Concerned about fluctuating engine temperature. Please help.
Thread Starter
Racer
Joined: Jul 2007
Posts: 397
Likes: 1
From: Tucson Arizona
Concerned about fluctuating engine temperature. Please help.
Can someone please help? I'm concerned about my engine temperature. It fluctuate a bit too much and I'm not sure it's normal.
My car under normal freeway driving conditions in 100 degree weather runs at about 220, sometimes less maybe 215. In traffic it runs at 220 but at a stop light it sometimes raises up to 230. It then goes back to 220 when I start driving again.
Today I made a stop at the bank and had the car off for 2 minutes. When I started it back up the temperature went to 235-240! I can live with it going up to 230 at a long light in the heat but it does this all the time... and 240 seems way high! It also smells hot when I get home in the afternoon, not to bad but I do notice it.
The coolant level is good, 50% Dex-Cool 50% water mix. The fans kick on, but the temperature just fluctuates all the time on the HUD and gauge. Does anyone have a checklist of things I can look at to find the problem, or am I being paranoid?
I'm going on a long trip next month and if there is a problem I would like to find it now. Any help will be greatly appreciated.
Some background on the car, it's a 2000 M6 with 65k miles. The color is black could that be the cause of the rising engine temps!?
My car under normal freeway driving conditions in 100 degree weather runs at about 220, sometimes less maybe 215. In traffic it runs at 220 but at a stop light it sometimes raises up to 230. It then goes back to 220 when I start driving again.
Today I made a stop at the bank and had the car off for 2 minutes. When I started it back up the temperature went to 235-240! I can live with it going up to 230 at a long light in the heat but it does this all the time... and 240 seems way high! It also smells hot when I get home in the afternoon, not to bad but I do notice it.
The coolant level is good, 50% Dex-Cool 50% water mix. The fans kick on, but the temperature just fluctuates all the time on the HUD and gauge. Does anyone have a checklist of things I can look at to find the problem, or am I being paranoid?
I'm going on a long trip next month and if there is a problem I would like to find it now. Any help will be greatly appreciated.
Some background on the car, it's a 2000 M6 with 65k miles. The color is black could that be the cause of the rising engine temps!?
Drifting
Joined: Apr 2010
Posts: 1,443
Likes: 7
From: Bristol raceway area
Your temps. are to high. Check for trash and debris in front of the a.c. condenser and front of the radiator. These cars are "bottom breathers" and pick up a lot of junk. Our '02 had a lot of debris there. Have you opened the cooling system for any reason? If so there could be an air pocket in there. You might need a new stat too. With a coolant change and a 160* stat, our car runs 172- 176 driving which is just where i like it. Good Luck
Intermediate
Joined: Sep 2009
Posts: 32
Likes: 0
From: Kansas City MO
Mine ran 220 while driving and 230 at stoplights. I think the high fans don't even come on til 230 but im not positive on that. Some say this is normal but i didn't like it. Thought the radiator was dirty, cleaned that and it didn't help. Changed thermostat and problems are gone. I went with a 160. When it is cool out it runs around 170. Its been getting up to around 90 degrees here now and it runs about 180 or so cruising on the highway. To take full effect of the lower thermostat you need to get reprogrammed to have the fans kick on sooner because if you sit at a stoplight to long it will still get hot. What i do is turn the ac on if i sit to long, it turns the fans on low this is temperary until i get a reprogram.
Burning Brakes
Joined: Oct 2004
Posts: 931
Likes: 35
From: Rowlett, Texas
When the AC is off, the low-speed fans don't come on until 226. So, if you are sitting still, the motor will quickly reach that temp. Then it should cool down to 216 and the fans stop again. So, it should cycle 216-226 (approx) when not moving. Above 35 MPH, the fans stop and the ram effect cools the radiator. Even with a stock thermo, at hiway speeds it should always run under 200.
With AC on, the fans will run all the time below 35 MPH, so the engine will actually stay cooler at a red light with the AC on.
The high speed is set about 10 degrees higher, and comes on about 240 if the low-speed can't handle it.
If you park the car and let it sit a few minutes, it will heat soak quite a bit, and probably see 240 when first recranked. Should come right down though.
A good functioning system should never really require hi speed fan with the AC off, except maybe for a few seconds after a stopped-engine heat soak.
That being said, how is your front air dam? It can highly affect airflow when moving.
as stated above, crawl under and check the debris in the condenser & radiator.
Unbolt the big plastic cover on top of the radiator and check down between the radiator and condenser; you will find a lot of debris in there if it's never been cleaned out.
DG
With AC on, the fans will run all the time below 35 MPH, so the engine will actually stay cooler at a red light with the AC on.
The high speed is set about 10 degrees higher, and comes on about 240 if the low-speed can't handle it.
If you park the car and let it sit a few minutes, it will heat soak quite a bit, and probably see 240 when first recranked. Should come right down though.
A good functioning system should never really require hi speed fan with the AC off, except maybe for a few seconds after a stopped-engine heat soak.
That being said, how is your front air dam? It can highly affect airflow when moving.
as stated above, crawl under and check the debris in the condenser & radiator.
Unbolt the big plastic cover on top of the radiator and check down between the radiator and condenser; you will find a lot of debris in there if it's never been cleaned out.
DG
Thread Starter
Racer
Joined: Jul 2007
Posts: 397
Likes: 1
From: Tucson Arizona
I will check the radiator for bags etc… when I get home. Car ran 210 all the way to work this morning all freeway. I will also go down the list check the fluid for color etc. I am getting new tires soon so I may just have the radiator flushed at that time. To my knowledge it has never been changed, it has 64k miles but it has been longer than 5 years.
If nothing else fixes the fluctuating temperatures I may just get a new stat and have it reprogrammed.
Yes a black car in Tucson, thank goodness for the car duster! Thanks for all the help!
If nothing else fixes the fluctuating temperatures I may just get a new stat and have it reprogrammed.
Yes a black car in Tucson, thank goodness for the car duster! Thanks for all the help!
