Hot/Cold problem with my Fourtrak - can anyone help please?



I've got a Fourtrak 2.8 tdx, it's done 95k miles, was looked after by the owner before last then not looked after terribly well, now has come to me and I treat my cars well.

The problem is this, when I drive normally at speeds of up to 50 - 60 mph the car runs almost cold, if you put the heater on it blows out almost cold air.

When I tow my caravan up a hill my poor car gets very very hot, if I didn't stop and wait it would boil up, and there is a screaming noise rather like a belt slipping. It's had new fan belt etc and that did not cure the problem.

I want to get this sorted as it's such a great car.

Any ideas anyone?

Without a bit more info its d

Without a bit more info its difficult to say what the problem might be.

1. You say its had a new fan belt fitted...check the tension of the belt to make sure its been correctly adjusted when fitted.

2. If the screaming noise is not due to slipping belt (the steering pump belt will also 'scream' if its not tight enough), then it could be you have a knackered water pump (which also make a 'sreaming' noise when they give up the ghost).If the water pump is goosed the water will not be flowing through the radiator to be cooled and the engine will overheat.

3. The fan that cools the rad is of the viscous coupling type and you should be able to turn it freely by hand when the engine is cold.When the engine is hot (i.e. normal operating temperature) there is special oil in the coupling which expands and 'locks' the fan so that it turns with the engine thus cooling the water in the radiator.The coupling might be knackered thus the fan wont be turning and the water in the rad wont be getting cooled.

4. It could also be something as simple as a knackered thermostat and going by what you have told us I would change this first before doing anything else.

I suspect a knackered thermostat and a loose belt check all belts and change thermostat to begin with to see if that cures your problems...wont cost much either.


Hi, i'd also go for the thermostat. It's not unknown for a thermostat to break up & become jammed partly open. The themostat would flow water all the time but at a reduced rate so that when you're not working the engine hard it doesn't get up to temperature because of the constant cooling, but when you are working it hard then the partially blocked thermostat restricts the flow of water to the rad causing it to overheat.



Make sure you get a new thermostat gasket as well, you WILL need it, the old one will break up when the houseing is removed from the block..





If you are going to check if

If you are going to check if fan is locking when at operating temperature DO NOT CHECK IT WITH YOUR HANDS...use the handle of a broom...make sure you put the broom handle to the fan at an angle going with the direction of the fan movement ..if you understand what I mean.

Thank you very much, I will g

Thank you very much, I will get the thermostat changed and have the belts checked.

If I understand you correctly, you are saying that when the engine is cold I should be able to turn the fan by hand, and when it is hot I should not be able to turn the fan? - and if I can, the coupling is not working.

I'll let you know how I get on.

hot/cold problem on fourtrak

You have not said anything about the water level in the radiator, is it boiling/ pumping the water away?

Overheating Fourtrak

Well, thank you very much everyone who replied, much appreciated. I had the garage change the thermostat and water pump. I asked them to check the viscous fan, but I'm not sure whether they did or not.

Anyway, I took my caravan on a trip, the car did not overheat - it did get a little hotter, but I would have expected that as the caravan is big and quite heavy.

The heater is still a bit half-hearted, blasts hot air out of the windscreen vents but only warm out of the bottom vents. Maybe it's just a Fourtrak foible!

Thanks again for everyone's help.