Repair machine | Volkswagen burns oil, most of which are faulty here
February 25, 2022
Case: Some time ago, I took over a Skoda Haorui with a displacement of 2.0T (the EA888 used by Volkswagen's 1.8T and 2.0T). The customer responded that the oil consumption was serious, and one liter of oil had to be replenished for 1,000 kilometers.
After picking up the car, I checked the car and found that the front and rear oil seals of the crankshaft, the turbocharger and the valve cover have no obvious traces of oil leakage! Based on previous experience and the analysis of the principle of forced ventilation of the crankcase, it is suspected that the oil and gas separation inside the forced ventilation valve of the crankcase is not good, resulting in the unseparated oil vapor directly entering the intake manifold and burning. Sure enough, as soon as the pipe on the crankcase forced ventilation valve was pulled out, the oil dripped straight out. The intake hose at the throttle is also full of oil.
It is the place pointed out in the picture, the oil enters the intake pipe from here and burns directly! When the vehicle came, there was still a fuel adjustment fault code, which caused the engine fault light to turn on. Using the diagnostic instrument to check the data, it was found that the fuel adjustment was biased towards the rich direction. During the test drive, it was found that the tachometer would stay at 1500 for a short time after the gas was completely released at idle speed. can't turn back Combine the fault codes to analyze the fault phenomenon. Is it a stuck throttle or a slight leak somewhere? After turning on the key and stepping on the accelerator to hear the throttle flap action, there is indeed a dry grinding noise, so after cleaning the throttle and matching the test drive, the situation has improved slightly, but there is still no practical solution. Observing the periphery, using the chemical solution to do experiments on the pipe joints, no air leakage was found. Could it be that the forced ventilation valve of the crankcase is not closed tightly when idling? So I removed the place indicated in the picture, blocked it with rubber, and then tested the car. It was found that the idling tachometer would quickly drop to the 800 rpm position. The problem was found. The crankcase forced ventilation valve was stuck when idling!
After a test drive, everything was fine. The customer returned to the factory for inspection after running 3,000 kilometers, and the oil consumption was significantly improved, and it was in the upper-middle position.
