Idle problem when hot

Hello,

This sounds like you probably have two issues going on here. The first is probably going to be your vehicle's Idle Air Control valve (IAC). This valve is controlled by your vehicle's Power-train Control Module (PCM) or "computer", and is responsible for letting the correct amount of air enter your engine around the closed throttle plate at idle. The second issue is the "searching" at idle, going from 500 to 1000 rpm's, which could, again, be your IAC, but is probably an intake leak. By an intake leak we mean, any unmetered air(air the PCM doesn't know about) entering your engine's combustion chamber from the Mass Air Flow sensor(MAF) to the combustion chamber. It could be the air intake duct, vacuum lines, EVAP lines, but is usually the intake manifold gasket. Here is a link for you to go on intake leaks:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let's start with the IAC first. Clearing up this problem might fix everything. In the diagrams down below I have included a diagram with the location of the IAC and a diagnostic troubleshooting guide for your vehicle's IAC. Please go through these guides and get back to us with what you are able to find out. You will have to use a multi-meter to do these tests, so, here is a link if you are unfamiliar with how to use one:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Thanks,
Alex
2CarPros