High Idle

If the idle is that high I would suspect the PCV valve has failed. Replace the PCV valve and see if the idle is better.

sorry, I did not see that you have the 5.3. if the idle is that high you must have a check engine light and a code. if you can tell me the code I can help. if there is no code I would suspect the following;
bad mass air flow
bad map sensor
vacuum leak

My son had it on a scanner and there are no codes and no leaks of any kind. The engine i should have told you is a 5.3 v8 displacement.

There was one code. It was i believe P507? Mentioned the throttle body or possible PCV. This car does not have a PCV and we just put a new throttle body on it yesterday.

Okay, if you can get the codes scanned again and let me know the code number I can advise.

Most times if there is a throttle body or pedal sensor issue there will be a "reduced power" message on the dash. the common items are the pedal assembly or the throttle body or the connections to each.

I just talked to my son and he said the code was P507.

Yes, it did say reduced power but when the throttle body was replaced and the new pedal that message went away.

That is not enough digits. There will always be a P followed by four numbers.

If the reduced power message went away then that is a step in the right direction. You can try and relearning it by turning the key on and not starting the engine. Press the gas pedal all the way to the floor and let up. Shut the key off and then start it. See if it helps.

P0507.

Okay, thank you. I will try that now.

Okay, i did what you said. When i start it it goes up to about 2000 rpm's and drops down to about 900.

Okay, does it accelerate fine now ?

Yes but, shouldn't the idle for this car be between 600 and 700?

The code P0507 just means that the throttle body cannot restrict the rpm to at least 200 rpm's from the desired rpm. So if it cannot the possible causes are vacuum leaks or deposits on the throttle body or a failed throttle body. Since you replaced it if the issue keeps happening then the engine needs to be checked for a vacuum leak.

Okay, thank you.

The idle will be whatever the engine computer wants it to be there is always a possibility of a failing motor in the cluster so the rpm is not reading correctly.

Could cold weather make it idle a bit higher then usual?

What do you mean by a failing motor in the cluster?

It can. As long as there are no codes and the car drives fine and accells fine then there is no reason for alarm. Ideally rpm is usually 700-800 roughly but with the newer automatic throttle bodies the engine module has total control.

The needles in the dash display are little motors that go bad and do not give a smooth transition and get stuck at certain points.

Oh okay. Well thank you for all your help. It is late so i will let you go. I appreciate you help.

Lastly we have what is called a idle relearn. With the gm tech 2 scan tool. So worst case you may need to have a dealer perform this if the idle stays too high. That is what I had you try and do with the gas pedal trick but it is not always successful. Hope I was somewhat helpful.

The Idle is still about 850-900. Is that something that we should really worry about?

Is the check engine light gone ? It's hard to say if you should worry about it if there is no check engine light. At this point you would need a scan tool that can show the specified rpm vs the actual rpm to know if the module is commanding the system to hold the rpm there. We have a Monte Carlo in our shop. I'll compare.

Ours is right between 900-1000

After a few minutes of warm up we are at about 750-800

Honestly without a check engine light I would not worry about it. This one we have hear if you listen to the dash closely the motor for the needle is really loud and probably sticking. So actual rpm may vary. Hope this information helps.