Any Cooling System Specialists Here?

[Ruud]

Here goes...

I (also) have a 2000 Range Rover 4.0 V8 (I know, I know :) )

The problem is that the thermostat won't open for some reason. The t-stat is brand new and checked.

The t-stat is located at the bottom of the rad so not in the usual top engine area.

Here's a pic of the system and flow

The engine will overheat when driving, but not on tickover - no matter how long I let it idle.

As said: t-stat replaced and checked, expansion cap replaced, system is 'burped'

Radiator flushed - all fine. heater matrix flushed - all fine.

I'm taking off the water pump tomorrow to see if the impeller is sheared of...... other than that, I'm pretty much out of ideas.

Anyone?

[Redsteve]

Hi Ruud,

I know this is a long shot but have you checked that the rad is clean on the outside?

I do a bit of off-roading and I get similar symptoms to what you have described when the rad fins get full of mud. It's fine on tickover and driving at 20 MPH all day but overheats within a few miles of normal driving.

Maybe you have something blocking the air flow through the rad.

I hope this helps.

Steve.