High Temp Reading

[tommy50]

I Have A 535i E34 1990
Currently The Car Is Running With The Temp Gauge Showing Just Under The Red Mark Instead Of The Half Way Mark. It Is Not Actually Overheating Though. Any Idea's As To Why It Is Running So Warm????

[KC Ron Carter]

Check the engine driven fan clutch.

With the engine cold you can stop the fan with a rolled up newspaper.

With the engine warm you will NOT be able to stop the fan with a rolled up newspaper.

To change requires a thin 32 mm wrench and the threads are backwards.
CW loosens it, and CCW tightens it.

It will also explain why the tool kit has a set of pliers called water pump pliers.

Later,

[tommy50]

USED A NEWSPAPER ON THE FAN. WHEN COLD IT STOPPED, BUT WHEN THE TEMP GAUGE HAD GONE UP I USED THE NEWSPAPER AGAIN AND THE FAN STILL STOPPED. DOES THIS MEAN THAT THIS IS MY PROBLEM?????

DID A FEW CHECKS TODAY AND FLUSHED THE COOLING SYSTEM AND BLED IT. THE TEMP GAUGE IS STILL JUST OVER THE 3/4 MARK. I CHECKED THE THERMOSTAT AND THAT SEEMS OK. THE TOP RAD HOSE GETS WARM AT THE RIGHT TIME. I CHECKED THE HEATER IN THE CAR BUT IT WASN'T GIVING OUT WARM AIR AT THAT TIME.(i know it works as i found out the other day) I STOPPED THE ENGINE AND CHECKED THE COOLANT IN THE TANK. IT WAS STILL QUITE COOL WHEN THE TEMP GAUGE WAS SHOWING 3/4 MARK. THE ENGINE WAS WARM AND THE TOP RAD PIPE WAS WARM.
AM I RIGHT IN SAYING THAT WITH THE TEMP SHOWING 3/4, THE HEATER AND THE WATER IN THE COOLANT TANK SHOULD OF BEEN WARM????

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I DISCONECTED THE TEMP SENSOR FROM THE RAD WHILE IT WAS RUNNING AND THE TEMP GAUGE DIDN'T DO ANYTHING. I REPLACED IT AND THEN DISCONECTED THE TEMP SENDER UNIT WIRES AND STILL THE GAUGE DID NOTHING. DOES THIS INDICATE SOMETHING???

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ALSO, MY IDLE IS RUNNING AT AROUND 750rpm. IF I'M RIGHT IT SHOULD BE RUNNING AROUND 850rpm. WELL WHEN I DISCONECTED THE TEMP SENDER WIRES THE REVS DID GO UP TO AROUND 850. IS THIS RELEVANT TO MY PROBLEM???

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I WANT TO SAY A BIG THANKYOU TO ALL THOSE HELPING ME OUT WITH THIS PROBLEM. ALL HELP IS APPRECIATED. MANY THANKS

[KC Ron Carter]

If you can stop the fan when warm the clutch is needing replaced.

That is why you tested it.

Later,

[tommy50]

tested fan today by using another spare old fan i had. this fan however has 2 blades missing so it was only a test to see if it was the fan clutch. it was. however the temp gauge did still however go to the 3/4 mark. is this because of the 2 blades missing or wouldn't they make much diffrence?? or is there another problem?? while the engine was running, the engine seemed to be preaty cool but when i switched off the top rad pipe was really hot and one side of the rad was. the other side of the rad didn't seem to be hot. any help guy's would be a great help.

[tommy50]

Well, Here We Go Again. My Temp Gauge Is Still Running At The 3/4 Mark. The Computer Is Not Giving Me A Overheating Warning Though.



Have Now Fitted A New Complete Fan Unit.

Fitted Another Thermostat.

Been Told That If It Was The Water Pump Then The Engine Would Actually Overheat Which It Isn't.

And Bled The System.


Now I'm Completely Stumped. Any Other Idea's Anyone

[mechy1barry]

probably is your water pump.they are known for the impellors to come loose(its plastic) and not circulate the water.your symptoms are are classic for this problem/overheating/no heater.