E30 Zone

Got a problem with my temp gauge not moving out of the blue.Recently done a timingbelt change along with water pump,thermostat, tensioner,coolant and oil change. Bled the system took her for a good 40 mile run and was better than ever with the temp at the quarter mark .Yesterday i changed the plastic screen on the instrument cluster and have since had this problem.Seem to recall something about a screw(earth?) that can come loose behind the cluster ,would this cause this and if so does anyone have a pic of it.Also is there an easy way to disconect the wires from the gauges,dont really want to use brute force.

Wires now disconected and can,t see any loose screws,any ideas?

does it not move at all now?

ballin,not now ive disconected the instrument cluster Took it for a quick run after topping up coolant slightly but still not moving out of the blue,but yes the needle does move.

Just thought id point out that the heater works spot on.

Loose nut makes the gauge read slightly high.
Most probable explanation is you've bent the needle.
To remove the white and blue plugs from the cluster, lift up the black plastic bar around the middle with a small screwdriver.

Noticed last night that car,325i is also idling at 1000rpm,got a nagging suspicion that ive pulled a pipe of somewhere.Will take a look tonight.

Right just had quick look and found the white sensor?not connected properlybut while im here has anyone got a pic of what order the blue, white and brown sensors are connected.

Clipped the white sensor back on and ran her for a bit, does seem to be running smoother but still idling high and temp still not moving out of the blue.Coolant hoses seem very hot too but saying that i never took much notice of how hot they got before.

Sorry if ive confused anyone but after reading this myself think id better point out that im talking about
the white,brown and blue sensors near the thermostat now not connctors on the instrument cluster.Brian had a look at temp needle but doesnt appear to be bent.

maybe its just packed in..Try changing the cluster with someone elses and see if there temp guage goes up.

could also be a dodgy thermostat..Ive had thermostats bought brand new for various cars and a few of them have been faulty.

Is this a UK M20 engine? What white sensor?

Its not the cold start thingy is it ????

Part 16

http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

[quote="Brianmoooore"]Is this a UK M20 engine? What white sensor?[/quote
Yes def a uk engine, on mine there are 3 of these, looking from drivers side of engine firstly from there is a white plastic sensor then a blue one(temp?) and lastly nearest to thermostat housing is a brown one(ecu?)

Brown one is temp gauge (short wire to earth and temp gauge should go to full hot), blue one is ECU.
What year is this engine?

very early M20B25 by the sounds of things......

1/8/86

Early one then. White sensor possibly is a cold start injector thermostat then, but I've never set eyes on one so early.
Brown sensor is still your temp gauge sender though.
If the car's running cold, then it's a thermostat problem.
If the car just thinks it's running cold, then it's a gauge circuit problem.
Fairly simple circuit. Thermistor (brown sensor), earthed by being screwed to the stat housing (possibility here, I suppose. Check for zero ohms between the stat housing and the engine block). Single wire from the sensor, through the engine loom plug and socket on the bulkhead to the instrument cluster.

Have now replaced temp sensor and temp gauge and car is running fine.Strangely the revs have also dropped a bit but still slightly high.Will now swap the TPS ,got it this am Eko,cheers .Saw a thread on here about drilling a small hole in the TPS to let any oil drain out.Have i got that right?.Big thanks to all who helped,Brian you were right
the temp gauge needle was bent just could,nt see it till i removed it from the cluster.