The assumption was that the VANOS was being cycled through its range. The sound got me a bit concerned and I had a bit of difficulty turning the activation off. Managed to turn INPA off with the VANOS still activated on the car, Ediabas running and the cable still connected e.g. correct running conditions to run Testo to log the VANOS operation. All, I replaced the oil filter housing (OFH) gasket on my 2003 325i Touring two weeks ago. The left side of the engine had all the typical OFH leak symptoms. I cleaned up the area as best it could. I knew, though, that wasn't the only oil leak I occasionally get a whiff of "burned oil Potentially allowing richer mixture into the cats making them work harder and eventually fouling them out. Suspect that is why my car has the check engine codes for the cats at 123k miles. Also, side note. When talking with a BMW senior engineer about the Vanos system he commented this. "BMW recommends premium top tier fuel for a reason. Although as mentioned in some cases it can leak oil from the electrical connector and does need replacement. Here's how to check and resolve a sticking vanos exhaust solenoid valve. With the vanos mounted on the engine, remove the vanos exhaust solenoid with a 32mm deep socket. Most 32mm deep sockets aren***8217;t deep enough for the vanos The VANOS unit sits at the top front of the engine. When the bolt heads shear off, they basically drop straight down the front of the engine to the oil pan. The oil pump pickup has a screen to keep large debris out of the pump. You have an oil filter to catch any small stuff (not that there would be any, in this case). These vanos units utilize engine oil and pistons/cylinders to manipulate the positioning of gears to facilitate variable valve timing. The seals on the pistons are leaking due to deteriorating seal O-rings. This leakage is causing the vanos to fail in its function. Although Valvetronic is a complicated system compared to most others of its kind, it allows for infinite adjustment in combination with BMW VANOS. Valves can move from 0.18 mm lift all the way to 9.7 mm lift, in a fraction of a second, and your BMW’s DME gets to say just how far the valves open. Atmospheric Pressure Right at the Intake Valve Vay Tiền Nhanh Chỉ Cần Cmnd.

how does bmw vanos work