For a long time I had an exhaust gas odour when the engine was running in the interior. The whole thing is already described in the following thread from page 7 but so that the thread is not further diluted, I separate it and open a new one.http://www.motor-talk.de/…/…-642-special tool-t5491504.html?… Today I wanted to expand the turbo because 2 turbo repairers of the opinion were the fault source is not the turbo but the exhaust system. from the control shaft (light soot deposits), the cause should be the exhaust system with too high exhaust pressure. The sensor exhaust back pressure delivers normal values with and without cats and DPF. To test and reduce the exhaust back pressure I built and mounted 3 atrappen (2 Kats and 1 DPF). Result of the engine runs as always, only in a warm state at the traffic light it smells in the interior after I had worked from the front to the turbo and in the rear Bereic h had removed the exhaust, I came to disassembly the exhaust pipe from the exhaust to the AGR cooler. I had already looked into this line with the endoscope but didn’t see anything. After the removal of the exhaust pipe, soot was visible on the lower flange outside, but the sealing surfaces were blank. After looking carefully, I discovered the crack. Probably the exhaust gas leaked out there and rose again under the turbo. I hope that was the source of the fault. When ordering parts there is a small problem. The charging air line from the noise damper to the turbo is sealed with 2 sealing rings. The sealing ring on the turbo is ordered but the noise damper does not find the part man and wants to sell me a new noise damper A 642 140 19 87 for approx. 140 €. The O-ring on the noise damper has the approx. dimensions 52,0×4,0. Who of you already has the charge air cable dich can I use his invoice to give me the part number for the O-ring on the silencer?