924RACR Posted July 22, 2004 Share Posted July 22, 2004 Figured this might perhaps be the best place to get a technically knowledgeable response. I am having a continuing problem blowing out the front seal in my '86 Suburban with a 350, very very annoying and persistent. I rebuilt the motor last fall, and put a standard dress-up kit on it (mainly for new valve covers, but included a new timing cover). I have bad problems with the front seal leaking then... figured out that the damper was grooved (165kmi engine), so replaced it and put in a new front seal and oil pan gasket while doing so. It has again begun to leak after towing long enough to really get everything good and warm and all (on the highway as opposed to city streets). I'm still left wondering what the heck could be the reason why I continue to have oil coming out the front seal when the engine's working hard. It also appears to maybe be leaking a bit at the front (only) of the pan. If I back off, slow down 5-10 mph (to 65 instead of 70-75), the smoking goes away (oil drips on exhaust at that point). Could it be that the timing cover is the key to it all? Should I put the old one back in? Or am I completely missing the root cause of all the leaks? Please help this poor Chevy newbie get to Mid-O in August!!! Thanks... Quote Link to comment Share on other sites More sharing options...
Micks 41 Posted July 22, 2004 Share Posted July 22, 2004 This may sound like a stupid question but do you have breathers in both valve covers? It sounds like you might have high crankcase pressure. Quote Link to comment Share on other sites More sharing options...
924RACR Posted July 22, 2004 Author Share Posted July 22, 2004 Not stupid at all; breather in one valve cover, PCV in the other. The issue of crank pressure was raised here (@ work, by knowledgeable techs), but I checked and the PCV valve is sucking with the engine running. One other question raised was maybe the chrome on the timing cover is interfering with the seal; suggestion was raised to remove the seal, wire-wheel off chrome in the seal area, and reinstall seal (preferably a new one of course) with a bit of RTV. Thanks... any other things to check? Quote Link to comment Share on other sites More sharing options...
Frank Corkran Posted July 22, 2004 Share Posted July 22, 2004 I'd second the chrome front cover suggestion. Chrome Chevy T-stat housings are notorious for leaking if you don't file off the chrome from the gasket surface, so maybe the same is true for the front cover. Quote Link to comment Share on other sites More sharing options...
Keith Posted July 22, 2004 Share Posted July 22, 2004 http://frrax.com/rrforum/index.php?act=ST&f=9&t=1865&hl=&s=5853c2147b6d50318c101c2cc80c6eb7 Quote Link to comment Share on other sites More sharing options...
924RACR Posted July 23, 2004 Author Share Posted July 23, 2004 Thanks guys! I'll have to see what I can do with that cover... the front of the pan gasket itself was suggested as a possible alternate source of the oil too, since that area is apparently problematic too. I do have to point out that, with the recent rebuild and minimal miles, I think the liklihood of it being bad rings should be minimal... I hope! Thanks... Quote Link to comment Share on other sites More sharing options...
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