Thermostat problems

[TAZMAV]

I'm looking at swapping my GQ TD42 for a 2.8 GU but it has an over heating problem which I've tracked to either a faulty temp sender or a stuffed thermostat. My problem is I'm not sure where the thermostat housing is, I haven't had time to have a proper look for it as yet but A quick look while running the other day didn't see it in the normal spot. Can someone help me out?

[happygu]

Keep the GQ, as it could be a head issue with the 2.8, or at the very least a gasket

Mic

[TAZMAV]

The head on the GU has been checked and each cylinder has been pressure tested so it's neither head nor headgasket, It been tracked to either the sender or thermostat. It only does it once or twice a month

[Stropp]

no way would i swap or buy a 2.8 over a 4.2 no matter how many k's on the 4.2!