joge

2010 E60 with N54 engine 175,000 miles.........Walnut cleaning of intakes done, replaced valve cover, replaced MAP sensor and boost sensor, smoke tested for vacuum leaks, been to 2 garages that specialize in BMW's neither could pin point what the issue is that keeps setting the P0171 and P0174 error codes. Runs rough and dies off and on. Any suggestions ?

Could it be a vanos problem with this many miles ?

Feedback is much appreciated :O)

eraVulgaris41

any update?

bhughes

Have you replaced upstream O2 sensors? This is pretty much a maintenance item. With both cylinders involved I would check fuel pressure, high and low first. Rarely do mechanics check the low fuel pressure because it's not read by the scanner. With it stalling at idle, I would like to see all codes. Maf sensor should be around 21/2-4 g/s depending on idle speed. I've purchased aftermarket maf sensors that were wrong out of the box. Not knowing the other codes, dying lean at idle should be rather easy to find. Spray a little starting fluid or carbon clean into the air filter assembly would tell you right off that it isn't getting enough fuel. It should straighten out and run well. If it doesn't you're not lean. I would be interested if all cylinders are misfiring or are some ok, that's why we need all the codes. Also, if it does run well with added fuel, try spraying away from the air filter assembly, around the intake and intake gasket. Little sprays, not continuous where fire may result.