White smoke on startup
Thread Starter
Heel & Toe
Joined: Apr 2003
Posts: 22
Likes: 0
From: DeSoto KS
White smoke on startup
On occasion I will start it up and some white smokes comes out of the exhaust. It isn't all the time, but it seems to have a greater chance of occuring when the engine has been sitting for a time (usually over night)...
Any ideas what this is?
Thanks in advance,
Steve
Any ideas what this is?
Thanks in advance,
Steve
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: White smoke on startup (Steve_88)
You have a head gasket leak and the white smoke is vaporized coolant. Smell the white smoke and it will smell odd, not describeable, but it definetely will not be burned oil or unburned gas.
Burning Brakes
Joined: Jun 2003
Posts: 1,229
Likes: 1
Re: White smoke on startup (jfb)
I'm not an expert, but I've heard a lot about valve seals on a 350 V8 will do that... and will only do it when the engine is cold. Oil leaks down the valve seal over night and when you turn the car on, the oil will burn and make white smoke.
If you want to make certain its not coolant because of the head gastket, I would check the oil and make certain there is no coolant mixed up with the oil, or do a Rad presure test to see if the coulant will leaks out the sides of the engine and/or have a compresion test done.
If you ask me.. its probably just your valve seals. I've heard A LOT of people say that about 350 in general.
Just my opinnion
[Modified by TheStef, 10:48 AM 9/23/2003]
If you want to make certain its not coolant because of the head gastket, I would check the oil and make certain there is no coolant mixed up with the oil, or do a Rad presure test to see if the coulant will leaks out the sides of the engine and/or have a compresion test done.
If you ask me.. its probably just your valve seals. I've heard A LOT of people say that about 350 in general.
Just my opinnion
[Modified by TheStef, 10:48 AM 9/23/2003]
Thread Starter
Heel & Toe
Joined: Apr 2003
Posts: 22
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From: DeSoto KS
Re: White smoke on startup (jfb)
Actually I think it does smell a bit like gas when I start it up... Are there any other signs that the head gasket would be leaking? I will see if I can smell it when I start it up again...
I just did an oil change over the weekend and the oil looked fine... About a week ago I had the intake gaskets redone because they were leaking coolant...
Thanks!
Steve
[Modified by Steve_88, 4:48 PM 9/23/2003]
I just did an oil change over the weekend and the oil looked fine... About a week ago I had the intake gaskets redone because they were leaking coolant...
Thanks!
Steve
[Modified by Steve_88, 4:48 PM 9/23/2003]
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: White smoke on startup (Steve_88)
Depends on how much smoke there is and whether its missing or not.
If its just a little, its probably condensation in the exhaust, especially when you let it sit outside overnight and then start it.
If its missing, or your temperatures are not where they should be, it could be a head gasket.
If its just a little, its probably condensation in the exhaust, especially when you let it sit outside overnight and then start it.
If its missing, or your temperatures are not where they should be, it could be a head gasket.
Thread Starter
Heel & Toe
Joined: Apr 2003
Posts: 22
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From: DeSoto KS
Re: White smoke on startup (vader86)
The temps never seem to get that high, I think if I am driving in town it will get up to around 210, but usually it stays around 190 on the highway.
Steve
Steve
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: White smoke on startup (Steve_88)
Well I believe you can wait a little while, since you recently changed oil, and then at your next oil change, be sure to look at the old oil.
I think its just condensation. But do listen for any noises in the motor that might indicate missing and your oil/coolant temps. Usually temps will skyrocket once you blow a head gasket. Also, it shouldnt make any smoke after its had a couple minutes.
I think its just condensation. But do listen for any noises in the motor that might indicate missing and your oil/coolant temps. Usually temps will skyrocket once you blow a head gasket. Also, it shouldnt make any smoke after its had a couple minutes.
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: White smoke on startup (vader86)
Another, albeit highly unlikely, cause could be a leaky injector....but white smoke is usually just moisture. Head gasket or just normal condensation. Monitor coolant level, oil condition and eng temps. I had the occasional puff of smoke a couple years back but it hasn't done it in a long time now, and I attribute that to the known valve seal leak that the LT1 is known to suffer from.
Keep us all posted. :seeya
Keep us all posted. :seeya
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Thread Starter
Heel & Toe
Joined: Apr 2003
Posts: 22
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From: DeSoto KS
Re: White smoke on startup (vader86)
I still have the oil from my last change, it looks okay to me, but I was told by a mechanic that you can't always tell with today's oil if there is any coolant in it. I thought if there was coolant in it it would turn white? This stuff was defenitly black and had a pretty good consistancy... How should I test the oil?
I don't know if this matters or not, but both of my mufflers are still on the car, but they are completely rusted through and actually they arn't really attached to the pipes any more... Could this increase the moisture content in the exhaust?
I don't think the car is missing at all, it actually runs great, and the smoke goes away a few seconds after starting...
