is my car actually "running warm" or is this how things are supposed....

[ryan roopnarine]

to be?

some background...i know that my coolant temp sensor is dying, as before it hits 12 o'clock it likes to undulate on the way up. the real telltale of this is that if i drive the car in the heat for a few hours, then park for half an hour, the tranny goes into sport (ie the car thinks its just been in a cold start) for a few shifts before it works normally again.

previously, in the nasty florida heat (85 deg F at 12 AM), the car would get up to 12, and stay at 12, no matter what (unless i was driving on the highway for 30 mins or more, in which case it would run about 1/2 needle below the centre. i began increasing the antifreeze concentration from an unknown quantity (around 30 percent antifreeze 70 water) to maybe 40 right now, and increasing......after the last dose of straight antifreeze, i noticed that when driving, the car will do about 1/2 needle below 12 o'clock when driving. when parked up in the heat now (for more than 15 minutes), however, the temp willgo to about 1/2 needle above 12

on brunos' pic, here, it would be about 187 deg or so


and be about 177 when driving. before it was consistently at 182 unless parked for a real long time, where it would get to about 187 or so.

i know, also that i need to do capacitors on the cluster, which might account for some of the weirdness with the gauge.

having said all this, summing up

car runs cooler than before when driving after adding more and more antifreeze, warms up a bit when parked (to about 187)

before adding antifreeze, car would run 182 all of the time, unless parked more than 20 mins, would rise to 187.

any thoughts?

PS...forgot to add. car IS NOT overheating. the car's temperature hits a brick wall at 187, it won't go any further, and goes down quickly if you drive it when it does this. to the best of my knowledge this started happening after i increased the antifreeze concentration.

[DanH]

187 is probably as cool as your fan clutch can keep it with a wide open thermostat and without additional airflow from driving. And your thermostat keeps it from going below 182 (or whatever it rating is) while you're driving.

There doesnt seem to be anything especially abnormal.

[DanH]

Also, The maximum temperature while parked is going to increase over the life of the fan clutch, until it is worn out, then your car will overheat while the car sits and still run normal temps at higher speeds and during cooler weather.

[uscharalph]

Seems fine. The only thing that would bother me is that you don't know what percenteage of coolant / water is in there. I'd flush and start new, with a know percentage of concentration.

[Robin-535im]

Sometimes a nice fresh flush/refill will make a car that is kinda overheating come back to normal. It's cheap! You can use distilled water at 100% if you want until it gets cold. $0.50 a gallon at walmart.

[Derek A.]

Wiggle the connector for the coolant temp sensor, or unplug and plug it back in several times. See if your gauge acts differently .

[Dave M]

This is exactly how my 525im acts. As low as one needle width below in cooler temps on highway and up to on needle width above in hot weather at idle. Never second guessed it as the lower rad hose is almost always cool to warm.

Best of Luck,

Dave M

[632 Regal]

I would have to add that the amount of antifreeze is helping the engine transfer the heat from the engine to the fluid. If you have no antifreeze it will not transfer thus the inventation of water wetter. If your too thick the antifreeze dont transfer heat well either and thats what I think you have discovered . the thermo factor, which is different between different antifreeze manufacturers also. I hope this test has been done and documented with Cool Blue for everyones best interest .

[ryan roopnarine]

haw haw

PROBLEM SOLVED!

i suspected that the radiator cap was bad because of a slight "toothpaste" stain around the filler hole. i carry a cap as a spare part so i decided to put it on....back to the way it was!

25 mins idle at 95f outside temperature keeps things straight 12 o'clock as opposed to 187 degrees with the bad cap, car cools slightly (not as much as before at all) when you pull away.

its weird that a defective rad cap would make the car run cooler.
im not pleased, however. this cap isn't more than 70k miles old. this doesn't say good things about my cooling system if this item fails so soon.

[632 Regal]

if I read the Encyclopedai Brittanica and the answer is glad bags im somewhat dissapointed.