Westerbeke 30B 3 Temp gauge gone wild...

[LeftWinded]

Ordered a thermostat a couple of weeks ago and installed to make sure it wasn't the problem. Works fine as far as I can tell.

The problem is that right from a cold engine start my temp gauge swings wildly. It will jump to off the scale, then drop to whatever the real temp. is, then back up again. Have anyone heard of this? Does this sound like a bad water temp. switch, a bad gauge, or a grounding issue to you? Whatever help you can give me would be appreciated.

Not sure if it is related or not, but my oil pressure gauge just stays peaked now as well.

Thanks,
Roger

[motion300]

My guess would be the wire

[JimsCAL]

Most probably an intermittent ground in the wire running from the sender to the gauge. Since it does read correctly at times, it indicates the sender and gauge are OK. The max reading on the oil pressure gauge indicates a similar problem - just not intermittent.