Everything about the turbocharger:

function, damage, symptoms!

Reading time 14 Minutes

A turbocharger is a widely used auto part and is used in both a diesel engine and a
gasoline engine. The turbo is also called an exhaust gas turbocharger. It is also so
called because it uses the energy of the exhaust gases from the engine. The
turbocharger supplies the engine with additional fresh air, thereby increasing the
power of the engine. The turbo charger is particularly popular with tuners. For the
ultimate driving pleasure, a modified turbocharger is next to a good one
Chiptuningto Exhaust System and a Air Intake System always a good addition.
However, a turbocharger is also a common source of error. The following article
explains all the important facts about the turbocharger, the most common causes
of problems, and what you can do about them.

Turbocharger - further development

As already described, an exhaust gas turbocharger (ATL) is used to increase the

performance of internal combustion engines and is therefore widespread. Due to
the advanced technology nowadays, turbochargers are now standard in vehicles
and are important for the current downsizing trend. Because if a good turbocharger
is available, a smaller engine with less displacement can be used without loss of
power. In times of climate protection, this is an important aspect, as it can also
reduce fuel consumption and exhaust gases. But there is not only encouragement
for the use of turbochargers. Because this type of technology is sometimes
expensive and can cause serious engine damage.

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1. Naturally aspirated engines are usually more durable

2. Function of a turbocharger
3. the intercooler
4. the boost pressure control
5. more boost pressure = more power
6. Variable turbine geometry (VTG)
7. Biturbo / twin turbo engines
8. Turbocharger and the turbo lag
9. sequential charging
10. Register charging
11. electric turbocharger
12. Defects on the turbocharger what?
13. Cleaning the turbocharger
14. the soot particle filter
15. Noise from the turbocharger
16. Foreign bodies as the cause
17. Identify problems
18. Turbocharger damage / action
19. Repair of the turbocharger
20. Turbocharger with warranty
21. Turbo exchange tutorials

Pure naturally aspirated engines are usually more durable

And there is the view that there is no substitute for displacement, except through
even more displacement. Thus, the turbocharger is not welcomed and used
everywhere. Nevertheless, since 2000, the large displacement has been replaced
with a turbocharger more and more frequently. As a person who is not familiar with
it, you may not have noticed anything. Because the performance of the cars has
even increased dramatically since then. This type of engine technology is known in
specialist circles, as already mentioned, "downsizing": With fewer cylinders and
less displacement, you get the same performance with less fuel consumption. The
pollutant emissions are also lower. Today's attitude towards the new cars is more
like: less is more. Nevertheless, you want to bring a lot of performance to the road.
The use of a turbocharger is inevitable. Even if this has a negative impact on
durability. Normally, a small three-cylinder engine with +250 PS does not last as
long as a classic 5 liter V8 vacuum cleaner. (Back to overview)

What exactly is the function of a turbocharger?

A so-called exhaust gas turbocharger uses the energy of the exhaust gas. The
engine is basically "charged" with fresh air. This leads to an increase in engine
performance. When you think of a turbocharger, you can basically think of two
turbines. There is also a turbine wheel and a compressor wheel. These parts are
connected to one another via a shaft. However, they are installed in separate
housings. The turbine wheel is located in the exhaust tract of the engine. Due to the
pressure caused by the hot exhaust gases, the turbine starts up. The turbine
rotates up to 300.000 rpm. The compressor wheel, which is connected by the
engine's intake system, also rotates at a similar speed. The compressor wheel also
provides fresh air and it is then pressed into the cylinder. (Back to overview)

a charge air cooler is one of them

Then there is the injected fuel. Ultimately, this has the effect of increasing
performance. A turbocharger belongs to a class, especially with more powerful
machines Intercooler. This is supposed to dissipate the heat that is created by the
pressure and movements. This ensures cooling and, in turn, increases performance.
Without a turbocharger, the engines would suck the fresh air into the engine
compartment by themselves using the negative pressure in the cylinder. However,
this variant is less efficient with the same force values. (Back to overview)

What a boost pressure control is!

The whole thing has to be regulated so that the speed does not get into the “red”,
i.e. the critical area. Otherwise you would overload the turbocharger and, in the long
run, the entire engine. That of course leads to damage. To avoid that, you have a
solution in the form of a Boost pressure control created. The whole thing happens
via a valve (Wastegate valve), which is installed on the exhaust side of the
turbocharger. When this valve is open, the exhaust gases bypass the turbine wheel.
This reduces the speed of the turbine and lowers the boost pressure. How far and
especially when this valve opens is determined by a Vacuum unit certainly. This
consists of a special membrane and a spring. Both are connected to one another
via a line on the fresh air side of the turbocharger. When a certain pressure is
reached, this membrane reacts and the pressure is reduced. (Back to overview)

How more boost pressure brings more power

Often, a maximum boost pressure is aimed for, especially in the tuning scene. That
would mean an increase in engine power. The spring tension is increased so that
this state is achieved despite the charge pressure regulation. As a result, the
membrane opens later because it needs more pressure to open. Steam wheels
were also widely used in earlier times. An additional valve used reduced the
pressure that reached the vacuum unit. The part is called boost controller, as the
valve could be controlled from inside the car. Another method to achieve this is of
course the "Chiptuning". The whole thing is controlled by electromagnetic valves,
which can then be programmed if desired. (Back to overview)

Variable Turbine Geometry (VTG)?

