Defects and Their Causes

Common turbocharger defects and problems and their causes!

Each turbocharger is an extremely robust component and is designed to work smoothly as long as the engine is in good condition and the related components such as electronic components, turbo system and exhaust system, etc. are in good condition. Unfortunately, however, the turbocharger is often damaged, and the reasons for this are usually not due to it. Here we will try to explain many of the causes of the most common failures.

1. Insufficient pressure and lack of engine oil.

In case of problems with lubrication, oil pressure, poor lubrication of the turbocharger occurs, which leads to excessive wear of the shaft and bearings. Modern turbochargers develop from 130,000 to 300,000 revolutions per minute. At such high speeds, it is of paramount importance that the friction elements are constantly lubricated. A common problem is poor lubrication due to irregular oil and filter changes or even lack of oil in the turbo. Lack of engine oil occurs when there is a blockage in the oil lines (these are the tubes that lead oil to the turbo). Such a lack of lubrication and blockage can be due to various reasons, such as sediment, poor quality oil, oil with a high soot content, hardened (carbonized) oil, etc. In some car models, there are factory-installed fine oil filters that become clogged and limit the flow of oil. Poor quality or old, irregularly changed engine oil is also a common cause of turbo damage. Here are some pictures of damage caused by poor lubrication.

2. Impacts and damage to the turbine and compression vane.

When the turbocharger is operating, it sucks in a large amount of air through the air filter, the lack of an air filter or the presence of a poor-quality one or one that is not regularly replaced, leads to the ingress of foreign bodies, or insufficient permeability, etc. and accordingly leads to damage to the compressor compression (cold) vane. An example of this is when an external foreign body passes through the vane while it is rotating and injures it. The same applies to the turbine (hot) vane. For example, this could be remnants of old particles from a previous turbo, a breakdown of the exhaust manifold, carbon deposits or the like, which could damage the turbocharger in a split second.

3. Excessive temperatures and overheating.

Turbochargers are generally exposed to strong temperature ranges and changes, with diesel engines reaching temperatures of the order of 800 - 850 C°, and with gasoline engines up to over 1000 - 1100 C°! Reasons such as a problematic fuel system lead to exceeding these temperature limits and overheating of the turbocharger. For example, in gasoline engines, when the fuel supply system weakens and a mixture is too lean, the temperature of the exhaust gases rises excessively and the turbo overheats. In diesel engines, perhaps the main cause of overheating is defective injectors (so-called peeing nozzles). Overheating is most often expressed in blueing of the axis that connects the blades, this sign - blueing means that the metal has overheated and has lost strength and elasticity because its structure changes, that is, it becomes softer and bends much more easily. A crooked shaft leads to a strong imbalance, and an imbalance in the turbocharger is a sure guarantee of breakage, here are some photos:

4. High pressure of the turbocharger and overcharging.

Turbochargers are equipped with an unloading mechanism, it protects against overload (some large turbochargers of tractors, trucks, etc. are an exception). When the unloading mechanism is damaged and does not work, the turbocharger begins to raise the operating pressure of the compressed air uncontrollably high, which actually means that it works at higher and higher speeds than the set ones, and this is critical for it. When reaching and exceeding certain speeds, the turbocharger collapses from overload and is damaged accordingly. When operating at extremely high speeds, this leads to imbalance, because each turbocharger is designed and balanced to a certain range - a ceiling of speeds set by the manufacturer, which should not be exceeded. With a blocked and inoperative variable geometry VNT is the most common example of a faulty unloading mechanism. When the variable geometry is blocked in the closed position due to soot, the turbocharger creates as much pressure as it can until it finally fails. There are also frequent cases with Waste gate turbochargers, where the pneumatic valve controlling the gate is blocked or is not controlled due to broken vacuum hoses, the end result is certain and this is damage to the turbocharger. Now comes the moment when we must not forget incompetent "masters" "services" who do things that they do not understand at all, such as manipulating the unloading mechanisms for the purpose of "supposedly" perhaps more power, which is absolutely false and as a result of which the turbocharger does not work adequately and the effect in the end is another failure. Adjusting the variable geometry and wastegate is a precise task and should not be done without the presence of special machines FLOW Bench stands and preparation! Strong overinflation can also be caused by faulty electro-pneumatic valves, known as N75, these mechanisms control the unloading valves and in the event of a malfunction, the entire system is out of order and does not function properly. Here are some pictures:

5. Leakage and blockage in the exhaust system

When the engine exhaust system is clogged, most often due to a clogged catalyst, clogged canisters from their breakdown or a clogged particulate filter, a lot of exhaust gases under pressure collect between the turbocharger and the clogged area. In such a situation, these gases cannot leave and exit in time through the exhaust system, that is, the generation of the car and give off their heat, thus leading to severe heating and overheating of the turbocharger. When this happens, a problem occurs that the increased pressure of the exhaust gases, known as back pressure, exerts a huge back pressure, that is, pressure on the turbocharger in the direction of the axis and thus leads to premature wear of the turbo's axial bearing as well as an increase in temperatures and bursting of the hot snail. Here are some more illustrative photos:

