1999 Honda Civic SI Loss of compression Exhaust Valve?

JJIMENEZ8891

MEMBER
1999 HONDA CIVIC
132,000 MILES

1999 Honda civic loss of compression cyl 3 compression less that 15 psi wet test no real increase. Prssured with air, leaking towards exhaust, exhaust valve? If so I have previously been able to notice oil out of exhaust at start up and a also during high accleration could this have been why. And I now have extremly low compression in that cylinder and noticed that plug being the worse that last time I changed plugs now that I think about it.I recently replaced exhaust manifold with DC 4-1 headers and a aftermark cat and exhaust like as recent as a week previous to this any relations? I dont think so but please any imput helps. What could have caused it?

4 Replies

DJCL

MECHANIC
767 POSTS

I don't see how that could have caused this problem. Remove the head and check the valve. See why its not sealing. Just make shore nothing is loose under the valve cover.

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Monday, April 2nd, 2012 AT 11:35 AM

KHLOW2008

MECHANIC
41,815 POSTS

TYRy checking the valve clearances first. It they are too tight for the cylinder, readjust and retest compression. If compression does not increase, the valves are most likely burnt.

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Monday, April 2nd, 2012 AT 2:10 PM

JJIMENEZ8891

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29 POSTS

I will be removing the head this on friday so I will find out if it is a burnt valve issue. I sent another head for machine I will be swapping once its back. If I didint hear any noise knocking or anything is it more likly that it is burnt? If I have had a guide or seal going bad can that have been the cause little by little?

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Wednesday, April 4th, 2012 AT 3:02 AM

DJCL