younginwith66

so my c code 289 from a 1966 coupe is leaking oil from the valve covers and possibly and most likely the heads. my mechanic who is also a good buddy of mine said that i could possibly have blown a head gasket, because it appears to be leaking form there aswell.

so i did a compression check, and found that 6 of my cylinders were at 130~134 PSI. the other 2 were both at 141. they all held the compression too.
also, i am burning oil in the cylinders, because white smoke is coming out of the exhaust.

now, my question is, is that too low? am i going to need new pistons/piston rings etc...?

thank you

Starfury

A) 130-140psi is pretty solid for a compression test. Less than 10% variance between all cylinders is fine. No worries there.

B) If you blew a head gasket, you'd have much less compression than that. Also, it's almost unheard of to be leaking oil to the outside of the engine due to head gasket failure. The oil holes in the head are for drainage only, they're not pressurized.

C) Blue smoke would indicate burning oil. A little white steam is normal while the car is warming up, before it's hot enough to completely vaporize all of the water in the exhaust (water is a natural product of combustion). Lots of white smoke is coolant...but when is it smoking? Startup? All the time? What does it smell like? Coolant will have a sweet smell. Oil will have a thick...oily smell.

younginwith66

it smokes all the time, most on start up. but the smell, its not sweet, so its not coolant. its a combination of gas, and oil. im pretty sure on that.

but it never used to burn so much, i've seen it get worse. i've sort abused the engine for the few months that i have driven it. its seen a lot of WOT, and i think its beggining to break down

Starfury

Does it smoke more if you rap on the accelerator real quick? Sounds like you've got worn/broken valve seals, which wouldn't be uncommon for an older engine. Not an incredibly difficult fix, either, but a little time consuming.

MIL1ION

I'm curious.

Did you do this compression test with ALL the spark plugs removed at the time ?

younginwith66

im not sure whether if its more when i just smash the pedal really quickly, but i think that it is. and are valve seals cheap to fix?

i did it just removing one at a time. is that the best way?

i've also noticed quite a signifigant loss of power, do you think that there is any correlation between the problemms and the power loss?

Starfury

Valve seals are cheap, it's the labor that's kind of a pain. You need to either have an air compressor, or push a length of rope into each cylinder to keep the valves from dropping into the cylinders as you compress and remove the valve springs to get to the seals.

Ideally you want to remove all of the spark plugs while doing a compression test. This allows the engine to spin more freely and tends to get you a more accurate result. It will also make a compression leak between cylinders more obvious, although the results you have don't suggest any such leak, so don't worry about it.

You didn't mention any power loss before. When did that start? Is it all the time? Does the engine run rough?

What does your coolant look like? What about your oil?

younginwith66

the power loss started about 2 months ago. which is also when all my problems began. it used to run rough untill i changed the spark plugs and it runs smoother. thats because one of the plugs was bent so there wasnt a gap.

my coolant is lime green, and the oil. well what about it?