6. DPF/FAP particulate filter and related problems.

In modern diesel engines, manufacturers install particulate filters to meet strict environmental requirements, for this reason, more and more diesel cars are equipped with this filter, called DPF by some manufacturers, FAP by others. The purpose of this filter is to collect the soot produced during engine operation, after a certain time when the filter is almost clogged with soot and the car's electronics see this through the sensors with which the system is equipped, it starts a self-cleaning process called regeneration. What is regeneration? - The engine changes its operating parameters and thus manages to ignite the soot collected in the filter, to make the ignition safer, some cars even inject a special flammable liquid into the exhaust system, and others diesel fuel, when this happens and once it enters regeneration and ignites the soot, it begins to burn, the process lasts for a different time, from 10 to 30 minutes usually. The process itself can be compared to a smoldering chimney, during this regeneration, extreme temperatures develop in the immediate vicinity of the turbocharger, and in some cars the DPF filter is attached directly to the turbocharger, so installed that during each regeneration the ignited soot burns in it itself. The result of all this leads to pure and simple overheating! It is not uncommon for the car to enter this process more and more often and perform frequent regenerations, for example, this is considered to be every 200 - 300 km, and this means only one thing - a malfunction, and a process that repeats more and more often means almost constant overheating of the turbocharger. We can safely say that this particulate filter is one of the biggest "killers" of the turbocharger. Here you can see a clogged and disintegrating one:

7. Incorrect, bad and missing balance of the middle body (CHRA).

Recently, it has become increasingly difficult for a person to sift out the quality turbocharger from the garbage on the market. The offers of dishonest traders and pseudo "turbo services" who DO NOT HAVE a balance machine, have no skills, but the important thing is to sell... Most of them sell middle parts / bodies that are "ALREADY" balanced during their production at the factory and are accompanied by a graph which is also "ALREADY" proof, namely here WE can say YES but NO, because if you put such a middle part on a balance machine, you will see for yourself that the graph does not correspond, or is up to certain rpm lower, for example, or OTHERWISE it is put for beauty, and the balance is subject to all kinds of criticism. In practice, when you buy an unbalanced part at a very low price, of unknown quality and origin, for example a Chinese part, you are buying a part that will last extremely little. In the absence of quality balance, this will certainly cause the turbocharger to break in the shortest possible time. Recently, it has been "Modern" not to say "HABIT" for many companies to lie that they have balancing machines, which is incorrect and is another Bulgarian phenomenon like "what's so wrong, one repair kit and that's it", but this still leads to a result of which is again a lack of balance and damage to the turbocharger. For us, it is even mandatory to note incorrect companies that have some (quality or poor quality) balancing machine that has never been overhauled, that is over 10 years old and its accuracy is questionable, etc. The worst thing is that in their pursuit of ever-increasing and maximum profit, these "services" and "companies" use old parts (nothing is thrown away), namely overheated axles (i.e. a crooked axle), damaged blades (old compressor blades that have an injury that is finely concealed with a file) or as we have been hearing lately about a type of turbocharger repair - "gap removal"... Such parts are impossible to balance even with the best balancing machine, they are simply defective and cannot provide a quality finish when repairing the turbocharger. A recycled turbocharger with defective parts certainly means a lack of balance and headaches and subsequent problems and in some cases even engine failure. Here are some more pictures

And here you can see an EXAMPLE OF pseudo turbo services after a "repair" of the turbocharger the client drove a full 50km then the turbocharger leaked and changed its sound, after dismantling by our team and what we saw we can say this is WHY you should trust professionals and not pseudo services:

8. Unprofessional and poor-quality remap / chip tuning.

Last on the list but not least as a problem leading to damage to the turbocharger is caused by poor-quality chip tuning, changing the settings of the car's electronics is a complex thing and it is too naive to think that every garage master who offers you a remap - chip, will do everything safely because recently everyone has become a "tuner"... . For good tuning (tuning) it is important to know the design features of the engine, its components and the limits of breakage, this does not mean that if you are a programmer you are also a "tuner" in any way, it is also necessary to fully know the mechanics of the car and how it works. With poor-quality tuning and example "we will raise the turbo a little", the turbocharger is subjected to a load exceeding its specifications many times and, as the "tuner" says, pumped up, too much (and unnecessarily at that), which always leads to one end, namely problems. Another example is a poorly tuned fuel mixture and combustion process (lean mixtures for gasoline, rich for diesel, incorrect advances, etc.) leading to these effects that have been seen, namely cars passing by you make clouds, because the tuning is poor quality and accordingly the turbocharger overheats! We can certainly say one thing and that is be sure that poor quality tuning will certainly damage your turbocharger (quickly). And yet here we must note that we are writing about POOR QUALITY tuning, because if everything is done properly and the tuning is correct, good tuning in no way threatens the health of your car and turbocharger.