2001 BMW 325i Q&A
2001 BMW 325i Question: Hello, I have a BMW 325i E46. OBD II reading of P1156, P0172 and P0175.
I've been working this issue for some time now. I have cleaned the throttle body, idle control, replace all O2 sensors, The MAF, The MAP, cleaned the Fuel Injectors, replace the Temp sensor, replaced all air filters, all the airlines, the fuel filter and the pressure control valve. I cannot think what else I can do? I sent it to a Bosch shop and they couldn't figure it out. My Gas mileage is about 16.3mpg and it idles badly from the start but smooth’s out after about a minute. I really don't want to send it to the shop and was wondering if there are a couple of DIY things I can do before wasting my money at a Dealership. Thanks - Butlertims
did you have the coolant sensor checked at the bosch shop?? Roy - mastertech6371
Rough idle and poor gas mileage could be a sign of worn VANOS seals. Many M52 engines need to do a VANOS reseal after about 120k, sometimes sooner. - EA Motors
Try the oil separator under the intake manifold. - Msanjsanksan