White smoke at start-up
05-14-2003, 07:58 PM
#1
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White smoke at start-up- HELP SHOEBOX
Hey everyone,
I got the motor back in the T/A and have been driving it for about two weeks. Info on this motor can be found below in my sig. As of right now, I'm still running the stock programming. The motor puffs white smoke right after being started. As soon as it reaches operating temp it smokes no longer, and runs like a top. I have a A/F guage that I don't trust, but it seems to spend a lot of time in the lean, especially at idle. Any suggestions, or comments would be great. Thanks.
I got the motor back in the T/A and have been driving it for about two weeks. Info on this motor can be found below in my sig. As of right now, I'm still running the stock programming. The motor puffs white smoke right after being started. As soon as it reaches operating temp it smokes no longer, and runs like a top. I have a A/F guage that I don't trust, but it seems to spend a lot of time in the lean, especially at idle. Any suggestions, or comments would be great. Thanks.
Last edited by bad96firechikin; 05-14-2003 at 10:28 PM.
05-14-2003, 08:07 PM
#2
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you might have a super slow head gasket leak like when your engine cools down the water goes down into the cylinder. Then when you start it burns the water off then stops. While the engine is runnig it weaking so little that you can hardly tell it is burning water. Just my .02 cent
05-14-2003, 08:41 PM
#3
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I don't think I've ever heard of that happening before. Anyone else? I'm pretty concerned. Also, the engine doesn't make the kind of power I had been hoping for. I am running the stock intake and air box, and the stock throttle body as well. It pulls 15 inches of vacuum at idle. I do have a home ported MAF sensor.
05-14-2003, 08:46 PM
#4
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check two things..
look at the inside of your TB and see if its coated in oil. the hose going from the pass. valve cover to the side of the TB sometimes sucks up oil from the valvetrain, and gets into the intake. That's whats happening to me righ tnow.
Also, did you replace your valve stem seals? If you didn't, some oil might be seeping past the valves while your car is sitting overnight.. then when you start the car, the white smoke you see is the oil that's being burned off the tops of the pistons.
check those two. let me know what happens as well, because I have this same problem. (both of them). My solution? Its to get a deutsche breather filter for the valve cover, and get new valve stem seals.
good luck.
look at the inside of your TB and see if its coated in oil. the hose going from the pass. valve cover to the side of the TB sometimes sucks up oil from the valvetrain, and gets into the intake. That's whats happening to me righ tnow.
Also, did you replace your valve stem seals? If you didn't, some oil might be seeping past the valves while your car is sitting overnight.. then when you start the car, the white smoke you see is the oil that's being burned off the tops of the pistons.
check those two. let me know what happens as well, because I have this same problem. (both of them). My solution? Its to get a deutsche breather filter for the valve cover, and get new valve stem seals.
good luck.
05-14-2003, 09:31 PM
#5
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I can rule out the valve seals, because I ordered a brand new set of LT4 cylinder heads from GM Parts Direct. I did just run out and check, and after sticking my pinky in the tube to the throttle body, there is a little bit of oil in it. Why would it be doing this? It is a brand new engine (less than 1500 miles) with a new PCV valve, and new everything else? The oil is still clean, and until now, I doubted it was oil burning b/c it doesn't smell like oil. To me, it smells a little rich.
05-14-2003, 10:44 PM
#7
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I would be checking the smell of the smoke at startup to be sure it was not coolant. Keep a close check on the coolant level also.
A compression test could be something you might consider.
You should really get a tune for your mods.
A compression test could be something you might consider.
You should really get a tune for your mods.
05-14-2003, 10:48 PM
#8
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Thanks for the quick responce, you're awesome. It does smell a little like coolant, but like I said, as long as it is at operating temp, it does not do it. Also, how much do you think I stand to pick up with a CAI, 58mm TB (should I go 58mm, or 52mm?), and PCM For Less tuning?
05-14-2003, 10:54 PM
#10
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Originally posted by bad96firechikin
Thanks for the quick responce, you're awesome. It does smell a little like coolant, but like I said, as long as it is at operating temp, it does not do it. Also, how much do you think I stand to pick up with a CAI, 58mm TB (should I go 58mm, or 52mm?), and PCM For Less tuning?
Thanks for the quick responce, you're awesome. It does smell a little like coolant, but like I said, as long as it is at operating temp, it does not do it. Also, how much do you think I stand to pick up with a CAI, 58mm TB (should I go 58mm, or 52mm?), and PCM For Less tuning?
