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View Full Version : Is this normal? (Coolant Temp Gauge)


07X3platinum
02-13-2007, 10:18 AM
2007 X3

The weather in Chicago has been brutally cold the past few weeks. When I start the car I make sure the Climate Control is completely off until the car warms up.

Once the needle for the Coolant Temp Gauge reaches the middle I turn on the Auto Climate Control (with the A/C turned OFF), but the needle instantly goes back down about a quarter of the way. Is it normal for the needle to go down like that or could there be a problem with the sensor?

As I keep driving the needle slowly goes to the middle (normal) position. I'm just confused as to why the needle would suddenly go down by turning on the Climate Control.

Should I just leave the Auto Climate Control on all the time even when I turn the car off?

brh_minn
02-13-2007, 11:53 AM
I live in Minnesota, and obviously we have been having the same conditions here. Brutal cold. I always leave my climate control on in the car, and it just starts to blow when the car heats up. I have not paid attention to the temp guage, except that it is pinned left for quite some time.

If I remember, tomorrow morning, I will shut off the climate control and repeat your experiment to see what happens. It is supposed to be -4 overnight, so It should be a good test.

AzNMpower32
02-13-2007, 01:12 PM
I dunno, I just leave mine on all the time. It only seems to start blowing heat when it has enough heat to spare. which is usually after a minute or so. I do realize it takes awhile for the engine to warm up in really cold weather though.

dug01
02-13-2007, 02:05 PM
2007 X3

The weather in Chicago has been brutally cold the past few weeks. When I start the car I make sure the Climate Control is completely off until the car warms up.

Once the needle for the Coolant Temp Gauge reaches the middle I turn on the Auto Climate Control (with the A/C turned OFF), but the needle instantly goes back down about a quarter of the way. Is it normal for the needle to go down like that or could there be a problem with the sensor?

As I keep driving the needle slowly goes to the middle (normal) position. I'm just confused as to why the needle would suddenly go down by turning on the Climate Control.

Should I just leave the Auto Climate Control on all the time even when I turn the car off?

Could it be that turning on the climate control opens up the valve to let hot coolant into the ice cold heater core and plumbing?? And then you blow cold outside air over it--It will take the engine thermostat a few minutes to close down to warm up the coolant again--its normal. :thumbup:

jcarlilesiu
02-13-2007, 02:13 PM
I live in chicago too. Hi neighbor, Uptown here. Anyway.... I don't have the automatic climate control in mine, just the manual controls. I have found out that the car heats up faster if I leave the heater completely off while the car warms up. Once it gets up to the normal range, then I turn the heater on. Im guessing that since the engine is cold, and you are attempting to pull heat from it for the cabin, it takes longer to fully warm up. Thus by leaveing the blower/heater off, it allows the engine to heat up faster.

What is probablyhappening with yours is that the engine is warming up, but as soon as you turn the climate control, its cooling it right back off again, with out the engine being able to maintain that heat.

Cars do funny things when its -30F with the windchill. On a side note... have you noticed a ticking noise coming from the engine until it fully warms up? I always panic in the winter because of all the funny noises and such.

Ishniknork
02-13-2007, 06:34 PM
Could it be that turning on the climate control opens up the valve to let hot coolant into the ice cold heater core and plumbing?? And then you blow cold outside air over it--It will take the engine thermostat a few minutes to close down to warm up the coolant again--its normal. :thumbup:
Exactly. My temp gauge does the same thing if I wait for the engine to warm way up before turning on the heater. Freaked me out the first time I noticed it but then I figured out what was happening. Now I just turn the fan way down so all the parts can warm up at the same time.

brh_minn
02-14-2007, 06:14 AM
to 07X3platinum :

Tried it this morning. Exactly as you described. Although the needle plunged, it came back very quickly, I could see it move slowly back to near center position.

07X3platinum
02-14-2007, 07:20 PM
Thanks for the replies everyone.

To "jcarlilesiu": From my experience, BMW engines make strange sounds when they're cold and even when they're warmed up and in idle. I haven't heard any "ticking" coming from the engine when I'm inside the car, but I'm sure it would make some strange noises if I rolled down the window or stood outside of the car.