Metraman

I was doing some testing yesterday at an airport a few of us rented and noticed in the rear mirror a large cloud of white smoke at 140 mph in sixth gear. So i tried it again and at about 100 the smoke starts. I did some other tests and then tried it in forth gear and got no smoke. Anyone got an idea what the hecks going on? My tips definitely had some water coming out. Drove home 50 miles with no smoke and tips were totally dry?
Thanks

OliverM5

White smoke is never a good sign, means water is coming into the motor somehow. My guess is that in sixth gear, the load is heavier on the motor and therefore causing the issue. I wouldn't drive it until you had it checked out by a pro shop....

zeshawn

why did you say water, why not oil? is you're car overfilled?

Metraman

Stepped on it today a couple of times no white ( White is water ) runs great sure is strange.

68sixspeed

any chance the intertcooler is leaking in the intake? Otherwise I'd think head gasket, cracked head as typical causes...

Metraman

I would think I'd have smoke more often I don't have much water missing.

DYNAMIC RON

Condensation? Yesterday morning i backed my ZR1 out of the garage. The tthe temp was about 47 deg here in Michigan. I let it warm up while i was locking up and observed water dripping from the exhaust tips which turned into white smoke in a few minutes. I didn't pay attention behind the car as i drove but only got up to 45 mph. I can tell you it takes 10 miles for the oil to get to 190 degrees at these speeds. If you are not loseing coolant or there is not coolant in the oil, power loss or running rough i think that condensation is what you saw. After some hard running for a good period of time all of the moisture should burn out. When the hot exhaust system cools it will happen again.

Metraman

The car was plenty hot it had been running for about 3 hours. I've sent a note to a couple of engineers at GM I know they may have a idea.

Mfahhad

i dont think its water

my best guess is oil

have it checked out

Xwet

You can remove a few spark plugs and see if there is any oil on the plug seats. If using oil the oil collects on the seat.

kenedds

Isn't burning oil from the exhaust a bluish, white smoke? Water alone would be just white, like steam!

LEAVINU

At WOT and triple digit speeds I'd definitely be concerned. Let us know what your GM friends come back with.

Metraman

GM has contacted me they are happy to have a look. Their planning to take it to the test facality at their proving grounds. They wanted me to know they would be checking EVERYTHING I told them have at it.

petefias

It is great that GM took a proactive stand at addressing your issue. Will be interesting to see what they find. Please come back to tell us how it turns out.

DDSLT5

Sounds like your car is fine.

1. Why were you at WOT in 6th at 140? Why not 4th?

2. How do you know the 'smoke' was coming from the exhaust? Could it have been something on the road that the tires were kicking up?

If you had a blown head gasket or cracked head, you'd either have coolant in the oil (milky appearance) or you would be pushing pressure into the cooling system, overflowing the system.

Since neither of these are occuring, I'm guessing your car is fine.

Metraman

How about a leak at the intercooler. It can't be to fine when the coolant level is dropping?

range96

Have you checked for water loss in the supercharger cooling system?

Metraman

Isn't it all the same coolant the over flow is down an inch.

range96

No, not at all.

See this thread:

http://forums.corvetteforum.com/c6-c...tercooler.html

Metraman

Sounds like it's still the same coolant?

There's an electric pump in the system that circulates the fluid from the radiator through the intercooler, and you need a Tech 2 to command the electric pump to run to properly purge the system when servicing it.
Gm going to have to figure it out.