I have a 1995 XJ 4.0 petrol. There are 5 lines on the engine temperature gauge. Line 3 is the midway mark where the temp gauge typically sits. I drove a round trip of 360 miles in a day recently. On the way back home on the highway I was glancing at the gauges and noticed the engine temp gauge was visibly increasing to just over the half way mark on the gauge, and then immediately dropping back to a point midway between the 2nd and 3rd lines on the gauge. It would then repeat this visible heating and cooling cycle over say a 1 mile stretch. It did it the entire way home, and since then I have noticed it happening reguarly on any trip I do.
When I stopped moving, the gauge seemed to remain steady, so I'm wondering what might cause this?
When I stopped moving, the gauge seemed to remain steady, so I'm wondering what might cause this?