Finally can not escape the curse of burning engine oil, overhaul EA837 homework!
First of all, I would like to introduce the situation of the car. In August 2012, the TSI gasoline high-end black Touareg, with a mileage of 152000 km when the overhaul entered the factory. Since 90% of the time is spent driving at a slow speed in the city (the average speed calculated by the computer is no more than 20 kilometers per hour), it began to burn oil at about 80, 000 kilometers, adding a liter at the beginning of 5000 kilometers and gradually growing to 3000 kilometers per liter. When it reached 2000 kilometers per liter in the first half of last year, we began to think about how to alleviate the development trend of burning engine oil. There are different opinions and opinions on the methods of non-demolition treatment. I have also been to several different local repair factories to test with endoscopes and cylinder pressure gauges. It is said that there is no major strain on the cylinder wall, that is, the burning of engine oil caused by carbon accumulation in the piston ring. But the principle of demolition-free treatment determines that it can only work for a period of time, and you still have to overhaul the engine once and for all. And the cost of demolition-free management is also thousands of large, the performance-to-price ratio is not high.
I am just a person who likes to ponder. Some riders in this group slowly release the piston ring by adding T6538 additive to the oil. I went to see the introduction of T6538 and decided to use this method to do the experiment. Of course, it is best to release the piston ring. If it doesn’t work, you can overhaul the engine. Anyway, you are psychologically prepared for the overhaul. In the purchase of T6538 at the same time, but also purchased in the same business PEA solution diluted to add to the gasoline, cleaning the carbon in the cylinder.
This is the introduction of PEA solution.
This is the introduction and usage of T6538.

By the end of last year, using the product according to the above usage, we can see with the endoscope that the carbon deposition in the cylinder has been partially cleaned, and the metal primary color is exposed at the top of the piston, indicating that the PEA solution has a certain effect. However, the problem of burning engine oil has not been alleviated, but is even more serious. Before the overhaul, one liter of engine oil must be added every 500km, otherwise the police will be alerted after running 1000 km of electronic oil dipstick. Except for burning oil, there is no abnormal noise or abnormality in the operation of the car engine. At this point, the method of releasing the piston ring with T6538 was a complete failure, and the oil-burning riders stopped trying and honestly overhauled it.
On March 12, I sent it to my friend’s repair shop to start an overhaul, and the owner of the repair shop took his two locks, high-end diesel oil, Touareg, and walked for me. To be honest, firewood is much more fuel-efficient than gasoline cars, but the engine vibrates and noises much louder than gasoline cars. For the sake of comfort, I’d rather pay more for gas.
Here are some pictures of the overhaul:
Lift down the engine:

Taking apart the timing system, there is nothing wrong with the chain, the chain plate and the tensioner. To be on the safe side, the chain guideway and tensioner have been replaced. The chain of EA837 is much stronger than that of EA888. There is no elongation or deformation at all for more than one hundred thousand kilometers, and there is no need to replace it.
Taking apart the camshaft cover, it can be seen that there is more mud, which should be washed off the aging mud inside the engine after adding T6538 to the oil, and the deterioration speed of the oil is accelerated, resulting in the accumulation of sludge.

This picture shows that there is a lot of mud inside the engine.
The engine tile is basically not worn, except for a few large tile coating has a little trace, the other coatings are in good condition. 150000 kilometers of large watts, this condition is surprisingly good, so this overhaul did not replace the large watts.

Except for a long scratch on the second cylinder, all the cylinder walls are intact. Because it has been decided to bore the lower liner of the cylinder, the micrometer is not used to measure the wear of the cylinder wall. If the lower sleeve of the boring cylinder is not intended to replace only the original piston ring, the cylinder wall in this state can continue to be used.

Here comes the big deal. The third ring of the six pistons is all burned to death by carbon deposits, and has completely lost the function of scraping oil. Fortunately, although the coating on the side of the piston has been worn off, there are no scratches, and the wear is still within the allowable range after measurement, so there is no need to replace it, which saves a lot of money.

The shingles are scratched and worn, and they all have to be replaced.

