LR3 Running Hot

[hollywood009]

I have an 2006 LR3 4.4L
cold start is fine, temps are fine.
as soon as I start driving the temps rise, and stay high on the gauge.
after about 10 min of driving the temps quickly fall back to normal and the truck drives fine.

now my initial though was a bad thermostat, so I pulled out the thermostat out, however there is no difference. It is doing the same thing with out the thermostat, anyone have any ideas?

 

[doc5339]

Maybe take a look at the water pump?

 

[KeninNC]

I had a very similar issue.

Put a new thermostat in it.

When mine was running hot I pulled the thermostat thinking I would see a difference. I then flushed all the lines, replaced the pump and then replaced the radiator. Nothing worked. I did all this and still left the housing with no thermostat. After I did all this I put a new thermostat in and runs great.

 

[ggrupea]

I had the same issue on my Disco 1 some years ago. It was the heater radiator. Maybe this is the problem.

 

[grimmecm]

I would say replace the thermostat. I had that problem for about a week before my thermostat failed and stuck itself completely shut.