SLROC Forum

Alrite guys, as the subject title says we've got overheating problems, the expansion tank was leaking so I've changed that now I've got the weirdest sh** going on, it will run sound for a while then the temperature will suddenly shoot up and the heater stops working at that point it can go up into the red for a bit and then it will drop back down and the heater starts working again.
Got me puzzled as there aren't any leaks, my next course of action (once I get some gaskets) will be to remove the thermostat and have a look at the water pump but it puzzles me as to why the problem seems to come and go, so any suggestions would be gratefully received.
Cheers

My guess is that there is air in there - hence the heater stopping. Start by draining the lot and refilling maybe ?

mine did that 300tdi head gasket was gone at the back corner, check it before its melts the head

The coupler unit behind the fan starting to fail will cause this.

Well I've tried bleeding the system repeatedly to no affect, I can drive 15 or 20 miles before the temperature rockets, and I don't know how to check the coupling on the fan but it spins, though there is now a nasty squeaky noise coming from around the water pump area so may be the pump is on the way out. Still not getting much heat out of the heater and I've got a leak from the bleed screw to now but don't want to over tighten it as the threads look proper dodgy, I suppose it's a tube of instant gasket and have a look at the pump.

Is there any play in the shaft that the fan is connected to? If your water pump is squealing then I'd suggest the pump is indeed on its way out.