What coolant temp sender (for the gauge?)

[nick526]

I've got my M30 swap up and running but I've noticed that the temp gauge never moves much, even when the electric fan kicks on. I'm using the m20 harness with all the M30 sensors/senders.

The m20 I had before also ran pretty cool (1/4 or so,) but would climb to the halfway mark while stopped in traffic on a hot day. So I'm pretty confident that the gauge and cluster are functional.

I've read that the m20 sender is "matched" to the temp gauge in the cluster. Does anyone know this to be true? Should I swap my M30 sender for an M20 version? I'd hate to be running too hot and not even know it.

[yert315]

put the brown sensor from the m20 in there. The sensor is specific to the car, not the engine.

[porschelou]

We also added a VDO sensor and gauge in our car. I like having two temp gauges - just in case one dies. We also put the oil temp gauge in - helps tell if your engine is getting hot. We lost coolant during a race so the temp sending units had no fluid touching ( needles never moved) them so the motor seized. The oil temp sensor is a double check..