AU XR6 Overheating

[PAS]

Got a problem with AU3 XR6 over heating. Just put LPG on and now its overheating. It has new heavy duty radiator in it and a new water pump and thermostat. Wot could it be??? Please help.....

[stiddy]

Make sure the Thermo's are working.. and spinning the right way.

Sometimes after a radiator swap, the thermo's are forgotten to be plugged back in.

[GK]

Check to make sure the thermos are actually hooked up!

Sounds funny, but someone else had heaps of overheating issues and the thermos had been left disconnected after some work was done on it.

GK

[AU:PROJECT:UTE]

Stupid little thing really but make sure all the air is bled from the cooling system after replacing the water pump and thermostat. That could be what is doing it if it wasnt bled properly.
Take your coolant cap off and run the engine till the coolant bubbles and that will get the air out, well thats in the older style cooling setups without a header bottle, someone with more knowledge could correct me?

[PAS]

Thanks for your help, but the thermos are working correctly and the coolant has been bled properly by a mechanic. What else could it be. We have put different coolant in, to see if that made a difference. It didn't make much, but its still overheating.......please help :

[JC]

Originally Posted by PAS

Thanks for your help, but the thermos are working correctly and the coolant has been bled properly by a mechanic. What else could it be. We have put different coolant in, to see if that made a difference. It didn't make much, but its still overheating.......please help :

If it's got new coolant, and the thermos are working, there's only 3 things left:

1. Blocked radiator (unlikely)
2. Seized Water pump (but you should be able to hear it squealing)
3. Stuck Thermostat - if it's stuck in the closed position, you would only be getting a trickle of water circulating, hence the overheating.

If it's none of them, then perhaps the thermo fan fuse?

[XR6-VCT-2000]

Is your fuel pump still pumping fuel into the fuel injector rail when running on lpg ? (to keep the injectors & rail cool )... If not - this could be causing overheating / and more damage to come / if that is the problem .

[PAS]

New Radiator
Two New thermostats
New water pump
New coolant, that is bled properly
Thermo's are working correctly
What else could it be??????

[Au2falcons]

Why was the water pump changed?

When the old one was removed, was the impeller still intact, seen cases where the impeller falls to pieces and blocks passages.

[JC]

Originally Posted by PAS

New Radiator
Two New thermostats
New water pump
New coolant, that is bled properly
Thermo's are working correctly
What else could it be??????

There must be a blockage in the system somewhere. Or the thermo fans aren't working. Are you 100% sure they are connected? To make sure, disconnect the electrical plug on the drivers side of the thermo fans, and reconnect. Idle car until thermos kick in (good luck getting them to do that in winter, but if it's overheating, it should happen easily enough).

[XR6-VCT-2000]

Have you actually only just had it converted to run gas aswell ? ,
or did you mean

'just put LPG on' .... as in that you just switched it over to gas again recently after running it on petrol for a while ?

[nitroman]

If the only difference between pre/post overheating is your lpg installation I would be thinking your gas/air mixture is too lean. You can jet the gas like on a carby. I would hit up your lpg installer about this and if they know nothing try somebody else. It's possible they have fitted a universal setup that would be fine on a taxi, but on an xr that breathes a lot more it could be running to lean. Fix it now before you melt pistons.
Of course never discount a blown head gasket making it hot.

[AUXRVIII]

Is the lower radiator hose kinked or sucking in? Is the cyl head temp sensor properly connected? Is the engine actually over heating or is it a faulty guage, temp sensor or faulty wiring?