is this a bad valve seal issue?

[natenut]

My car had a bad miss, pulled the plugs and found one black as tar. i did a compression test and the number 3 cylinder had 0 compression (the one with the black spark plug). i pulled the exhaust manifold off and found the following in the suspect cylinder:

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is this a bad valve seal? is this something i can fix myself or bring to a head place?

i have never really dove this far into a motor before. but its pretty fun so far, minus the knuckle juice I splashed all over the exhaust manifold/downpipe when i was removing it. no broken bolts (knock on wood)

thanks for any help

 

[trogador2005]

Definitely looks like a toast valve seal but I would say there's something else causing 0 compression like a burnt/bent valve.

Do a leakdown test to see exactly where the problem lies. that'll tell you what's wrong before you start pulling stuff apart!

 

[natenut]

Thanks, yeah did a leak down test and had like 60% loss. I couldn't really tell where the air was going, I was using a harbor freight leakdown tester and it only uses like 20 psi. It sounded like it was going up underneath the valve cover an coming out the oil fill hole.

also, there had been a lot of oil blasting out the oil filler cap and i noticed my dipstick had ejected itself.

It seems like there is some high pressure happening in the valvetrain/crankcase with oil blasting out of the valve cover gasket and coating the engine.

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[trogador2005]

yeah the air leaking into the crankcase point to piston rings. had the same thing happen to me. I had a bad PCV valve and had tons of crankcase pressure. it blew rings, valve seals, turbo seals, everything. since it looks like valve seals and rings in your case too you probably can't get away with just a head rebuild and you're looking at a full engine rebuild :/ which sucks i was just there last month and ended up doing everything myself.

 

[WES_393]

Bad valve stem seal will allow oil to leak out and boost/exhaust pressure to leak in. The result is smoking and high crankcase pressure, but it won't affect compression and usually won't foul plugs.

It's likely an issue within the cylinder itself. With that much oil and 0 compression, I'd say the piston/rings are seriously damaged. The excess crankcase pressure is a result of that cylinder being damaged.

 

[natenut]

thanks everyone. i'm just going to keep diving in and see where this goes.

 

[natenut]

looks like this thing had a timing belt break at some time and it damaged the exhaust valves. One was broken, the valve seals were totally blown out on the exhaust side. the cylinder looks ok, can still see the hone marks and no scratches you can feel with your fingernail. I found Jafromobile's channel on youtube and it has been a huge help going though the heads!!

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