Running Warm at Idle

[orange57]

Hey guys,

I have a 00 Limited, it's a great truck. However, today, while sitting at idle in a parking lot, AC on, the truck temp started to rise to the 210 mark in the dash. Once moving again the temp dropped pretty quick. This is pretty recent, never had an issue before.

First thought was fan clutch. Did a quick check, it does not spin freely. Spins about a quarter turn before stopping. Could that be an idicator of the clutch being bad?

Thermostat is about 9 months old, as is the coolant. I did the Intake Gaskets about 9 months ago and that is when the Tstat was also done. Not to say it isn't the culprit.

Just wanted to get the groups take before I start replacing parts.

Thanks,

matt

 

[SunlitComet]

what rating of t-stat did you use?

 

[orange57]

what rating of t-stat did you use?

It was the oem rating. I believe 195.

 

[God]

How long had you been driving? My Tstat usually takes a few minutes to open, and opens at around 210 and after it opens stays around 170ish I believe

 

[SunlitComet]

getting up to 210 is not abnormal but the way you describe it it sounds like it is delayed a bit and suddenly pops open and and closes at a rate just as fast as it opened. it sounds like a t-stat that is not throttling properly. if you are sure the fan clutch is operating properly the redo the t-stat. a good test for the clutch is to let the engine get cold. start it and listen for the fan to howl as you jack up the rpm's say 2-3k after a short amount of time the clutch will loosen it's grip and not howl so much till it sees a lot of heat from the rad again. if you think you hear howling at higher rpm when the temp gets up your clutch should be fine.

---------- Post added at 06:44 AM ---------- Previous post was at 06:43 AM ----------

How long had you been driving? My Tstat usually takes a few minutes to open, and opens at around 210 and after it opens stays around 170ish I believe

that is to low to stay open at. I suggest yo may need a new one as well.

---------- Post added at 06:48 AM ---------- Previous post was at 06:44 AM ----------

I would suggest you guys use a delco or stant t-stat. I have not had any defective stant products before and they do great thermostats and gas caps as well.

 

[orange57]

How long had you been driving? My Tstat usually takes a few minutes to open, and opens at around 210 and after it opens stays around 170ish I believe

I had driven around 15 miles, then st idling for about 15 minutes. The temp dropped back down once I started moving again.

 

[SunlitComet]

are you sure the system is completely bled out of air?

 

[orange57]

are you sure the system is completely bled out of air?

Pretty sure. It has been 5-8k miles since I did the intake gaskets. Had to add a little bit of coolant right after, but nothing since. And going down the road the temp is fine. Even in the 110+ days here. It was only during idle. And after sitting for around 15 minutes with the AC on.

I will have to listen tomorrow morning to see if I really hear the fan howl. If not, may need to start with the fan clutch. When it cools down I will pop the radiator cap to try and see how the coolant in the radiator looks too. The overflow tank seems fine.

 

[God]

What's the correct normal operating temp?

I think it's kinda dumb that our gauges have 210 in the middle
Whereas many other cars have their normal operating temp in the middle...

 

[SunlitComet]

not at all. in fact running at 210 is not all that bad. when you drive in the city under hot weather with the a/c on it is totally expected. expect more with towing.

the temp will go up and down but mine rests at about 193 at idle to 213 before my fans turn on i think. i could make it tighter but no need.

---------- Post added at 04:33 AM ---------- Previous post was at 04:31 AM ----------

Pretty sure. It has been 5-8k miles since I did the intake gaskets. Had to add a little bit of coolant right after, but nothing since. And going down the road the temp is fine. Even in the 110+ days here. It was only during idle. And after sitting for around 15 minutes with the AC on.

I will have to listen tomorrow morning to see if I really hear the fan howl. If not, may need to start with the fan clutch. When it cools down I will pop the radiator cap to try and see how the coolant in the radiator looks too. The overflow tank seems fine.

Giving that info i don't think you have much to worry about. it does seem like the stat maybe a bit sticky however giving your environment i see no harm being done to the engine. if you get into the 220's while driving with out a load then you may need to be concerned.

 

[orange57]

Well the gauge isn't very accurate as I have checked it before using torque pro.

Anyways, I think it is the fan clutch. Took off in the truck this morning and the fan want howling like it normally is first thing in the morning. I will pick up a new one and see how that does.

Thanks,

Matt

 

[SunlitComet]

if it did howl and then calmed down in a minute or so then it seems fine so far. it show the fluid settled overnight and gripped it self hard but once working hard it loosened itself up as expected. at that point what you want is to see the engine get really hot and the fan will grip tight again and start howling indicating the clutch is reacting to the heat.

 

[orange57]

if it did howl and then calmed down in a minute or so then it seems fine so far. it show the fluid settled overnight and gripped it self hard but once working hard it loosened itself up as expected. at that point what you want is to see the engine get really hot and the fan will grip tight again and start howling indicating the clutch is reacting to the heat.

No, there was no howl at all from the moment I started moving. I do recal that I would hear the howl heading out of my neighbor hood and feel the drag on the engine. Nothing today. Even when I left for lunch. I will swap out the clutch and go from there.

 

[SunlitComet]

lets put it this way. if you are getting the same effect on your temp gauge on a 110+day with a/c on and you stay around 210-220 or lower the fan clutch may just be fine. you have to get the engine really hot to get the clutch to get full grip on the fan. but by all means look at the front of the clutch and make sure the thermo spring end tab has not popped out of the tabs on the body that hold it in place.