Hot temp/pressure issues; thoughts? 3.0i

[bigwinn]

Not just a big fat airlock stopping circulation? If coolant isn't flowing through the rad or past the temp sensor then it could be the block is getting hot on its own and creating extra pressure.

Its worth a check- I think when we replace the current expansion tank I'll run a hose through it too

Is fuse 61 in the engine bay? Cant see it on the fuse board

[PDJ]

So the rad fan in my car (an M car) the rad fan is off until either the air con is turned on and the fan runs at lets say 25% then as the temp increaces to the higher set point it then runs (lets asume) 100% it may control but other than puting the temp sensor in a controled temp I can not prove it. the fan runs unlit the temp drops to the lower set point.

I can activate the fan with my code reader to run at full speed and turn the air con on to test the lower speed.

The way mine is wired is there are 2 big wires that are live and negative feed that are live all the time (ign on) there is a 3rd wire that is the feed to the controler this apears to come via the temp sensor with is a NTC type of sensor so it is a 12v in and a veriable volts out to drive the fan controler

My 1 serries has 2 signal wires going to the fan controller and the two big wires
The temp sensor looks to fit almost every BMW they have made looking at realoem
picture of sensor and wiring diagram showing the NTC detail.

Capture cooling.PNG (133.41 KiB) Viewed 253 times

[enuff_zed]

Not just a big fat airlock stopping circulation? If coolant isn't flowing through the rad or past the temp sensor then it could be the block is getting hot on its own and creating extra pressure.

Its worth a check- I think when we replace the current expansion tank I'll run a hose through it too

Is fuse 61 in the engine bay? Cant see it on the fuse board

Says its a 60A in the 'Power Distribution' ??

[bigwinn]

So the rad fan in my car (an M car) the rad fan is off until either the air con is turned on and the fan runs at lets say 25% then as the temp increaces to the higher set point it then runs (lets asume) 100% it may control but other than puting the temp sensor in a controled temp I can not prove it. the fan runs unlit the temp drops to the lower set point.

I can activate the fan with my code reader to run at full speed and turn the air con on to test the lower speed.

The way mine is wired is there are 2 big wires that are live and negative feed that are live all the time (ign on) there is a 3rd wire that is the feed to the controler this apears to come via the temp sensor with is a NTC type of sensor so it is a 12v in and a veriable volts out to drive the fan controler

My 1 serries has 2 signal wires going to the fan controller and the two big wires
The temp sensor looks to fit almost every BMW they have made looking at realoem
picture of sensor and wiring diagram showing the NTC detail.
Capture cooling.PNG

Thanks Paul- I tried to fire the fan using INPA and nothing- I am now leaning (once fuses are checked) toward the sensor being faulty!

[bigwinn]

Not just a big fat airlock stopping circulation? If coolant isn't flowing through the rad or past the temp sensor then it could be the block is getting hot on its own and creating extra pressure.

Its worth a check- I think when we replace the current expansion tank I'll run a hose through it too

Is fuse 61 in the engine bay? Cant see it on the fuse board

Says its a 60A in the 'Power Distribution' ??

Seeing this one- not on the main fuse board though

F30A8E97-9908-42CE-A564-6CB61DA94FC5.png (146.02 KiB) Viewed 247 times

[enuff_zed]

Capture.PNG (110.3 KiB) Viewed 246 times

Could well be the same thing?

[enuff_zed]

Capture1.PNG (14.84 KiB) Viewed 243 times

[bigwinn]

Capture.PNG

Could well be the same thing?

Ah

Under the cover

Cheers

[enuff_zed]

Capture.PNG

Could well be the same thing?

Ah

Under the cover

Cheers

Never thought to look that far up tbh.

[PDJ]

Sensor £32 from GSF there is one in Lincoln

If you remove the undertray you can put the new sensor on the loom and dip it in boiling water to run the fan before you drop a load of coolant on the floor changing it

[enuff_zed]

Sensor £32 from GSF there is one in Lincoln

If you remove the undertray you can put the new sensor on the loom and dip it in boiling water to run the fan before you drop a load of coolant on the floor changing it

I love a clever check

[PDJ]

I love a clever check

You pick up a few ideas after 40 years in engineering maintanence

[PDJ]

Or warm it up with a small gas torch

Boiling water is safer

But if the high set point is 105deg you will not get water hot enough in Lincoln

[enuff_zed]

I love a clever check

You pick up a few ideas after 40 years in engineering maintanence

Same here, but always good to see something new that is specific to these cars.

[Johnstanners318]

Thanks for the input guys. Its been an interesting project so far. Learning a lot about the car from Bigwynn. Once this little gremlin is sorted the resto is should be almost finished.