There is a thick layer of mud inside the oil pan, which cannot be extracted by changing the oil, so it must be removed before it can be cleaned. So much sludge should have something to do with the use of T6538 cleaning. (the video cannot be uploaded after shooting, so we can only take a screenshot and put it up.)
The overhaul lasted 7 days, and the list of replacement parts is as follows:
In addition to the above accessories, this overhaul also used 7 liters of all-synthetic oil, 3 bottles of R134 refrigerant, boring cylinder with replacement valve oil seal to replace piston ring, replacement of car roof shed cloth, maintenance of pre-replacement air shock absorber, overhaul of wave box to replenish wave box oil, dismantling and maintenance generator and replacement of new carbon brush.
After the overhaul, the condition of the car basically returned to the silky state of the new car. After driving for nearly 1000 kilometers, no abnormality was found and the oil level did not drop. I was very satisfied.
Some thoughts and matters needing attention after overhaul:
1, do not think about relying on additives to solve the problem of carbon deposition and burning engine oil, EA837 carbon deposition, burning engine oil is the problem of tire belt, non-dismantling and other methods to cure the symptoms but not the root of the problem, the final solution is to overhaul and boring the cylinder. As for PEA solution, T6538 and other additives, don’t waste money no matter how cheap they are. From my experience, these things can lead to a sharp increase in engine sludge.
2. As to whether to replace the original piston ring (cylinder wall wear under the allowable limit) or boring cylinder lower sleeve for overhaul, I also struggled for a long time before the overhaul, and checked a lot of information. Some say that the original factory design is the most suitable, do not boring cylinder lower sleeve change wave ring change the original factory design, will lose power; alloy cylinder liner and aluminum alloy middle cylinder thermal expansion coefficient is different, high temperature will lead to cylinder pulling; cylinder spacing becomes smaller after boring cylinder, strength reduction and so on. They suggest that if the cylinder diameter wear does not exceed the limit, only replace the original factory small hole piston ring, and then thoroughly clean the carbon deposition every 30,000 kilometers to prevent oil burning. Before this overhaul, I communicated repeatedly with the owner of the repair shop and finally decided to replace the wave ring under the boring cylinder for overhaul. The repair shop has taken this method to overhaul at least dozens of EA837, many of which have run nearly 200000 kilometers, and none of them has a problem. As long as the processing level of the boring cylinder factory is in place, the repair factory installs in strict accordance with the maintenance manual and uses the original factory accessories, there will be no hidden trouble.
3. Finding a familiar and reliable repair shop is very important!!! The sense of responsibility and carefulness of the overhaul master are the most important determinant of the quality of the overhaul. He can not only discover and solve problems during the overhaul process, but also help you save money and time. As can be seen from the above parts list, this overhaul did not replace pistons, large bearings, etc. in a hurry, nor did it use major repair kits but used minor repair kits on demand. During this overhaul, the repair shop also solved the air damping problem and gearbox problem that had troubled me for a long time (will be described in detail below). If the maintenance personnel were impatient and careless, they would not repeatedly test and find the problem.
4. Regarding air damping: In March 2021, I posted a post about replacing the top glue to solve the air leakage from the air suspension. In October 2021, after discovering that the air leakage was still leaking, I simply replaced two pieces at another friend’s repair shop. The auxiliary factory front damping (2450 yuan x2, with a 2-year warranty). I had no place to put the original factory damping, so I dragged it over and placed it in the warehouse of this repair shop. During this overhaul, when I chatted with the repair shop, I mentioned that the shock absorber effect of the auxiliary factory was much worse than that of the original factory. The boss took the original shock absorber I had left in his warehouse and took it to find another way to repair the shock absorber. Finally, he found that the last time the top glue was replaced, the top glue leaked slowly. After the top glue was replaced, the original shock absorber was repaired and replaced.
5. Gearbox problem: In the past two years, when cold cars started, we often heard a slight gurgling sound from the chassis. The Gearbox occasionally got into gear and did not move out. In addition, the Gearbox did not actively shift up. After this overhaul, the owner of the repair shop found that the gearbox was occasionally stuck in gear and would not move. After changing the glue on the machine foot, the steering wheel vibration was still greater than normal when it stepped on D gear. After repeated testing and elimination on the rack and putting in gear, it was found that it was caused by insufficient oil in the gearbox (insufficient oil in the gearbox caused the valve body to not move properly and could not be put in gear, and there was air in the gearbox caused the gears to make noises when stirring the oil). After replenishing one liter of gearbox oil, it returned to normal, and there was no longer a gurgling sound. The gearbox upshifting also became very positive. When you stepped on and put it in D gear, the steering wheel vibration almost disappeared. This fault should be caused by the last time another repair shop did not add enough oil to the gearbox. Fortunately, there was only a little less oil, which would not cause abnormal wear on the gearbox. After running another 10,000 kilometers, you will feel even more at ease if you use a circulation machine to change the gearbox oil.
6. This overhaul also rewrapped the roof cloth inside the car. The original roof cloth had been degummed and sagging in many places, which was really unsightly and unbearable for patients with perfection.
Seven or five years ago, I posted a post about replacing the foot glue, and at that time it was the foot of Rundford (Owl). During this overhaul, it was found that the foot glue had collapsed and needed to be replaced. The repair shop recommends replacing the original factory loading equipment with Kotek, hoping that it will be more durable than owls.
8. You can use 5w30 engine oil after overhaul. It is recommended to replace it for 5000 kilometers for the first time, and you can replace it for 10,000 kilometers in the future. At the same time, don’t use any additives anymore, just check for carbon deposits regularly.
This overhaul has been completed so far, and the results are very satisfactory. In the future, I will update the usage and problems found for reference by other riders.