• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

High idle?

WhiteGT

WhiteGT

New member
Hi guys

I find my car (3800 na) will idle high most of the time. When you first start it cold it stays up around 1500rpm for a few mins, then goes down under 1000. Once warmed up and in drive it's usually in the 800rpm range but when put in park it will usually jump to just under 1000rpm. I am going by the idle in other v6's I have had (3.1L) and this one seems kind of high. My throttle body and idle air control valve has been cleaned really well recentlly so that shouldn't be the problem. Any info is appreciated.
Thanks.
 
Last edited:


The Idle Air Control motor still could be bad or not responding properly to PCM input. One way to tell for sure would be if you had a scan tool and look at the IAC. Another way would be, if you have another GM V6 around, to swap it out with the IAC from one of them and see if that makes any difference.

I guess it could be your MAF sensor too if its dirty, so you might get some electronics parts cleaner and clean that up and see if that helps.

One other possibility and Ive seen them do this before, but not as frequently on a GP. Your Throttle position sensor could have a dead spot in it or weak one right around the idle position. However, it is typical for a TPS to cause shifting issues too. But if the idle issue were the result of a developing dead spot rather than a completely failing TPS I dont know if we would see the shifting issues.

Hope this helps out. Oh, be sure your air filter is clean too. If the engine is struggling to get air its going to raise the idle some in order to get what it needs.
 
Thank's for the info. I have a spare idle air control motor in my toolbox so I will try swapping that out. I have electronics cleaner as well. I was going to clean the maf before but thought the cleaner might damage it. The air filter is not new but not terrible, I will probably get a K&N soon, that's why I have not replaced that yet. Maybe there is a bad spot in the tps though too because sometimes it seems like it misses a bit durring highway driving so I will try to get a hold of one of those to try as well.
 
WhiteGT said:
Hi guys

I find my car (3800 na) will idle high most of the time. When you first start it cold it stays up around 1500rpm for a few mins, then goes down under 1000. Once warmed up and in drive it's usually in the 8000rpm range but when put in park it will usually jump to just under 1000rpm. I am going by the idle in other v6's I have had (3.1L) and this one seems kind of high. My throttle body and idle air control valve has been cleaned really well recentlly so that shouldn't be the problem. Any info is appreciated.
Thanks.
Click to expand...

What?!?!?!?!:th_wtf:
 
I cleaned the maf sensor and the air temp sensor while I was at it with the electronics cleaner. I also took the idle air control out and worked it in and out all the way with intake cleaner and it seemed to move alot smoother so hopefully this helps. I think I will pick up a K&N drop in too since the air filter has seen better days.
 


So after trying those things, it still idles the same. Maybe that's normal for these cars. What do other peoples cars idle at?
 
After warming up and reaching operating temp, with it in park or neutral, ac compressor off, mine idles about 650RPM. Add 100 RPM if the ac compressor is on.
 
Sabrewings said:
After warming up and reaching operating temp, with it in park or neutral, ac compressor off, mine idles about 650RPM. Add 100 RPM if the ac compressor is on.
Click to expand...

See mine is around 800rpm and up in those same conditions. That's why I am thinking something is a bit off. When I put it into park after driving it usually jumps up to around 1000rpm's and drops in between 800-1000rpm's. When I let it idle, it does stumble slightlly as well. I have scanned the car a few times at the garage I used to work at but it never shows anything.
 
All 3800s have the slight stumble at idle.

What are you using to get your RPMs? Your dash? The needle may not be perfectly calibrated.
 


Sabrewings said:
All 3800s have the slight stumble at idle.

What are you using to get your RPMs? Your dash? The needle may not be perfectly calibrated.
Click to expand...

Mainly the dash, but I have also checked it with a snap on scanner and I know it was higher than it said it should have been. I will hook it up again this week if I get a chance for a more accurate reading.
 
WhiteGT said:
Hi guys

I find my car (3800 na) will idle high most of the time. When you first start it cold it stays up around 1500rpm for a few mins, then goes down under 1000. Once warmed up and in drive it's usually in the 800rpm range but when put in park it will usually jump to just under 1000rpm. I am going by the idle in other v6's I have had (3.1L) and this one seems kind of high. My throttle body and idle air control valve has been cleaned really well recentlly so that shouldn't be the problem. Any info is appreciated.
Thanks.
Click to expand...

Did you fix the problem if so what was it?
 
usually a high idle is attributed to a vacuum leak somewhere....not always, but probably 80% of the time or more.
 
bluegtp91 said:
Way to go...thread is going on a year old...
Click to expand...

I think its better to search old treads and try and find your answer instead of creating new ones so people can answer the same questions over and over.

I just wish people would come and add a post when they fix the problem it can really someone else out. I think that is what forums are for to help each other out.
 


You must log in or register to reply here.
Back
Top