If you are too lazy to read — go straight to the end of the article, there is a clear picture with graphs and results of our work. I recommend the rest to familiarize themselves with the theory first.
Previously, I wrote about the typical problems faced by owners of EP6*T engine family with direct fuel injection. These include timing chain stretch, valve and turbo failures, piston burning — as well as carbon buildup on intake valves.
There is an opinion that if you change the oil frequently, there will be no carbon buildup on the valves. There are also numerous stories that "if you pour oil from company XXX for YYY money, then there will definitely be no carbon buildup". The height of absurdity regarding carbon buildup are the tales that "bad gasoline clogs the valves" ))))
To begin with, it is worth explaining why there is carbon buildup on the intake valves in an engine with direct injection. The fact is that unlike engines with port fuel injection, where fuel is supplied through the intake manifold, in direct injection engines, it is supplied directly into the combustion chamber bypassing the intake tract. This leads to the intake valves not being washed by fuel, and the oil that naturally gets on them during operation starts to burn.
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This is what it looks like (examples from my personal cars):
Carbon buildup on PSA: www.drive2.ru/l/4062246863888571590/
Carbon buildup on VAG: www.drive2.ru/l/4416290/
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As you understand from the description, carbon buildup on the valves appears in any case, just somewhere earlier ("vegetable operation" and idle hours), somewhere later. As can be seen from the principle of operation of the direct injection engine, gasoline cannot get to the intake valves at all, and its quality has nothing to do with it. Similarly, the quality of the oil and the frequency of its change do not solve the problem, but at most only postpone it a little.
As a result, depending on the type of engine and its operation, the problem manifests itself sooner or later.
For the PSA group, this is 40-50 thousand kilometers, for the VAG group, it is closer to 80-100 thousand kilometers.
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What can solve this problem (links to solutions inside!)?
— Installation of a methanol injection system (helps, but does not cure; but the spark plugs are always great!)
— Installation of an aftermarket or updated stock oil separator
— Timely replacement of valve stem seals
— Timely replacement of engine oil (changing it more often than the norm won't help, but it cannot be neglected)
— Cleaning by filling the intake for a day with LAVR or Wynn's mixtures (helps, but does not completely clean)
— Mechanical cleaning with removal of the cylinder head (the only 100% reliable option)
— Buying cars with new generation engines (Gen.3) with a dual injection system
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Well, now let's move on to the promised graph )))
A long time ago, I wanted to show clients how carbon buildup on the valves affects the power of the car.
In our example, we consider the Peugeot 207 1.6 THP156, which should have 150+ horsepower in stock. When the car came for chiptuning, the mileage was already significant and the car clearly did not develop the proper power. The carbon buildup consumed 23 "horses" and only 133 horsepower remained!
After cleaning the intake valves, we took a repeat power measurement — and, oh miracle, we got 156 horsepower! Everything was clear, as if it had just rolled off the assembly line )))
Well, then there was the proprietary Etuners firmware for 95 gasoline, and 194 hp at the output!
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PS. If you have a PSA or VAG and you plan to clean the intake valves and cylinder head — we can help with that! )))
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PPS: taking this opportunity, I remind you about:
There will be no discounts (18+): we have already removed everything unnecessary!
and about extra parts for front-wheel drive:
Extra parts after installing all-wheel drive?!
Plus, a set of the stiffest H&R springs with a drop and a mileage of 15 thousand km has become available. They don't pinch anywhere, always fit the topic, and look super!
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Below are the remnants of didactic material.
You will find links to this material in this article — everything is described in great detail on each topic.