Thanks so much for your help!
Steve
I don't know if this matters or not, but both of my mufflers are still on the car, but they are completely rusted through and actually they arn't really attached to the pipes any more... Could this increase the moisture content in the exhaust?
I don't think the car is missing at all, it actually runs great, and the smoke goes away a few seconds after starting...
Thanks so much for your help!
Steve
Team Owner
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: White smoke on startup (Steve_88)
Yeah if you have rusted pipes, there are more places for humid air to settle.
But, there are places where you can send the oil for testing, i just dont know the names.
But, there are places where you can send the oil for testing, i just dont know the names.
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
Re: White smoke on startup (vader86)
I'm with Vader here. With the cool nights we are starting to have, condensation will build up in the exhaust as it cools and give you a short puff of white smoke on start as the exhaust gas heats up the pipes. Just keep an eye on the coolant level and the smoke. If the level decreases and the amount of smoke increases I would look at head gaskets.
Drifting
Joined: Mar 2000
Posts: 1,630
Likes: 1
From: Woodstock GA
Re: White smoke on startup (Steve_88)
Are you sure it's white smoke? The reason being leaking valve guides seals will give you a light blue smoke on start up after the car sits over night or so. A coolant leak into the intake or combustion chamber can give you white smove on start up but sometimes not right at first but a few seconds later and the smoke would have a sweet smell. Also a failing ECM can give you white smoke on start up if you get a internal short that turns the injectors on full, so much gas enters the engine it is unable to burn so insteel of black smoke like one would suspect it comes out white. Now in many cases when this happens you will also have problems starting the car manbe extended crank and you would also probably smell gas on the oil dip stick. But also a lot of short trips in humid climits can give you a lot of condensation build up in the exh system and this will give you white smoke sfter start up but not have a smell.
David Fulcher
David Fulcher
Melting Slicks
Joined: Aug 2000
Posts: 2,505
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From: Nashua NH
Re: White smoke on startup (Steve_88)
My old GTA trans am did this also. It had the tuned port 350 in it. It was valve stem seals. That sounds like what is wrong with yours. If your oil looks good chances are the head gaskets are fine
Le Mans Master
Joined: Aug 2000
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From: Airport Cruise-in 1 Veteran Airport Cruise-in 2 Veteran
Cruise-In II Veteran
Re: White smoke on startup (David-F)
Also a failing ECM can give you white smoke on start up if you get a internal short that turns the injectors on full, so much gas enters the engine it is unable to burn so insteel of black smoke like one would suspect it comes out white.
I have a burned plug wire and it was touching the header. The combustion chamber would fill w/ gas but no spark to burn it. I had white smoke puffing out the tail pipes.
Le Mans Master
Joined: Aug 2003
Posts: 9,884
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From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
Re: White smoke on startup (Steve_88)
87-91 Service Bulliten: Tail pipe smoke at startup: #328
Some owners may comment on a puff of blue or bluish white tailpipe smoke at startup
Cause: Oil leaking past valve stem seals and being deposited on exhaust valve(s)
Correction: new valve stem seal kit PN 12511890 - kit includes new umbrella seal with a viton insert for the exhaust valve stem:
Maybe this helps or now...
Some owners may comment on a puff of blue or bluish white tailpipe smoke at startup
Cause: Oil leaking past valve stem seals and being deposited on exhaust valve(s)
Correction: new valve stem seal kit PN 12511890 - kit includes new umbrella seal with a viton insert for the exhaust valve stem:
Maybe this helps or now...
Melting Slicks
Joined: Dec 2001
Posts: 2,437
Likes: 1
From: Gainesville Fl
Re: White smoke on startup (vinnies87)
mine does the same thing and my mechanic says its the valve seals. nohting to worry about though. unless it continues while you drive it and not just on a cold startup
Thread Starter
Heel & Toe
Joined: Apr 2003
Posts: 22
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From: DeSoto KS
Re: White smoke on startup (1996man)
Wow, thanks for all the input!
It looks white to me, and I can't really smell much in the exhaust, but there is a lingering gas smell from the car it's self, not the exhaust. The car has 160,000 miles on it and still seems to run great, so i think I will just leave it until I have it completely rebuilt.
Again, thanks for all the input!
Steve
It looks white to me, and I can't really smell much in the exhaust, but there is a lingering gas smell from the car it's self, not the exhaust. The car has 160,000 miles on it and still seems to run great, so i think I will just leave it until I have it completely rebuilt.
Again, thanks for all the input!
Steve
Drifting
Joined: Mar 2000
Posts: 1,630
Likes: 1
From: Woodstock GA
Re: White smoke on startup (Steve_88)
Check in front of the left rear tire by the park brake cable and frame pinch weld you will find a small rubber hose connecting two steel lines that is for fuel tank vent the hose comes apart over time and can give you a strong gas smell, check it out it could be the cause of the gas smell.
David Fulcher
David Fulcher