Another variant is the VTG loader This is increasingly used in diesel engines.
Instead of the valve with the membrane, there are so-called guide vanes, which
then control the flow of the exhaust gases onto the exhaust gas turbine. As with the
valve with the diaphragm, the guide vanes are controlled by an interlocking unit in
the vacuum unit. When the guide vanes are closed, the exhaust gas stream is
channeled past the turbine. If you keep the speed in the medium to low range, the
blades open only a little. This causes the flow to flow to the turbine and promotes
the response behavior. You have to imagine that the speed of the exhaust gas flow
that hits the turbines is very high. The turbine blades also create a higher leverage
effect. When full load is reached, the blades open completely so that a maximum
amount of exhaust gas flows in. This means that the turbocharger reaches a higher
speed and the boost pressure increases. Due to their sensitivity to higher
temperatures, the VTG turbines were mostly only used in diesel engines until
recently. In order to reduce the sensitivity, one must use more expensive parts.
Porsche, for example, uses such VTG chargers in gasoline engines. (Back to
overview)

What are biturbo / twin-turbo engines?

Most engines today have two turbochargers. At least when more than 4 cylinders
are used. Exceptions, of course, confirm the rule. An engine with two turbos is
generally referred to as a twin-turbo or a biturbo engine. Instead of one large
turbocharger, two smaller ones are used. These share the work or the exhaust gas
flow from the engine. This has the advantage that there is not so much stress on a
component. For example, if you were using a V6, two turbochargers would each
take care of three cylinders. Another advantage is that the smaller turbochargers do
not need the high speeds. This means that the small turbochargers need less
energy to achieve a high boost pressure. (Back to overview)

a turbocharger -> often large turbo lag

With a large turbocharger, the engine works like a naturally aspirated engine until
the correct boost pressure is built up, with significantly less power. The lack of
power up to a certain speed is also known as turbo lag. This phenomenon used to
be typical of turbo engines in the 80s and 90s. The solution with smaller
turbochargers is therefore very promising. One of the few models is the Bugatti
Veyron, which uses four turbochargers. BMW has also already used an engine
(engine type: B57D30S0) with four turbochargers with the quad turbo diesel. The
top diesel was used in the BMW 750d xDrive and also in the 5, X5, X6 & X7. With
400 hp and 760 Nm, it provided plenty of thrust in all situations. But in the second
half of 2020, the engine was removed from the European engine portfolio. BMW
named the changed political, social and market conditions in Europe as the reason.
(Back to overview)

sequential charging

But there are also alternatives to the double turbocharger. Some machines are
equipped with a large and a small turbocharger. This improves the response at low
speed. At the time of start-up, the small turbocharger does the main work. From a
higher speed, the large turbo takes over the work. This largely avoids the turbo lag.
In the middle area, the two turbochargers even work together at times. This is
referred to as sequential charging or sequential biturbo. (Back to overview)

Register charging

Turbolader Register…

Register charging is something else. The difference here is that the turbochargers
act alternately. But here, too, the low speed is more intended for the smaller
turbocharger, with the large charger working at higher speeds. A switchover flap is
used to switch between the loaders. The exhaust pressure also plays a major role
here. In this variant, however, the turbochargers never work in tandem. Both run
alone. (Back to overview)

electric turbocharger

By the way, more and more is going to one electric turbocharger set. For example
with the new E-Booster from BorgWarner. The first series use of this loader is in the
six-cylinder petrol engine in the new W223 S-Class. The system celebrated its
premiere with the Audi SQ7 in 2019. The E-Turbo of the S-Class accelerates to 0,27
revolutions within 70.000 seconds. Early on during the journey through the rev
range, the system generates so much steam that the torque curve increases
significantly. An exhaust gas turbocharger cannot do this for physical reasons. The
electric charger is connected in series with the exhaust gas turbocharger. Instead of
the turbine wheel, the E-Turbo has installed a small electric motor that drives the
compressor wheel. In the lower speed range, the bypass flap is closed when
accelerating and this brings the air to the e-compressor. This is the conventional
turbo downstream. It provides pressure until the exhaust gas turbo can produce
enough boost pressure itself. (Back to overview)

Defects on the turbocharger what?

The concern of some car owners that wear and tear is the cause of defects is often
unfounded. An insufficient oil supply is more likely the problem. During the
mechanical movements inside the turbocharger, the gaps are permanently
lubricated with oil. However, if there is not enough oil in the circuit, grooves may
form on the bearing surfaces of the shaft. This can cause the material to become
porous and tear. Poor oil quality can also be the cause. Foreign bodies could also be
a cause. If the oil filter is clogged, fuel or dirt can get there. You should also avoid
turning off the engine when it is hot, which can be the case if you have driven long
distances at high revs. After switching off the motor, the mechanics are then no
longer cooled. Everything can get very hot for a short time before it cools down
again. Burning oil in the engine compartment is also counterproductive. The
resulting oil carbon blocks the lines and it is also deposited on the turbine. As a
result, the turbocharger can no longer work properly. (Back to overview)

Cleaning the turbocharger

For cleaning you don't have to be very knowledgeable. There are, for example,
special cleaning sprays that can be applied directly without removing the
turbocharger. This is not particularly expensive and can be done by anyone. It's
best to buy a complete set. If you are unsure, you can also have the turbo cleaned
by a specialist. However, this is not quite as cheap as lending a hand yourself. The
result is usually better than with a simple Turbo Clean Set (turbo cleaner). Such a
set is definitely an alternative for regular cleaning in between. In any case, better
than not worrying about it at all. (Back to overview)

Soot particle filter as the cause of turbo damage

A possible cause of functional problems can also be malfunctions in the exhaust

system. Diesel engines are particularly affected with their Rußpartikelfilter.
Problems occur most often when the vehicle covers mostly short journeys.
Unfortunately, this is often the case in city traffic. The particle filter then clogs very
quickly. The scenario can be prevented by driving longer distances where the DPF
filter can burn itself out. If the filter gets stuck, the smallest soot particles get stuck