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DISCUSSION => Electrical => Topic started by: johna on April 18, 2011, 07:01:34 AM

Title: Temperature gauge fluctuating
Post by: johna on April 18, 2011, 07:01:34 AM

My 318is (E36 series, M42 engine) has recently started with a problem with the temperature gauge. It stops working intermittently and either goes all the way down into the cold or fluctuates from cold to actual running temperature. I am confident that the problem is with the gauge and that the engine is running at the right temperature.

My question is, is it most likely the gauge, sender or wiring?

Has anyone ever had an intermittently faulty sender?

Has anyone had this problem before?

Thanks.

Title: Temperature gauge fluctuating
Post by: DesktopDave on April 18, 2011, 07:09:22 AM

I had a similar problem with my fuel gauge once.  On my e30, the fuel and temp gauges both have a nut on the back to retain them...if that's loose it'll have intermittent contact and might act as described.  I'm not as familiar with the e36.

I'd also test the temp sender for ballpark resistance figures.

Title: Temperature gauge fluctuating
Post by: SiGmA_X on May 22, 2011, 06:21:03 PM

Thanks Dave, my eta has this issue. I'll have to pull the cluster and look for loose ish! Thanks!

Title: Temperature gauge fluctuating
Post by: DesktopDave on May 23, 2011, 07:22:44 AM

Definitely.  Though everyone calls it a "grounding nut" I'm guessing that it's just a mount.  If it's loose the contacts won't work well...so the gauge won't get power from the cluster to amplify the faint signal from the sender.

If you determine that the gauge is bad, all e30's will swap with the M42 coolant sensor.  All my clusters are VDO, so I haven't attempted swapping MotoMeter cluster components with VDO but they look the same to me.