Overheated Once

[monoblanco]

Has not overheated since, but my temperature gauge goes back and forth ranging between midpoint and a quarter higher. Bad thermostat? Should I sell it? Sent from my HD1907 using Tapatalk

[tomstin]

When was the coolant last flushed? When was the water pump replaced? How about the thermostat?

Where you driving down the highway or stuck in traffic? Could be the fan clutch if you were idling in traffic.

Could be a lot of simple things...

[e30vert]

Also could be a bad ground

[ADEN]

Thermostat opens a little late due to air in the system.
Bleed it the right way and you are good.

[nando]

1/4 past the middle isn't much to worry about, I mean I wouldn't want it to run that hot all the time but it's not really what I'd consider overheated. 3/4 on the gage is about 90c. Newer BMWs run hotter than that stock.

There have been so many dumb "I don't trust the gage because I don't understand it" posts through the years. E30 coolant gages work fine. They are reliable (if it hasn't been messed with). Engine temperatures DO fluctuate. That is why BMW nerfed the coolant gages after the E30 - and eventually removed them entirely.

The real question is *why* is it fluctuating so much. Air pockets in the coolant system? A loose ground nut on the cluster, or a bad connection and the sensor? Is it bouncing around or does it sometimes get to 3/4 when you're sitting in traffic for an hour? is your fan clutch bad?

The E30 temp gage is stupid simple. it's a single wire thermistor (grounded at the block) and a very simple electric gage. So unless it's messed up, it's doing it's job. Whatever your fix is it's likely simple. If that's the one thing that makes you want to sell your E30 then you probably should. :(

[ADEN]

E30 temp gauge tells the real story. Not like most cars made after 2000 the needle sits always sharp in the middle and gives confidence. But the truth middle means (75 C to 100 C) lol.