Turbo advise

[Luce]

It wouldn't surprise me if this was normal. Modern cars are not intended to sit and try to hold a 1500 rpm idle unless the ECU is doing it for a reason.

I've tried doing the same on a few different cars in the heat of the day to get a little extra A/C while sitting in park in the sun waiting on something.

[Gaz64]

Originally Posted by Luce

It wouldn't surprise me if this was normal. Modern cars are not intended to sit and try to hold a 1500 rpm idle unless the ECU is doing it for a reason.

I've tried doing the same on a few different cars in the heat of the day to get a little extra A/C while sitting in park in the sun waiting on something.

That's exactly correct.

The ECM only NEEDS to open the throttle if the transmission is in gear, and foot off the brake. The throttle blade is ECM commanded when conditions are met, so IF the driver applies the throttle pedal and the brake pedal at the same time, the brake pedal has precedence.

Free revving the engine can be difficult in some cars, especially to hold a fixed speed. Most are rev limited to about 4000 while in Park or neutral.