I am getting a misfire,and the coil packs,injecters and computer have been checked,also cam and crank sensers,The guy looking at it says #2 exaust valves are staying open causing miffire And thinks oil pump has to much pressure causing valve to stay open.Does this sound right
can the oil pump cause the valves to stay open,causing a misfire on 2006 Cadillac DTS
by J.T. in Winston, GA on December 25, 2011
2 answers 2 comments
ANSWER by mastertech6371 , December 25, 2011
i would think if one is open from oil pressure, then all should be open and it would not run. i would start with a compression test, both wet and dry. compression will verify his results. Roy
COMMENT by J.T. , December 30, 2011
I've had a compression test done,and # 2 valves are stuck open,I've done a engine flush and fuel induction cleaning and problem stays.any other idea's besides pulling and taking engine apart to check the heads and lifters.I've had one guy suggest to add trans fluid to oil to loosen valves,is that a good or bad idea.
COMMENT by mastertech6371 , January 01, 2012
the valves may be stuck in the guides. if they are, the head will have to come off. you can try the trans fluid but i doubt it will work Roy
ANSWER by patrick mannion , December 25, 2011
Cylinder leakage test would also be a valid test but of course is done static (engine off). We used to do what was called a running compression test years ago looking for bad cam lobes, it would be a good test too.