Heater on, temp rise ?

Post your E12 technical questions and comments here. Please, no off-topic posts.

Moderators: Mike W., Pierre

Post Reply
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Heater on, temp rise ?

Post by T.Hanson »

Built, installed 56,000 mi. engine w/new peripherals 2 years ago. Flushed radiator, new water pump, hoses, thermostat. Runs good, no problems, save sensitive throttle I drive around. 100 degrees humid, an hour in parked traffic last summer the temp needle rose only slightly. No a/c on.

Not driven in winter for years. Turning on the heater and blower noted a slight rise in temperature on the gauge. Not large, but higher, similar to hot summer.

I thought turning on the heater was a trick for lowering temps. No problems, it never went nuts, much above the 12 o'clock mark, just curious.

Might the heater core be full of old crunchies ? No noises, nothing visible while hoses were off. Just watch and drive or action required ?
User avatar
Lenny D.
Posts: 287
Joined: Wed Jan 07, 2009 3:05 am
Location: New Orleans (Metry!), LA
Contact:

Post by Lenny D. »

More likely an electrical issue affecting the temp. gauge. I notice when I crank up the fan speed, the temp. gauge will (ahem) become slightly more erect. :shock:

Unless you want to chase unnecessary solutions, I'd just make a mental note, and drive away. Having said that, the electrical issue is/could be under dash grounds (and the subsequent path back to the battery) and/or more likely, the flaky ribbon wiring harness that's riveted in places to the cluster, one of which is an all important ground point, one for the temp. gauge and one for the gas gauge.

See my post.
HTH

'80 528i
T.Hanson
Posts: 1696
Joined: Wed Jul 26, 2006 7:39 am

Post by T.Hanson »

Thank you, as usual. Darned if the fuel gauge hasn't been hinky, sticky once in awhile to note your post, set the mileage meter to extend procrastination time.

If I don't croak, next spring the cluster is coming out for rejuvenation.
User avatar
Mike W.
Posts: 2889
Joined: Wed Aug 30, 2006 12:12 am
Location: Sonoma County

Post by Mike W. »

Definitely a ground issue. Run an extra wire between the engine and the body and see what happens. If that fixes it, and I suspect it will, go from there. :D
Mike W.



02 525ita. Wife's, aka grocery getter
02 530i. New to the fleet, 3 pedals.
03 QX4, AKA the Datsun. Finally got the 4WD vacationmoble to stop smoking.
07 Xterra. Still on the DL, a purchase from hell.
Post Reply