I have a 2003 S type my wife was driving it a couple of months ago and it got hot. Sad thing she burned up the motor. We just got it back with a new motor and I notice that the heater gauge on the dash goes up to the normal half way mark but doesn't come down it is stuck. Maybe that is way she didn't notice it getting hot.

What do I need to replace so we can start driving it again.

 

Is it stuck on half way when ignition off?

 

The gauge goes go down when you shut off the car but goes right back up when you come back and start the car. But if you leave it over night in the morning the gauge doesn't go right up to half way. In the morning it seems to work just fine but after it gets warmed up it stays right at half.

 

Well if engine is warm the gauge SHOULD go up. What's the problem?

 

It sounds like it's working as it's designed to.

 

Well here I went to Walmart and the gauge was at half way. I went in side for about 30 minutes when I came back to the car and started it the gauge was already at half way it should have gone down a little. So then I left in the drive way for a couple of hours and tried again and it was still at half way. It didn't go down at all.

 

Check the coolant temp sensor. Unplug and plug it back in and see how it operates

 

It's quite likely not going to shift after 30mins. Quit worrying as it sounds fine.
If you want the actual temp, get an OBD tool or use ETM (see my sig).

 

Like many of us, you've discovered that the gauge sits at the halfway mark over a broad range of actual coolant temps.

That's the way Jag designed it. There's an ongoing debate whether it's a good thing or not.

 

I can park mine for an hour or two and the gauge will say it's up to temp on restart, as mikey says, it's not a true reflection of actual coolant temp, treat it as a warning light, eg if it rises above half way, it's overheating.

It was actually designed this way, a focus group said people were uneasy if the was lots of movement in a temp gauge. So what we ended up with was temp gauge that sits in the middle, reassuring us everything's fine, then.............. Boom, it suddenly shoots into the red in a matter of seconds and your engines toast.

 

Maybe it was an MS usability lab!

 

It's not a bug, it's a feature!!
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My gauge shows half-way (normal) when the coolant temp is still only 160F+,
Meanwhile, normal operating temperature is 190-210F, which is still at the 'half-way/normal' mark on the temperature gauge,

So as others are saying the 30 minutes you allowed it to cool isn't enough to really bring it down, and your gauge is probably working normally.

 

Thanks for the help I guess I just need reassurance that it is working fine so I am good to go

Thanks again

Rocky

 

+20 the Jaguar "idiot" needle gauge is working 100% fine.

I come out after an hour of driving to restart the car and depending on temperature and drive time before shutting the engine off - the needle is slightly below the half way point.

After 30 minutes of driving - still at the 12 o'clock position... My temp (live data) ranges from 198 - 215 degrees at full warm up. Needle at 12 o'clock position around 170 degrees and up...