Help! JK Diesel Overheating at High Speed

[Jonye]

Basically the car runs fine up to 60km/h. As soon as I get up to 100km/h the temp goes to 106 celcius and about a litre of coolant is spat out of the expansion tank, leaving it almost empty.

My mechanic wants to do a test on the radiator but I'm thinking if he's pulling it out anyway it's best just to spend the $250 extra and slap a new one in there.

Is there any other potential solutions I should be looking at ?

 

[BLACKJKU]

Sounds like it could also be a head gasket going bad, have them test the coolant for signs of exhaust.

 

[Jonye]

Sounds like it could also be a head gasket going bad, have them test the coolant for signs of exhaust.

Yeah they tested this and no exhaust gases. Plus it can idle all day without heating up.

 

[BLACKJKU]

Yeah they tested this and no exhaust gases. Plus it can idle all day without heating up.

Has the radiator cooling fins been cleaned or blown out, alot of leaves and bugs and plug it up.

Maybe it needs a new radiator cap, or thermostat?

 

[mrjp]

My mechanic wants to do a test on the radiator but I'm thinking if he's pulling it out anyway it's best just to spend the $250 extra and slap a new one in there.

I would go with a complete system flush and new antifreeze along with the new radiator & thermostat. Your cooling system would be good then. also check your clutch fan also.