oneludesol

Car in signature developed a dead #2 miss out of the blue, has fuel, has spark, has good compression, has less than 3% leakdown... I found that the #2 exhaust valve lash was zero, no feeler would fit whatsoever. The others were within spec. I tried to loosen the tight one, and backed the screw until it stopped, and still, no clearance!? WTF bad valve seat or something?

oneludesol

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5thgen

the cam lobe wasn't pushing the rocker when you measured it, was it?

I don't know....it doesn't make sense to me because compression/leakdown came out good. Maybe try taking the manifold off and looking down the port.

oneludesol

I honestly wouldn't have thought of looking through the exhaust... mani has to come off for the head to come out anyway, so ill have a peek. Thanks.

anyone else?

5thgen

You could take a plug out and shine light through the spark plug hole and watch through the port while you turn the motor. If its sealing like you say though, I doubt you'll see light.

ludeboy22

Its possible but IMO if everythings in spec I'd pull the head to further inspect.
i had an intermantent missfire and the next day it was a dead cylinder turned out to be the valves

thank god the no piston damage was done