smoke at start up

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May 6, 2006 | 07:23 AM

tigmaned

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From: crofton maryland

smoke at start up

was trying to get some info on some i would say grayish blue smoke at some start ups. not all the time mostly after she warmed up and sat a few minutes. i am kind of thinking injector leak down or oil blow by? i don't think head gasket, since ever since i have had my 1986, L-98 just hit 90K, it never runs hot, never notice water in oil, or sweet smell at exhaust.
Thanks for any help you can give.

May 6, 2006 | 08:35 AM

redrose

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From: backwoods upstate ny

probably not an injector problem, but good idea to check first since its so easy...harber fright has a fuel pressure test kit on sale now for $8 if you don't already have a tester.
most likely valve guide seals or worn valve guides....most oem aluminum heads develop loose guides at about 50k miles cause the factory didnt use any guide other than the aluminum head itself--have an auto machine shop put in bronze guides and grind the valves/seats...valve seals harden due to heat/age and don't stop oil--might help if you just put new ones on, but at 90k--not too promising

May 6, 2006 | 09:07 AM

AGENT 86

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From: Summerland B.C. Canada

Good chance the valve seals are done. New seals cured mine.

Quote:

Originally Posted by redrose

most oem aluminum heads develop loose guides at about 50k miles cause the factory didnt use any guide other than the aluminum head itself

Are you sure about that. Can't see aluminum guides lasting long. My factory aluminum heads came with pressed in guides. I recently rebuilt my heads and had the shop install bronze liners into the guides. Better than new now.

May 6, 2006 | 09:13 AM

JackDidley

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From: Database Error Indiana

86 is correct. The seals were leaking on my 87 at 35k miles. Not realy a problem. The guides are pressed in steel. I replaced the seals before I used the heads on my Nova.

May 6, 2006 | 09:24 AM

CMYC4GO

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From: Oklahoma City Oklahoma

Quote:

Originally Posted by AGENT 86

Good chance the valve seals are done. New seals cured mine.

Just the nature of a SBC. You might also check to see if your drain backs are clogged.

May 6, 2006 | 09:50 AM

redrose

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From: backwoods upstate ny

Quote:

Originally Posted by AGENT 86

Good chance the valve seals are done. New seals cured mine.

Are you sure about that. Can't see aluminum guides lasting long. My factory aluminum heads came with pressed in guides. I recently rebuilt my heads and had the shop install bronze liners into the guides. Better than new now.

nope, not sure...thats what my cylinder head wizard told me--i don't even disassemble em, just toss em on his ''dirty parts'' bench and pick em up from the ''clean'' side after he does his ''magic''...but bronze guides are always an improvement in the way even low mile engines run...on my rail drag car, with ''zoomie'' pipes, at night you could see the exhaust color change from blue to orange after about 20 passes,and the e.t.'s started to fall a bit at the same time--fresh heads from the wizard brought the pretty blue right back.

gotta visit the man monday, i'll ask

Last edited by redrose; May 6, 2006 at 09:53 AM.

May 6, 2006 | 10:09 AM

tigmaned

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From: crofton maryland

yeah i was thinking typical chevy too. like rear main leaks!! i have a early 86 with cast iron heads.
last time i did a fuel pressure check i was right at 39psi which is right for L-98, but after i shut the engine off i got a pretty fast drop in presssure to about 25psi and then it stayed like that a while.

May 6, 2006 | 11:11 AM

87 rag

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From: Port McNicoll Ontario

I'm going to go with the crowd on this one and say valve seals.
I just replaced mine and it cured the problem.
They say white smoke=water, black smoke =fuel and blue smoke =oil.
If you have bluish smoke that says oil. When I replaced mine I couldn't even tell the old ones were bad but the smoke went away. The little o-rings on the valves crumbled when I touched them though.