Idle LOW @ 500.... temp issue?
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,656
Likes: 7,296
From: CT
Idle LOW @ 500.... temp issue?
Here is a new one I have seen in the past 5 days or so.
When the car is in the garage and I take it out to go somewhere, for the first 5 to 10 minutes the idle is odd. It drives perfectly fine, but when I go to neutral coming to a light or stop, the idle drops to 500 rpm. Eventually, the problem goes away.
Oil level is good and recently changed.
Secondary issue, unrelated, is that the External Air Temp sensor for my HVAC seems to have gone. It reads 60* when I start, no matter what. After some time it will read 69* with no gradual change. For one day it did gradually climb to actual temps. However, the temps have been mid 80s and up into high 90s and it stops out at 69* now.
Maybe it's suggesting something?
Back to main issue. When the car has been outside overnight, such as at my girlfriend's place, I start it and it does NOT repeat the idle issue.
This is what is making me think perhaps there is an issue with temp, and I therefore suspect the IAT sensor.
Can anyone think of a reason why I would or should be looking at other things as the potential culprit?
When the car is in the garage and I take it out to go somewhere, for the first 5 to 10 minutes the idle is odd. It drives perfectly fine, but when I go to neutral coming to a light or stop, the idle drops to 500 rpm. Eventually, the problem goes away.
Oil level is good and recently changed.
Secondary issue, unrelated, is that the External Air Temp sensor for my HVAC seems to have gone. It reads 60* when I start, no matter what. After some time it will read 69* with no gradual change. For one day it did gradually climb to actual temps. However, the temps have been mid 80s and up into high 90s and it stops out at 69* now.
Maybe it's suggesting something?
Back to main issue. When the car has been outside overnight, such as at my girlfriend's place, I start it and it does NOT repeat the idle issue.
This is what is making me think perhaps there is an issue with temp, and I therefore suspect the IAT sensor.
Can anyone think of a reason why I would or should be looking at other things as the potential culprit?
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
You most likely need to change the ac tensioner pulley and belt. If the tensioner is failing you will soon throw a belt.
Check out where the tensioner markers are lining up.
The outside air temp located at the nose of the bumper on the passenger side usually fails due to corrosion in the cable at the connection of the sensor.
Check out where the tensioner markers are lining up.
The outside air temp located at the nose of the bumper on the passenger side usually fails due to corrosion in the cable at the connection of the sensor.
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,656
Likes: 7,296
From: CT
As different projects get me in different parts of the car, I have begun using electrical contact cleaner to go through and clean things up. I have yet to find any that are other than pristine like new, but I'm guessing the outside air temp will break that trend.
Pulley? Maybe. I'll check it overnight.
I've got new belts ready to go, but also went ahead and ordered a new MAP sensor, outside air temp and inside air temp (prong cracked) since they are all so inexpensive. The car is old enough - may as well play it safe.
Now to find the P/N for the A/C belt tensioner.
Pulley? Maybe. I'll check it overnight.
I've got new belts ready to go, but also went ahead and ordered a new MAP sensor, outside air temp and inside air temp (prong cracked) since they are all so inexpensive. The car is old enough - may as well play it safe.
Now to find the P/N for the A/C belt tensioner.
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
As different projects get me in different parts of the car, I have begun using electrical contact cleaner to go through and clean things up. I have yet to find any that are other than pristine like new, but I'm guessing the outside air temp will break that trend.
Pulley? Maybe. I'll check it overnight.
I've got new belts ready to go, but also went ahead and ordered a new MAP sensor, outside air temp and inside air temp (prong cracked) since they are all so inexpensive. The car is old enough - may as well play it safe.
Now to find the P/N for the A/C belt tensioner.
Pulley? Maybe. I'll check it overnight.
I've got new belts ready to go, but also went ahead and ordered a new MAP sensor, outside air temp and inside air temp (prong cracked) since they are all so inexpensive. The car is old enough - may as well play it safe.
Now to find the P/N for the A/C belt tensioner.
12568181 – 01-04 – Serpentine Belt
Or get a katech for bling and manually set it.
I decided to use the 01-04 model on my 00.
It has a higher lip on it and will avoid belts slipping off. The only trick is that during belt install using an 01-04 on an earlier model requires you to slip the belt over the water pump last instead of the tensioner last.
Last edited by Got uid0; Jul 2, 2013 at 07:16 PM.
Thread Starter
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,656
Likes: 7,296
From: CT
Good info. Thanks again.
01-04 is $76 @ GMPartsWarehouse (my GM dealer of choice!)
Katech's tensioner is $119 currently.
I'm going to wait 24 hours and see if a sale pops up. I saw where they were letting them out the door for $89 a few months ago. The car is parked for now - stage 5 fever, plus my dog got sprayed by a skunk tonight. The fun keeps on rolling!
01-04 is $76 @ GMPartsWarehouse (my GM dealer of choice!)
Katech's tensioner is $119 currently.
I'm going to wait 24 hours and see if a sale pops up. I saw where they were letting them out the door for $89 a few months ago. The car is parked for now - stage 5 fever, plus my dog got sprayed by a skunk tonight. The fun keeps on rolling!
