causes the droplets of oil to flow into the cylinder, then the blown oil flows out the exhaust pipe. The occurrence of smoke during the increase of the engine’s rotation is usually nothing but destroyed rings. During the addition of gas, the pressure is very high. After some time, the piston may not maintain its tightness, and as a result, the oil will get into the combustion chamber.

Cars equipped with a turbocharger can also experience a blue smoke sign. This condition occurs in the event of a leak. The oil gets then by blowing it together with the air. In this case, it is difficult to determine whether it is a turbine defect or piston rings.

smoke from the exhaust pipe, źródło wikipedia.pl, autor Steevven1

smoke from the exhaust pipe, źródło wikipedia.pl, autor Steevven1

White smoke from the exhaust pipe

White smoke, in turn, does not always indicate any problem. If after starting the engine in the morning white smoke appears, it is possible that it is water vapour, odourless, transparent. Unfortunately, another strong white smoke from the exhaust pipe does not catch up. Then another element comes to the combustion process — water. The standard diagnosis, in this case, is the gasket under the head. However, it is not always set correctly. Car owners who have an EGR cooler (exhaust gas recirculation valve) should take this into account. You can perform a test on the content of exhaust gases in the cooling system. When it comes out positively, prepare for higher costs. It is not enough to just replace the gaskets and perform a number of other tasks like planning, assembly, new timing.

Black smoke from the exhaust pipe

Another one is black smoke, which does not surprise anyone and is mainly assigned to cars with a diesel engine. Very often this happens because driving around the city causes driving below the revolutions of the turbocharger activation. When the black smoke from the exhaust pipe is still emitted after the gas is added, it is the result of inaccurate fuel combustion, i.e. incomplete combustion.

Black fumes can also have a connection to the injection system. This is when faulty injectors or exhaust gas cleaning systems are involved. Vehicles with combustion engines that supply petrol less frequently, but may also experience black smoke. It is possible that the engine then gets too much oil. The key may be a catalytic converter or a DPF filter because they stop the amount of soot being excessive. You need to be aware of the situation that the oil burned in the combustion chamber is the result of the failure of the cylinder head or bottom. At that moment it is worth answering whether the repair will pay off. An important tip is also the use of the correct oil, a simple thing, but sometimes neglected.

The last thing that can be responsible for the emission of black smoke is chip tuning. What is that? It is an improvement of the engine parameters, through interfering with the computer software that controls its work. This is possible because car manufacturers often leave a good deal of stock in terms of parameter adjustment. After overclocking the parameters may damage components such as the crank — piston system, gearbox, turbocharger, clutch, injectors or driveshafts. Catalyst and particulate filter are also exposed. A higher increase in exhaust emissions is observed.

Grey smoke from the exhaust pipe

One more colour of exhaust gases is possible — grey. Most often appearing immediately after starting the engine. The cold engine is then in the so-called suction process. It supplies a rich mixture to the combustion cylinders. If this condition persists for a long time, the engine temperature sensor is most often to blame.

That is why it is important to know what the colours of the smoke from the exhaust pipe mean. Thanks to this, it is possible to save not only time to find the cause of the fault but also money.

Flexible exhaust connector

Categories:
złącze elastyczne

A flexible exhaust connector is a small but essential part of the exhaust system. Choosing the right flexible connector will also protect other exhaust components, such as the catalyst, from too fast wear out and reduce the amount of vibrations generated by the engine.

What is a flexible exhaust connector and how does it work?

The flexible exhaust connector is also called the vibration damper. It consists of four layers – two main bellows, outer braid and inner braid or pipe. The main bellows are corrugated tubes that reduce vibrations. A purpose of the braid is to increase flexibility and protect against weather conditions.

The method of assembling the inner braid into the bellows is important. A good quality flexible connector ensures a constant flue gas flow diameter.

The vibrations that the motor produces are transferred to the following components of the exhaust system. The flexible connector is installed behind the exhaust manifold. It is a shield that eliminates some of the vibrations. As a result, further elements – catalyst, silencers and exhaust pipe – are no longer exposed to such high stresses.

What material is the flexible exhaust pipe connector made of?

The flexible connector should be made of high quality SS 304 steel or higher. This guarantees good resistance to vibrations, but also corrosion and high flue gas temperatures (approx. 600-700 °C). This element of the exhaust system will survive up to 4-5 years without any problems.

There are also worse products on the market. Those with a smaller admixture of nickel are more stainless, but also stiffer and less tolerant of vibrations. Another problem with low-grade steel is the quick rusting process. The lifetime of such flexible connector may be even not longer than 3-4 months, especially in countries with variable weather, i.e. where there is heavy rain or snow.

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Why is a flexible exhaust pipe connector so important?

As long as the exhaust connector is well-matched and works, everything is fine. Trouble starts when it begins to fail. There may be several reasons:

  • it is incorrectly mounted
  • made of poor steel, so too stiff
  • it just used up

At low-quality steel connectors, a frequent problem is shrinking internal braid, which can reduce the light flow by up to 30%. This, in turn, has an effect on less efficient exhaust emissions, and hence a decrease in engine power.

The shaky motor, which is not suppressed by the elastic connector, transfers the entire load to all parts of the exhaust system. The worst situation is for a catalyst that is not designed for these operating conditions and is closest to the exhaust manifold. As a consequence, the lifetime of the catalyst is reduced, but also silencers, exhaust pipes, handles and hangers.

Last but not least, the acoustics of the car are equally important. One of the first symptoms of abrasion of a flexible connector is knocking under the chassis. This has influence on lower driving comfort and lower driver concentration. And the damage can be done by accident – by hooking a high curb or a stone or gravel spatter from the tires.

Directional or typical connection?

There are two-way and unidirectional connections. The former operate independently, in which direction they are mounted. A directional connectors have a blue border on the exhaust side. The difference is in the arrangement of braid and parameters.

What to look for when replacing the flexible exhaust pipe connector?

If we purchase the connector on our own, we must first measure the length and diameter of the vibration damper. It is best if the measurement is very precise, eg with a caliper. It would be an unpleasant surprise if the new connector turned out to be a few millimeters too short.

Fortunately, this element of the exhaust system is most often universal and fits every brand and model. The length of the flexible connector varies between 60 and 350 mm and the diameter between 38 and 90 mm.

Of course, dedicated vibration dampers are produced for individual brands. We would install special elements in Citroen C5, Audi A4, A3 and A6, Volkswagen Passat and Golf, Renault Laguna, Megane, Thalia and Scenic, Fiat Palio, Punto, Seicento and Siena, Seat Cordoba, Leon, Toledo and Ibiza, Skoda Octavia, Volvo S40 and V40. They have a flange, on the one hand, which eases assembly.