[coll_316ti]

right am having problems understanding this as some of you know i have been having a nightmare with my e46 compact it has a slight misfire at low revs but higher up the rev range the car is fine gets good fuel consumption pulls good through the gears

my problem is this bmw in grassicks have finaly after the car being up there on sevral ocasions that the car has only 40psi on one of the cylinders they say possibly a sticky valve broken valve or valve not seating properly

now i have replaced a bent valve on a nova many years ago and it was a constant misfire right through the rev range it was always there never went away

i understand my beemer aint no nova and has a way more sophisticated engine management system on it but would it not be only firing on 3 cylinders constantly if it was bent or broken valve ?

 

[Ronnie]

If the valve was bent or broken then yes it would only run on 3 cylinders and would sound awful.

Pulling the coils one at a time would pin point the cylinder not doing much work, but obviously the garage has found this now.