When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My car keeps idling at 500 in drive on a hot day but when I turn the A/C on it idles at 750 like normal, cleaned my MAF and throttle body 2 times already and my air filter. Still have the same issue and was wondering is that normal because in FL it gets really hot outside and at night my car idles at 750 or 650.
The idle speed is determined by the ECU in response to whole raft of sensor measurements.
When you switch on the AC you add a 2Bhp load to the engine, so it increases the idle to compensate.
Personally I wouldn't worry about it. If it starts stumbling or misfiring, then you have an issue.