4 replies to this topic

[blackbelt1990]

Hi guys, got an mpi problem

Car has had a new rad, new expansion cap, new fan sensor and new thermostat.

The top hose doesn't build up any pressure and the expansion tank boils over. Aswell as this, the fan doesn't kick in but it has a new sensor and works fine when attached directly to the battery.

Can anyone help? Please!

[blackbelt1990]

Quick update as I've had a play, if I join the wires of the relay together, the fan works.

If I unplug the brown connector and turn the car on, the fan doesn't do the fail safe kick in.

I'm assuming a need a new relay?

[blackbelt1990]

Right, fan now works with a new relay. The whole system just exploded through the cap, which is new!!

[cian]

Is the engine reading too hot?

[eero]

I'd start with the thermostat - sounds as if it does not open and there is no flow back to the radiator, thus the the aux fan does not kick in as the coolant in the radiator has not reached the temperature. And the rest of the system would become extremely hot as the coolant isn't flowing and cooling.

 

Did you use any silicone to seal the thermostat housing - too much and the thermostat might have been sealed shut, or it might be a faulty unit - Haynes has a section on how to test it.