I'm one of the folks that thinks 58mm is a little big unless you are highly modified and can really flow the air. Just MHO. Mail order tuning is "ok" (and better than stock), but a dyno tune would be the best.
Try looking at your plugs, too. You might be able to detect a head gasket problem.
I don't like to guess at track gains because there are so many variables and I am not a person that goes to the track and gets to see how mods really affect times.
Last edited by shoebox; 05-14-2003 at 10:57 PM.
05-14-2003, 11:03 PM
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How would the plugs look to indicate a head gasket issue? Also, if it helps or means anything else, the exhaust smells like sulfur most of the time. At any rate, thanks for all your help. I've got to head to bed, but I'll check the post in the morning for your responce. Thanks Rob. - Brandon
05-14-2003, 11:27 PM
#12
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Originally posted by bad96firechikin
How would the plugs look to indicate a head gasket issue? Also, if it helps or means anything else, the exhaust smells like sulfur most of the time. At any rate, thanks for all your help. I've got to head to bed, but I'll check the post in the morning for your responce. Thanks Rob. - Brandon
How would the plugs look to indicate a head gasket issue? Also, if it helps or means anything else, the exhaust smells like sulfur most of the time. At any rate, thanks for all your help. I've got to head to bed, but I'll check the post in the morning for your responce. Thanks Rob. - Brandon
05-14-2003, 11:56 PM
#13
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A bit of oil in the TB is totally normal.. I wouldn't worry about it.
I will say that you do have a problem if your car is smoking. Blue smoke indicates oil consumption while WHITE smoke indicates water/coolant consumption.
I'd say you have a bad headgasket. If you let the car sit then the coolant will slowly flow into one or more chambers and puddle, then when you start the car up it burns it off in a puff of white smoke.
I agree with shoebox, you should have a compression test done and check the plugs - the faulty ones just look "different".. cleaner or newer kinda.. it's hard to describe but you should be able to tell.
Anyways, watch that coolant level, I'd say you are definately burning coolant probably through a blown headgasket.
Sorry for the bad news
I will say that you do have a problem if your car is smoking. Blue smoke indicates oil consumption while WHITE smoke indicates water/coolant consumption.
I'd say you have a bad headgasket. If you let the car sit then the coolant will slowly flow into one or more chambers and puddle, then when you start the car up it burns it off in a puff of white smoke.
I agree with shoebox, you should have a compression test done and check the plugs - the faulty ones just look "different".. cleaner or newer kinda.. it's hard to describe but you should be able to tell.
Anyways, watch that coolant level, I'd say you are definately burning coolant probably through a blown headgasket.
Sorry for the bad news
05-15-2003, 09:33 AM
#14
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I dun wanna tear my motor down again!!! 
Oh well....better than a ring seal problem, or something else. I'm about to go out and check the plugs. Thanks for the help guys. If anyone else has any thoughts or suggestions I'm open to them.
Oh well....better than a ring seal problem, or something else. I'm about to go out and check the plugs. Thanks for the help guys. If anyone else has any thoughts or suggestions I'm open to them.
05-15-2003, 04:13 PM
#15
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When my head gasket went it did not smoke when running. The coolant level dropped quite slowly and all of the leaking coolant was getting burnt because my oil was clean with no froth. A low coolant light came on which was my first warning. when I pressure tested the cooling system it forced the issue and filled one of my cylinders with coolant and my engine hydrolocked then I had coolant in the oil.
Why your engine is sluggish may be due to a fouled oxygen sensor from burning coolant?? (just a thought anyone have any in put on this??)
I would check the following
1) I would pressure test the cooling system with the engine cool.
2) Check the oil for foam or milky color
3) Check coolant level and monitor closely
4) Like someone else stated start the engine cold and smell the exhaust. I would have someone else start the car and be sniffing out the exhaust and seeing if any water comes out the tail pipe.
Why your engine is sluggish may be due to a fouled oxygen sensor from burning coolant?? (just a thought anyone have any in put on this??)
I would check the following
1) I would pressure test the cooling system with the engine cool.
2) Check the oil for foam or milky color
3) Check coolant level and monitor closely
4) Like someone else stated start the engine cold and smell the exhaust. I would have someone else start the car and be sniffing out the exhaust and seeing if any water comes out the tail pipe.