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Old 12-22-2008, 02:34 AM   #1
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Default Cloud of smoke, blue when first starting car in the morning

I just bought a 91 that supposedly overheated a few months ago, so headgasket and a valvejob was done (I have receipts from the previous owner), but it smokes heavily, I meaning really heavily in the morning, the smoke has a blue tint to it, and smells more like gasoline than anything else, but it's fine once the engine warms up.

The car passed the SMOG sniffer in CA test only station last week, so the cat should be working fine, of course the car was nice and warm. I am trying to figure it if it's just cold (we've had low 40's to mid 50's night temp) and high amounts of moisture causing this. Oh, and by the way, black liquid stuff sprays out the back when it's cold. I think it's a mixture of dirty exhaust and condensation, didn't feel oily.

This thing has headers and a aftermarket 2.25"(I think) catback exhaust
I haven't check the compression yet, I should check that to make sure it's not the headgasket, but if there was a valve job, I'm trying to think if it could be valve seals/guides for the blue smoke. A long time ago, my mom's camry had blue smoke early in the morning, and that was because of valve seals.

Any ideas what else it could be?
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Old 12-22-2008, 04:14 AM   #2
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Leak down test time.
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Old 12-22-2008, 05:32 AM   #3
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+1 on leakdown. If there's no turbo, it can only really be valve seals/guides or rings.
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Old 12-22-2008, 07:55 AM   #4
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If it only blows smoke when cold and goes away once hot i would say its valve stem seals or worse case the guides, if the head was done before as you say they may not have replace the seals.

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Old 12-23-2008, 05:10 AM   #5
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yep- valve stem seals. When they are worn, oil leaks down through them into the combustion chamber as it cools so then it gets burnt on startup.

Apparently there is a tool out there that works on some cars which allows the valves to be taken out without the head coming off. If you know a mechanic with this magic tool, it might save you some $$... maybe a myth though cos I don't actually know how it works.
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Old 12-23-2008, 05:15 AM   #6
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Its called rope... Stuff it down the spark plug hole so it fills the combustion chamber (TDC of course) and then you can remove the valve keepers and springs/retainers and swap the seals with the valves staying in place. This is an easy DIY job imo. Valve seals are an afternoon job if you have the tools and a little know how (or a book to tell you how).
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Old 12-23-2008, 05:26 AM   #7
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Haha
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Old 12-23-2008, 05:35 AM   #8
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But its true...
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Old 12-23-2008, 05:42 AM   #9
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in the old days we made a adapter out of a spark plug which alowed us to connect a air line to it, and fill the combustion chamber with compressed air,

Cheers
Dr.

Last edited by drbogg; 12-23-2008 at 05:56 AM.
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Old 12-23-2008, 06:19 AM   #10
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Then again, once youre that far along, its not much more work to go ahead and pull the head and have a valve job done, clean up some carbon, ect. More costly, but not much more work.
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Old 12-23-2008, 07:54 AM   #11
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Quote:
Originally Posted by NA6C-Guy View Post
Then again, once youre that far along, its not much more work to go ahead and pull the head and have a valve job done, clean up some carbon, ect. More costly, but not much more work.
I have to agree with NA6C-Guy here with this one your better to pull the head and do job proper that way you can check to see if there are any other problems with it.

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Old 01-06-2009, 01:11 AM   #12
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Might be the turbo oil seals.
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