rpm gauge flutters when warm

**jjrobjohn** · 05-08-2009, 05:33 AM

got a 1999 2wd chev silverado with a 4.3l Whe the truck warms up I get a flutter on the rpm gauge when the truck is under load or I give it gas. Tried everything to fix it and can't find the answer. I replaced plugs,wires,rotor,dist. cap, fuel filter, fuel pressure good, cleaned EGR valve. It runs like a top when it is cold ,but as soon as it hits a certain temp it flutters on the rpm gauge and goes from 2000 to 4-6000 constantly. Almost seems like a serge or miss.
Any body out there with ideas.

Thanks

**cascott325** · 05-08-2009, 03:10 PM

have you thought of your cats? or o2 sensors?

**RADO_4U2NV** · 05-10-2009, 10:39 AM

Originally Posted by jjrobjohn

got a 1999 2wd chev silverado with a 4.3l Whe the truck warms up I get a flutter on the rpm gauge when the truck is under load or I give it gas. Tried everything to fix it and can't find the answer. I replaced plugs,wires,rotor,dist. cap, fuel filter, fuel pressure good, cleaned EGR valve. It runs like a top when it is cold ,but as soon as it hits a certain temp it flutters on the rpm gauge and goes from 2000 to 4-6000 constantly. Almost seems like a serge or miss.
Any body out there with ideas.

Thanks

When the rpm's flutter is your motor reving with the tach or is it just the tach jumping around. I know the the cluster starting in '99 have trouble with the motors in the gauge cluster. My speedometer was the motor thatwent out in mine.