Dragonfly Posted October 30, 2002 Share Posted October 30, 2002 I pulled my spark plugs the other day and all of them looked good except #4 which appeared to be oil fouled. I ran a static compression test and #4 was 165#'s while the others varied from 173-179#'s. I do not have a leak down tester so I put #4 to TDC and pressurized it to 70psi and I could hear air escaping past the rings (none out of the intake or exhaust). I squirted oil into #4 and checked the compression again and it still read 165, I checked three more times and each time it read 165. I do not understand how I can hear air getting past the rings but adding oil did not raise the compression, am I missing something? Dragonfly Quote Link to comment Share on other sites More sharing options...
deMideon Posted October 30, 2002 Share Posted October 30, 2002 Probably a head gasket or burned valve. Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 30, 2002 Share Posted October 30, 2002 You will hear air past the rings for the simple reason that their is a gap in each set. 165/179*100=92.178 which is ~8% which is not too bad from highest to lowest. Not enough to have a damaged valve or rings IMO, (and evidenced by your compression check) so that leaves the easiest and cheapest problem. Bad valve stem seal. Probably time to do them all. Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted October 30, 2002 Author Share Posted October 30, 2002 Mike I hope you are correct with your assesment, I will check them tonight when I get home. Demidion I hope you are incorrect but if the simpler solutions do not pan out I will start checking the ones I don't want to hear. Dragonfly Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted October 31, 2002 Author Share Posted October 31, 2002 Last night I pulled the springs off the valves for #4 cyl. and the seals were fine, what I found though is that the valve guide for the exhaust valve is worn out and the valve has enough movement that I can easily feel it. Looks like the head is going to have to come off even though I had hoped not. Dragonfly Quote Link to comment Share on other sites More sharing options...
Tim240z Posted October 31, 2002 Share Posted October 31, 2002 Oh well, Miles.... Good opportunity to give the head a good 'going through'...port and polish, new guides, new seals, new seats etc.... etc.... Just think...at least it's easier than a V8!! Tim Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted October 31, 2002 Author Share Posted October 31, 2002 Yea its going to get everything cleaned up etc. it has already been ported and polished. To make a long story short the head should have had new guides also but they went into a head that was bad and I missed having them put into this head. While I have it off I am going to have the head shaved a little to bump up my compression. Dragonfly Quote Link to comment Share on other sites More sharing options...
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