How hot does your car run?

[Massimo]

Yes it should sit just below the halfway mark. I have had some experiance in this field. About a year ago my radiator hose decided that it would breakoff from the radiator, un-know to me this was the beginning of a eventfull 6 months.

So I replaced the radiator, and thermostate but the gauge sat above the halfway mark something was not right. Ended up that I got the 92 degree instead of the 88 degree. So ordered the 88 degree put it in and it still did not sit right. Tryed bleading the system and that but just did not want to go below the halfway mark. I decided that it was fine an just left it.

About a week later waiting in the Maccas drive through I look down at my gauge and the needle is in the RED!!!!!! of coarse I shit my pants and turn the car off. Apon inspection water was leaking from the front of the engine. It was the water pump, orded a new one from ebay australia as I did not want to wait for parts from USA, then got to work smashing the fuck out of the old pump to get it out. (Just a tip if the pump has never been changed be prepared to smash at it for about 1 to 2 hours with a small sledge hammer) Anyways replaced it and the guage still did not sit perfect.

So I ignored that for some time, then the termostate housing stated leaking. Found that I had missed a bit of old gasket stuck on the block which I had not cleaned off. Then the heater plate hoses started to leak so I did the heater plate delete. Then the heater core started to leak replaced that. Then the water pump started to leak again.

This time I orded one from pelican parts. Now this whole time the temp guage never went back below the half way mark. Now with my new pump it is perfect.

If there is anything I have to say about the cooling system on the M42 is if it starts to play up just raplace everything for a few hundred dollars it is worth doing once and once only, because it is a pain in the ass to bleed the system.

As for your problem I would say it is the pump from my experiance my problem the whole time was a bad pump. The three major parts that would affect the cooling system 9 times out of ten are Fan Clutch, Thermostate and Water Pump. If you were to just replace those three items you should be all good.

Hope this helps

[u3b3rg33k]

Kind of an update: i changed my thermostat.

No difference :( but the new bmw coolant seems to have made the engine run a bit smoother than it was with the crap coolant it had b4.

Ever heard of the placebo effect?

[Balleristic31]

Yes it should sit just below the halfway mark. I have had some experiance in this field. About a year ago my radiator hose decided that it would breakoff from the radiator, un-know to me this was the beginning of a eventfull 6 months.

So I replaced the radiator, and thermostate but the gauge sat above the halfway mark something was not right. Ended up that I got the 92 degree instead of the 88 degree. So ordered the 88 degree put it in and it still did not sit right. Tryed bleading the system and that but just did not want to go below the halfway mark. I decided that it was fine an just left it.

About a week later waiting in the Maccas drive through I look down at my gauge and the needle is in the RED!!!!!! of coarse I shit my pants and turn the car off. Apon inspection water was leaking from the front of the engine. It was the water pump, orded a new one from ebay australia as I did not want to wait for parts from USA, then got to work smashing the fuck out of the old pump to get it out. (Just a tip if the pump has never been changed be prepared to smash at it for about 1 to 2 hours with a small sledge hammer) Anyways replaced it and the guage still did not sit perfect.

So I ignored that for some time, then the termostate housing stated leaking. Found that I had missed a bit of old gasket stuck on the block which I had not cleaned off. Then the heater plate hoses started to leak so I did the heater plate delete. Then the heater core started to leak replaced that. Then the water pump started to leak again.

This time I orded one from pelican parts. Now this whole time the temp guage never went back below the half way mark. Now with my new pump it is perfect.

If there is anything I have to say about the cooling system on the M42 is if it starts to play up just raplace everything for a few hundred dollars it is worth doing once and once only, because it is a pain in the ass to bleed the system.

As for your problem I would say it is the pump from my experiance my problem the whole time was a bad pump. The three major parts that would affect the cooling system 9 times out of ten are Fan Clutch, Thermostate and Water Pump. If you were to just replace those three items you should be all good.

Hope this helps

Thanks a ton!

Ever heard of the placebo effect?

dont ruin my fun ;)

[Balleristic31]

Update: bled the coolant even more today.
Dropped the temp SIGNIFICANTLY.

[u3b3rg33k]

Cool. Another thought. Since I have developed waving temp gauge syndrome, I check my head and thermostat housing temps with an IR temp gauge occasionally. They're never out of spec, even when the gauge says otherwise (most of the time, a hard whack will return it to normal, and if not, perhaps peg it).

It's a good way to verify temps.

[Balleristic31]

Ugh. Went back up again today.
Thinking it may be my gauge as the needle does bounce around quite randomly sometimes...

[Balleristic31]

Bump from the grave

Something is wierd w/ this thing.
When im low on oil, the temp gauge reads cooler and almost normal. Once i add more oil to get it up to reg level, the temp gauge reads hot again. :loco:

Idk what could be causing this. Any thoughts?

[u3b3rg33k]

I have no doubt anymore: Bad grounds. Most likely the ones in the cluster itself. That's a classic sign right there. Do your cluster or OBC lights dim slightly in rhythm with the blinkers(most easily checked at night with the lights not at full brightness)?

Have I mentioned how much I despise common ground systems? It's FTL.

[dkbmxer002]

yea i agree with u3b3rg33k, it is probably a ground or maybe the sensor...

[grantlacey11]

That doesn't sound right.

My '91 318i is generally between the blue bar an 1/4. Hottest I've seen it get was half way between 1/4 and 1/2, and that was in stop and go traffic on a 35-ish*C day with me driving like a jackass.

now thats way too COLD

[u3b3rg33k]

yea i agree with u3b3rg33k, it is probably a ground or maybe the sensor...

If it was just the sensor, it wouldn't change depending on the oil level sender. Any sensor that only has a single wire run to it is not trustworthy once the grounds aren't in proper condition.

[dkbmxer002]

If it was just the sensor, it wouldn't change depending on the oil level sender. Any sensor that only has a single wire run to it is not trustworthy once the grounds aren't in proper condition.

really? i am trying to trace an issue with mine, it is going straight to maxxed hot once i put the key in (even after sitting for days...) and before i even turn the car on. the grounding nut on the back of the gauge cluster is good and tight so i figured maybe my sensor went bad when i ran it too hot. i don't know what else to check. any advice?

[u3b3rg33k]

No, because I haven't gotten to it yet :(
But it is affecting other systems as well, like my auto-dimming interior lights.
What I'd like to do is run a separate ground bus straight off the negative terminal. None of this grounded chassis crap.

[dkbmxer002]

good luck with yours! mine is only tied to my coolant level.. so i am hoping swapping the sensor fixes it...



i have an m42 so both sensors are under the intake and i am too lazy to do it so far... i have tried nearly everything except that... i wanted to try and follow the wiring from the gauge all the way to the sensor but it seems very hard to do so.


i personally hate the wiring of our e30's.

[Eecen]

now thats way too COLD

LoL... Yeah I know. Get fairly poor gas mileage too, although I drive the thing w/ a heavy foot.

I had planned on doing a swap, so I didn't really care as long as it ran..but since I'll be keeping it m42 for awhile we'll see if a new water pump/thermostat will make any difference in the spring.