E30 cooling system issues, need help!

[nzhaystack 0]

Hey everyone, I brought myself a 320i the other day and have realised it has a problem with the coolant temprature guage on the dash board. I have removed the cluster and i have double checked all wiring connections. When i turn the key to on the guage goes to cold and stays on cold, in saying that the guage is active but the sensor is f**ked!

 

Anyway i will shortly upload a video of the problem to get a better understanding

 

1. The car has no idea that the coolant it hot so it idles at 1.5 to keep engine heat (even when its hot)

2. The engine's electric fan (infront of radiator) never comes on because the sensor isnt working and the car always thinks it cold

3. The sensor i replaced didnt seem to make 1 difference at all.. There is still a spare wire (as shown in video)

 

 

Any Help would be much appreciated

 

[hotwire 352]

For a start - the temp gauge sender controls just that - the gauge, nothing else.

Sender is a single wire unit at the front of the engine

To test: Earth the wire & the gauge should go to high, open circuit - gauge reads low. If so - sender is faulty

There is the engine management coolant sensor sitting along side the gauge one - this one a two wire unit.

The resistance in this unit varies depending on water temp - high resistance when cold & low when hot - around 3k ish ohms cold & around 250 ish when hot

The fan sensor is in the radiator & the fan is also controlled via air cond circuit

[antil33t 90]

Also check the big connector on the side of the block under the intake manifold, they can go a bit coroded over time.

[nzhaystack 0]

For a start - the temp gauge sender controls just that - the gauge, nothing else.

Sender is a single wire unit at the front of the engine

To test: Earth the wire & the gauge should go to high, open circuit - gauge reads low. If so - sender is faulty

There is the engine management coolant sensor sitting along side the gauge one - this one a two wire unit.

The resistance in this unit varies depending on water temp - high resistance when cold & low when hot - around 3k ish ohms cold & around 250 ish when hot

The fan sensor is in the radiator & the fan is also controlled via air cond circuit

Heres the video, does everything look ok? I will do your checklist tommorow.

[huff3r 347]

Check the thermostat. Although it may seem that the coolant is hot, it may not be up to running temperature (which is VERY HIGH) and will not register on the gauge. I had a thermostat rusted open and had a similar issue, because that would explain it affecting both the computer and the gauge.

Running temp from memory is 90ish?

Mine was running at about 75ish, therefore not registering on the gauge (gauge only shows a small temp range, approx 10 degrees apparently.)

[nzhaystack 0]

Check the thermostat. Although it may seem that the coolant is hot, it may not be up to running temperature (which is VERY HIGH) and will not register on the gauge. I had a thermostat rusted open and had a similar issue, because that would explain it affecting both the computer and the gauge.

Running temp from memory is 90ish?

Mine was running at about 75ish, therefore not registering on the gauge (gauge only shows a small temp range, approx 10 degrees apparently.)

Thermostat could be likely as water has been sitting ins the car for a few months.. Where a bouts is the thermostat located? Did you have a look at the video and does everything look ok?

Cheers

Mitchell

[huff3r 347]

Im by no means an expert in E30s, so couldnt tell you anything from the video, but the thermostat is just inside the housing coming off the top hose from the radiator i believe. Should be the same place on your engine as mine, but not certain which hose to follow as I have a different radiator. Front passenger side of the engine however, just in front of the inlet manifold sorta area.

Sorry about the useless description..

[nzhaystack 0]

Im by no means an expert in E30s, so couldnt tell you anything from the video, but the thermostat is just inside the housing coming off the top hose from the radiator i believe. Should be the same place on your engine as mine, but not certain which hose to follow as I have a different radiator. Front passenger side of the engine however, just in front of the inlet manifold sorta area.

Sorry about the useless description..

Cheers guys!! I am fixing up some rust tommorow so i will look into the cooling system once that is complete I will update my status and any issues that come along the way

[_ethrty-Andy_ 2122]

Seems like the sensors ar to blame, anyone know which ones to change from this diagram? http://realoem.com/bmw/showparts.do?model=...hg=11&fg=35

All three are unlike the ones that were on my own M20, so i dont know which do what :S

Number 13 needs to be changed as one of the terminals is broken off lol, is that the one for the cluster?

Cheers, Andy/Mitch

[antil33t 90]

13 is for the cluster.

13 Remote thermometre sending unit 1 09/1985 62110788115 $28.76 Cat=N

[_ethrty-Andy_ 2122]

WIN will get that then and see what happens