Hi Folks, Hoping you experts can help us. We have a 2001 Vitara when you put it into drive the temperature gauge goes to hot but the engine is still cold.
The following is what has been done with it so far.

We checked the wiring harness and did a wiggle test on it. And did what you said by looking under the hood for movement when you put it in gear. There is not much movement. We also put a new instrument cluster in and it still is happening. We unplugged the coolant temp sensor and it started running different and showed a yellow check engine light. If it was shorting you think it would be interferring with this as well. The Suzuki dealer said they think it's the cluster and usually they have to put several new ones in before they find a good new one. We are not sure if it's a re-man or a new cluster. It came in a re-man box but the clusters didn't have screw marks on it where it mounts. So who knows.

Anyone ever came across this...with think it's a faulty instrument cluster.

Let us know.

Thanks and glad to find some experts out there

Did you try a different sensor. It's worth a shot. I always start with the cheapest stuff to check/replace then work my way up.