High idle when my 2000 silverado is warm

Honestly, I have a 1993 2.8 L V6 and it's always idled high when warming up. They're rather notorious for that for some reason lol

you have a bad idle air control valve. its job is to have motor rpm high until the motor warms up then turn it back to normal.

The most common cause of high idle is an intake air leak. It will cause a lean condition to the O2 sensors and the PCM's solution is to increase the fuel mix resulting in faster idle. It can also cause a Check Engine Light if the idle remains too high for too long. Do a smoke test or soapy water test around the intake manifold and throttle body. If you detect any leaks, seal them and try again.

Typically high idle occurs when vehicle is started when cold. The idle will go down when the vehicle warms up.

clean idle air control assyembly.it's a round cylinder on intake.just unbolt it and clead with carb cleaner.shoot lots into seat on intake

try redexe petrol additive.could be carbon buildup.when you take to the highway do not use heavy acceleration,but build up speed gradually..could also be sticky throttle cable.....

It sounds like your thermostat may be stuck open, with the engine working hard the temperature of the engine comes up thus the warm air, but just at an idle the thermostat is letting the coolant circulate and not holding it their until it reaches a warm enough temp. You are most likely going to need to change the thermostat.

try a new idle air control valve

CAR & TRO CLEANER

Sounds like it's time for a tune up of the ignition system. That would be easiest. If not, have a mechanic check your cylinder compression.