Author Topic: Temp Gauge reading Colder than normal? (Read 2569 times)

H8Rain · « **on:** May 23, 2011, 05:23:49 PM »

So here's the deal. Took a 200 mile trip. During the entire trip, as I cruised at around 70mph the temp gauge read slightly colder than normal (needle was at about 10 o-clock). When I would get stuck in some traffic and idle or drive about 10mph the temp gauge would go up to normal (needle at 12-noon).

I'm used to overheating issues, but this ones got me confussed?

Any suggestions?

MikeDE · « **Reply #1 on:** May 23, 2011, 05:33:21 PM »

Most likely t-stat is getting sticky, I have had some also that have stuck open. My E36 M3 would barely get above 1/4 when this happened. I just swapped one on an E46 323i that was stuck open. And my 318i(M40) was like that when I bought it.

monty23psk · « **Reply #2 on:** May 23, 2011, 10:57:09 PM »

Seems normal with a lot of air hitting your engine constantly. Mine does this and has new tstat and temp coolant sender.

DesktopDave · « **Reply #3 on:** May 24, 2011, 07:11:05 AM »

How long does it take to heat up? That'd be the easy way to check the thermostat. You could also do a temperature resistance test on the sensor...those don't last forever.

bmwman91 · « **Reply #4 on:** May 24, 2011, 12:55:15 PM »

It is most likely the thermostat. They usually fail open & run the motor cold (which is better than the alternative).

If you do replace it, make sure to use the 88C one, not the 80C one.