corvettesforevor

So I got a 1993 corvette a couple days ago. I didn't have time to check all the fluids yet so I did today. The oil was a bit low so I added some. The coolant was also a bit low in the overflow tank so I added some. All seemed fine then. Next I turned on the car to pull it out of the garage. It started idling super high, like at 2500. Alot of smoke was coming out of the exhaust too. I drove around the block to see if it would stop. But no, it was idling even higher. It would jerk after each shift because of the so high idle. When I was almost home it was idling at 3500 Rpm! I pulled it into the garage so I could check under the hood. I turned it off and looked. Nothing seemed out of the ordinary. The coolant overflow tank was making a chug-alug sound but I don't think that has anything to do with it. I closed the hood and started it again.... Now everything is normal.. Idles at 700rpm, drove fine... what the heck happened?

Before this I had my car jacked up on one side just so I could take a peek underneath to check out the exhaust setup, I didn't touch anything though. I'm just including that for additional info, not that it would cause this weird event.

DanielRicany

What color was the smoke? If there was chuggling in the over flow tank, it means it is getting very hot to the point where the antifreeze or water is boiling.

If I had to guess I'd say there's an intermittent head gasket leak if the smoke was white.

Not sure about your high idle though.

JrRifleCoach

That is weird.
Check the codes?

corvettesforevor

It was just white as far as I could tell. It didnt stink to bad either

Paul Workman

Definitely some "mixed messages" there, huh? One minute there's head gasket clues as well as vacuum "leak" clues. But, upon start up, back to normal. If we're NOT being scammed, I guess we'd start by breaking it down, piece at a time - perhaps with inspecting the plugs and/or doing a compression check (gasket leak).

C409

..... It might be time to lube up throttle body plates and shaft ... I usually do mine about twice a year ... pull the intake hose off and spray away with your favorite lubricant while working the throttle plates open and closed ... I use silicone spray and don't recommend WD40 ..... By The Way ... there is NO such thing as an intermittent head gasket leak .......... Another possibility is a sticking or intermittently operating IAC valve ... you can check IAC counts with a scanner ... but I would unplug the connector and plug it back in a few times to clean up the contacts ..........