I recently bought a 86 iroc-z with a tuned port 350 and it developed a miss. I pulled the plugs and found the number 8 cylinder to be oil caked......(on the plug).....I guess my question is should i pull the head or the engine??? valve guides or rings??any help would be appreciated.......[>:]

 

sounds like a leak in the valve seal to me. pull the valve covers and have a look. might be an obvious leak, might not be. MOST likely will need to be changed.

 

How many miles are on it?

 

Do a compression test in comparison to the other cylinders it will indicate a ring problem if that is the problem.

 

That's a good idea griff. I'm trying to remember my Jeep, I think the rings were going in a few cylinders, so my plugs had some oil on them. But not heavy as described, just light.

 

it has around 140.....i raced my buddy in his mustang and asked him if it smoked when i went by him and he said no.so im pretty sure it doesnt smoke going down the road.......thats what doesnt make sense to me.....if it was rings it would smoke all the time right????? idid a compression test and the right bank was around 60 p.s.i.....by specs it should be around 100...the guy i got it from said it was a crate engine...roughly 30k on it

 

Does it smoke after it sits and then you start it leaking valve seals will have smoke at the start up.

 

60 psi is low strangly low for a 30000 mile engine, squirt some oil in the cylinder and do the compression test again, a leak down test could also be done. If the compression is signoficantly increased with the oil addition I would guess the rings are bad if not a valve sealing problem or head gasket problem. You got 140 psi in the oil soaked cylinder???

 

no the car reads 140k....the kid i bought it from was a moron....he said the engine was done around 30k and he never drove the car..i believe it is a true iroc but not sure.....the car needs some work. but what 86 for short money doesnt. the whole right bank including the oil soaked cylinder is 60 p.s.i.. i looked up the compression rating on all data and it said it should be around 100 p.s.i.. i just dont wanna pull the engine if i dont have to.

 

Do the oil squirt test and see what you have, does the engine have 110000 miles on it or 30000 miles?