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Discussion Starter #1
Ok my 280zxt has just started to smoke, it always had a little, very little, black smoke but that was from running it slightly rich. Now whenever i get on it and let off the gas it smokes quite a bit when on its way down just before it drops to idle and for about the first second or two of idle it smokes as well, after that nothing no smoke at idle or when reving the engine. the smoke is white and doesnt smell "sweet" like antifreeze so i think it might be oil but from rings or the turbo, this all started happening whithin a week or two and i thought rings took time and slowly started smoking, and power is still great. thanks for any ideas.



blake
 

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Hi Blake-----------The turbo may not be the problem. If you have an automatic transmission in your car, check the modulator valve. It is located in the line that runs from the trans to the intake manifold. Many times this valve will fail and cause the white smoke that you are seeing. Bad turbos usually result in blue smoke, much like worn rings.

Roadman
 

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sorry i should have said it was a five speed, i searched the archives and found that auto modulator thing problem all over.
 

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hi blake. to me it sounds like your valve guides are worn out. the smoke when you let off of the gas is a common sign of worn valve guides. your valve guide wear out because the rockers dont push down perfectly straight on the on the valves, they rock(hince the name rockers). after thousands of miles of driving this tends to create a wedge shaped gap between the valve guide and valve stem. a pool of oil seeps down in the worn area and when you let off of the gas it creates and enormous vacuum that sucks the oil through the valve guides into your cylinders, so you get smoke when you let off of the gas. they can be replaced, it's not difficult if you get the parts. i've done it on lawn mower engines before, same principle and same tools are involved. it's not expensive if you do it yourself but it'll cost a lot if you have it done.

that's my opinion at least. i learned this from a man who's been teaching power mechanics for 30 years
 

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thanks Roadman and Pat, the valve guide sounds like its worth a shot. And by valve guide do you mean the rubber seal or the actula metal tube that the valve is inside of? i have had a head rebuild and i did it all but the machine work (on a na zx) so i know a bit about the heads.
blake
 
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