VforVETTE

1991 Corvette, automatic transmission.

Just recently my corvette has been acting a little weird. It seems as though it is revving much more than usual.
This video (which is taken quite terribly) shows a little what I am talking about.


From what I have observed:
4000+ RPM at 70+ mph
4000 RPM at 60-65 mph
3500 RPM at 50-55 mph
and so on

Any tips or explanations?? Or is it just my transmission going bad?

Anything will be helpful.
Thanks.

flyboyslc1

Since you said "anything" i will jump in! I have a 1991 stick transmission so not a direct comparison to your automatic. I know that my tachometer reads 5-600 rpm higher than engine speed. These tachometers are electronic and as far as i know internal parts go out of tolerance and the only way to fix them is to remove the cluster and have it fixed. So your tach may just be off. I just drive mine the way it is. If your trained ear really recognizes that the engine is indeed revving more than it use to, then likely a transmission issue either with slip or delayed shifting for one reason or another. One thing you could do is to go to a transmission shop and ask them to test drive your car. They would probably do this for free and give you a good evaluation.

steve

JC316

I'm with flyboy. That doesn't sound like an engine that's turning at 3K RPM, that sounds normal, betting that the tach is off.

Paul Workman

Hard to tell for sure, but .

OP: Go to most any auto parts store and hook a scanner onto it and read rpm to see if there is a tach calibration issue. Calibration is a relatively easy DIY (2-hour) fix in most cases.