help with blue smoke on deacceleration

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Mar 8, 2009 | 05:26 PM

ziggy123

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help with blue smoke on deacceleration

have blue smoke coming out of right side exaust only on deacceleration at rpm above 3500,any ideas on this no other smoke at any other time or start up,thanks for any input

Mar 8, 2009 | 05:28 PM

weimer20

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From: Ventura California

Valve guides / seals worn. JMO.

Mar 8, 2009 | 08:19 PM

7t2vette

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From: Toronto Ontario

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Quote:

Originally Posted by weimer20

Valve guides / seals worn. JMO.

That is the usual reason. There is a high vacuum created when the throttle is shut at higher rpm, and oil is sucked through the worn guides and or valve stem seals. I would still do a leakdown test to be sure it is not the rings.

Mar 8, 2009 | 08:47 PM

69small block

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From: punta gorda florida

Quote:

Originally Posted by 7t2vette

Mar 8, 2009 | 09:36 PM

BobbyC3

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Great advise

Mar 9, 2009 | 12:15 AM

blackcorvette1980

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From: Saint Louis MO

I did not see what year or tranny you have so this might not apply , but I had this on my 80 with the automatic tranny. The auto trannys have a vacuum switch that drops the gears down from 3 to 1 when you slowdown. I had this switch go out, and when I would let of the gas at higher speeds the stronger vacuum would suck tranny fluid, through this switch, back into the heads right above #8 and it would burn the tranny fluid, which caused blue smoke on the right side only. Just a thought.

Mar 9, 2009 | 02:56 PM

BigBlockTank

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From: Tucson AZ

Quote:

Originally Posted by blackcorvette1980

Is there some sort of vacuum modulator involved with this?

Mar 9, 2009 | 05:54 PM

blackcorvette1980

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From: Saint Louis MO

Quote:

Originally Posted by BigBlockTank

Is there some sort of vacuum modulator involved with this?

Yes, it was the vacuum modulator on the Turob 350 Tranny that was causing my problem. Had that replaced, and no more smoke, the others could be right, this is just another possable solution.