That's great to know regards the potentiometer folks


I might have got to that already had I not been dealing with another round of failed cylinder head drama

The problems started right after the turbo swap. When that job was done I went back to an 88oC thermostat, but the housing didn't seal properly after it was put back together, I think due to some corrosion on the surface that mates up to the rubber seal. I took the truck on a long road trip more or less the next day (bad idea probably) and it dropped just shy of a litre of coolant. I only realised when we arrived and I noticed the coolant temp notch up a couple of degrees when I pulled up. The viscous fan had locked up a lot but because it was also the first big trip since I got the intercooler running, I put it down to the IC radiator dumping extra heat on to the fan hub. I fixed up the corrosion and got a proper seal for the trip home and things seemed ok.
Next trip the fan got a bit eager again and this time I was immediately suspicious, popped the hood and the overflow tank had shed coolant all over the show.
Anyway, this time I am going with an OEM head for certain! Not sure if the previous one failed (other that it being a s*** design already) due to having air in the cooling system or because it was an aftermarket head of inferior quality or both (also had rough starting problems ever since it was installed) but it only lasted 40,000kms. For the majority of those kms the cooling system has been WAY better than stock and I've never run post turbo EGTs above 1000F so as you can probably imagine it was a bit of a bugger to have this happen again. The new head will be this truck's fourth and it hasn't even hit 200,000kms.
I figured, in for a penny in for a pound so hunted around and found replacement hoses for the entire cooling system, cleaned up all the rust on the metal coolant pipes and repainted these and the valve cover while I was at it. This truck certainly ought now to be set up extremely well to avoid another premature failure!! I should have it back in the next few days...