Author Topic: Instrument cluster (Read 3546 times)

Vladi · « **on:** November 03, 2007, 02:17:20 PM »

I've been having this problem a long time and i'm sick of it.
My water gauge acts funny. Until the 1/2 mark it rises normal but then it keeps on climbing until the next mark after 1/2 (all this is hapening with the car moving at 48 degrees F). New tropical version radiator, the thermostat opens.
After it passes the 1/2 mark everytime i step on the brake, use the windows, turn on the rear window defroster, turn headlights on/off, basicaly anything electric it jumps closer to the red zone.
Measured the water temp in the expansion tank and it read 176F when the needle was a little past 1/2.
I changed the water gauge, same thing, cleaned the two prongs, tightened the nut, nothing. Measured the SI board batteries, they're fine, 3.0V each.
Could a faulty instrument cluster board be at fault? I didn't get to test another one yet...What do you say?

Thanks!

FL318i · « **Reply #1 on:** November 03, 2007, 09:20:27 PM »

my car does the same thing, but my problem is on a red light at idle cause my aux fan switch doesnt work did you check on this???

Vladi · « **Reply #2 on:** November 04, 2007, 02:20:32 AM »

My aux fan works.

gearheadE30 · « **Reply #3 on:** November 04, 2007, 01:40:33 PM »

Did you check the ground nuts on the back of the cluster? If they are loose it can do all sorts of wierd stuff. Do you have any other electrical problems?

Vladi · « **Reply #4 on:** November 04, 2007, 03:18:29 PM »

The nuts are tightened firmly. I don't have any other electrical gremlins.
I'll just try out another whole instrument cluster this week and see what's going on.:confused:

DCColegrove · « **Reply #5 on:** November 04, 2007, 04:16:42 PM »

Hmmmm.

These systems can have air in the top half of the radiator and stay that way indefinitely causing them to run hot. (only half of the radiator works).

Is the top frame of the radiator cool enough to touch?

This is what I'd do first bleed the cooling system...

Use this procedure:

1: Remove the AUX fan switch and fill until coolant mixture is running out there. Replace switch.

2: Remove bleed screw and continue to fill right to the top (running out of bleeder and at the top of the tank).

3: Start the engine rev to about 2500 with the cap off (there should be a stream of coolant squirting from the "radiator side" of the reservoir.

4:Spin on the cap while it is still at 2500.

5: Turn on the heater and rev the engine until you are sure that it is blowing hot air.

If this doesn't solve it you need to get a direct reading of the coolant (the reservoir isn't the spot)

The best way is with a handheld pyrometer aim it at the thermostat outlet side... this should be close to the engines operating temp.

If this doesn't get it let me know we'll get into other M42 cooling issues.
(there is more than a few)

oldtimer · « **Reply #6 on:** December 15, 2007, 10:10:23 PM »

I have this problem and I was looking and even replace the sensor. When I decided to removed the cluster and planned on changing the temp gauge with a known good one, when took a socket to removed the nut that hold the gauge againts the cluster it was loose. Tighten it up and re-install cluster never had any problem with temp again.