Gremlins on m3 1st startup.

[bigbird76]

Hey all

Car is 1988 m3

Just a few questions if anyone can point me in the right direction

I have successfully managed to start my engine which has been sat for 4 1/2 years whilst my car has undergone a full restoration.

On initial start up the car did not want to idle and was not firing on 4 cylinders I narrowed this down to sticky injectors which I have just had cleaned using ultrasonic cleaning. The car then started ok but was idling a bit rough until it had warmed up a bit. Coolant was filled at the same time and filled with about 9 litres of water and anti freeze coolant.

The last few days I have been tinkering with the car, The temperature gauge moves a little when I turn on the windscreen wipers and when I turn the heater fan speed from 0 to 1 the temp gauge goes up, and from 1 to 2 it goes up even more, This is the same for speed 3 and 4. The heater pumps out nice hot air so I presume the heater is working.

This is where I get worried, With the car started and warmed up for 5 mins, With the heater fan on position 0 the car settles on about half way on the temp gauge but turning to position 4 then the temperature rises up into the red but not off the temp scale. I am too afraid to leave the car idle anymore as I do not want to damage the head and I do not trust the temperature gauge at the moment or if I am getting true readings from it.

I have checked the earth points on the engine which seem ok and the earth points under the dash all look ok, I checked the plug connector from the heater to the loom, This also seems ok.

I am guessing I have a ground/earth problem, I also unplugged the 1 pin temp sensor by the coil and grounded to test and the gauge went off the scale so I believe I have a connection there ok. I have read that the temp gauge can play up with a loose nut on the back of the cluster but I have not tried that yet I am not sure if it is associated with my problem.

I need to get this working correctly before I can move on.

Also how can I check if the thermostat is working correctly I have a new one from Kirby(C3) The water is hot on the top hose and cold on the bottom hose, I am guessing the water enters the rad from the top hose and comes back up through the thermostat from the bottom of the rad?

Can anyone suggest anything I need to check or explain, I am not the best electrician.

Thanks in advance

Leigh

[Brianmoooore]

You are right that this looks like an earth fault, and by what you describe it would be at the main earth point behind the dash. If all is OK there, then the only other thing I can think of, although unlikely is a problem with one of the joints where brown wires splice together in the loom in the under dash area. Trace the path of the brown wire back from the heater fan to the earth point.

[bigbird76]

All fixed Brian

Re-tightened the nut under the clocks and checked the nut on the cluster all good now.

Temperature just sitting half way.

Leigh