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Smoke when in gear and let off the gas

There was a few boss's running Saturday, one car started smoking on the track but only when he was in gear heavy on the gas but let off for a corner. It was burning oil, what mechanical issue would cause a small plume out of the left pipe when off the gas coming down from speed? Trying to help this guy out. Great car, good guy, member at Spring Mtn. Anyone?
 
1,022
97
Exp. Type
HPDE
Exp. Level
10-20 Years
Texas
GTMikey said:
There was a few boss's running Saturday, one car started smoking on the track but only when he was in gear heavy on the gas but let off for a corner. It was burning oil, what mechanical issue would cause a small plume out of the left pipe when off the gas coming down from speed? Trying to help this guy out. Great car, good guy, member at Spring Mtn. Anyone?

What color was the smoke? Black is unburned fuel and blue is oil. If the car is tuned and it's a rich tune it might just be unburned fuel when he gets off the throttle. I avoid aftermarket tunes like the plague. I have seen too many people ruin motors. Just my .02
 

unrealford

Mustang owner since 84
521
0
If it was out of one side alot more distinctively I would say definitely a issue to check out.
 

TMSBOSS

Spending my pension on car parts and track fees.
6,221
3,206
Exp. Type
HPDE
Exp. Level
5-10 Years
Illinois
Smoke on deceleration is a sign of valve seals leaking. Unusual on a newer car.

When the car is slowing down, throttle closed, intake vacuum goes up and oil is drawn past the valve seals.

Could be this. Is the smoke blue or White?
 

JScheier

Too Hot for the Boss!
GTMikey said:
Smoke was white and yes, running Trackey.
Mike

I've had similar instances in mine with the Trackey... but usually only off track. It appears that lopey-idle may be the cause as turning it off (hold the 'off' button on the wheel while starting and for 5 seconds after, should sweep the gauges) seems to have remedied that.

My guess is that the aggressive overlap of the cams for the idle is causing the issue under race / track conditions.

I could be wrong (it's happened before)... but turning off idle seems to have worked for me. We'll see if it works at Pueblo this weekend as that track seems to generate more 'smoke' after a session than any of the others (more high-rpm, right at the limiter sections).
 
1,437
352
Mikey for reference your car was sporting blue smoke at mach speeds at WOT. :p

BTW less than 2 months till Tahoe! 8)
 
1,437
352
GTMikey said:
While we are at it, what's blue smoke mean? I know it's not good

It was either sucking some oil in somewhere and burning it, or it was trying to consume the known universe through the intake tract. Based on the insane amount of fun we were having, and the fastest tour of CA, AZ, and NV known to man, I vote for the latter. :D


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