[yoyo458]

Hello all,
I own a BMW 120d LCI F20 that I bought new in 2016, and have done over 140,000km in it. A little over a year ago, I did an engine remap, and about 2 months after that, I had a noise that would occur whenever the turbos would engage. I was extremely worried at first, and when I got the car checked, it turned out it was the Gasket Steel between the exhaust manifold and the engine block that was leaking some air(Part number 11628509783). After changing these very cheap parts out, the sound has completely disappeared. Up until about a week ago when it started again. I wanted to know if anyone else has had experience with this problem, and if the source of the problem genuinely is the gasket steel. I have seen another car with the same sound that I have, and have seen that it removed after replacing these gasket steels, but although the part is cheap, the time it takes to remove it is very long.

[iEmrecaN]

Unfortunately, I have been dealing with this exact issue for months. The root cause is your exhaust manifold. Due to a persistent gas leak, the manifold has likely warped over time. The only proper solution is to have it resurfaced with precision machining or replace it entirely. Otherwise, no matter how many times you replace the gasket, the leak will persist.