Hey guys,

My best friend's mom is looking at buying a 2004 Corvette Convertible with 11,000 miles. I drove it at the dealer today and noticed while the car was stopped and idling it would hesitate slightly. It wasn't that bad and the tach needle was barely moving but I could definitely feel it. It did this both with the A/C on and off. The sales guy it's normal b/c the car has such a 'big' engine (it's the base 5.7L) which I think is BS. To all you Vette owners out there... is this normal? Is it b/c it's a convertible and doesn't have the added stability of a roof?

If it isn't I'm thinking it may be a vacuum hose, O2 sensor, bad fuel or spark plugs/wires.

I appreciate any advice!

Thanks,
Mark

 

I have an 03 with 18,000 miles on it an it burbles a little while idling at stops. Always has.

 

A tiny bit.

 

No, it's not normal. GM has a TSB out for this condition. It involves installing an iridium spark plug with a smaller gap: .040".

The iridium part is irrelevant to the repair. It's that gap that's important here. Install any correct replacement spark plug and close the gap to .040". I've been doing this on Corvette's since ~2003, long before the TSB.

The TSB addresses all Gen III engines, but for whatever reason the Corvette engine mounts/chassis better transmit the instability to the driver.

 

I have on 04 with 35000 miles, and I have not noticed it on mine.

 

Mine doesn't do it anywhere near enough to warrant changing plugs or gaps. Some people are just too picky in my opinion.