I have a 99 and its had a SES code for a while now and its been getting progressivly worse. Misfire on #4 cylinder.I did the usual tune up which didnt help. I ran a compression check and all cylinders other than #4 were 170-180. #4 was 125. I shot some oil in the cylinder and tried it again , didnt move much. Question is where/what should I look at first? It has 123K on it.
Low compression #4 cylinder
- Thread starter 1slohoe
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
SunlitComet
OBS Jedi-Do Good
That forth cylinder is below the threshhold difference compared to the others but if adding a little oil did not improve it then you can probably eliminate a ring problem. That leaves you with a valve or head gasket problem. Can you do a leakdown test? This will help narrow it down short of taking the head off. Actually if either of those problems exist its got to come off anyway so go for it and have a machine shop inspect your head if you don't find a bad gasket.
Dlong30
Member
i agree... most likely a valve. a gasket would usually affect more than one cylinder. guess its time to pull the head!
retorq
Full Access Member
Only if scorched between the two adjacent cylinders ... I've sent them pop outwards, inwards and even into the water passages. A leak down test should tell you where it's leaking too ...
