just how hot is hot?

You dont want the water to boil as it then loses its ability to disapate heat. With 50% coolant a radiator should boil at around 125 degrees C

And they only work when 'wet'...(reminds me, must get around to fitting my low coolant alarm........purchased after a $6500.00+ mishap....

Hi Gossy.

I reckon there is more to consider than just the water temperature.

I found the following on Ryans Ryans Radiators website a while back:

Almost one third of the heat generated by the engine must be removed by the vehicle's two cooling systems.
That's correct your engine has two cooling systems.
(1) The top of the engine: the area around each cylinder in the engine block, the combustion chamber areas in the cylinder heads and the intake manifold, dispel heat through the engine's radiator coolant system.

(2) The rest of the engine: the crankshaft, bearings, camshaft, lifters, connecting rods and pistons are only cooled by engine oil.

The ideal operating range for engine oil is 82°C through 93°C. While operating within this range, the oil works as a lubricant, coolant, and cleansing agent in the engine.
Modern engines generally run with radiator coolant temperatures between 90°C and 105°C with oil temperature ranges up to 25°C HOTTER. In other words, when the engine is performing flawlessly, the engine oil is already overheating! Oil that exceeds 105°C rapidly loses its ability to lubricate and cool causing accelerated fatigue and premature component failure.

Makes you think.

Catcha
Eddy

good point about the oil. As mentioned about the expensive mishap, this is why I have fitted the gauge. I don't want to learn the hard way. By knowing if my cooling system is running well I can stop driving, fix etc before expensive repairs are needed.

Hi Gossy,

I was told by Nissan Aust. (for a 4.2 turbo) 118c is acceptable for short periods, ie: up ranges ect. I run a 1.1 rad cap. Don't know for sure if the same applies to 2.8 but can't see how there would be much of a difference.

Cheers Trevor.

If it’s Between 92 to 100 that is Fine if it’s going up to around 110 and above regularly when cruising or just driving normally then that is HOT in my book.

I think the factory temp gauge is Doing OK, there is no point in it registering below 50 as that is cold as far as engine Water temp goes.

Gossy, If it has been hot, sell it NOW....... I had one, go a tad hot, no problems, till I loaded it for a trip away, got about 100k's down the track and blew the head gasket big time. Expensive to fix. Do you self a favour, sell it while it is still OK

The total time it has been "hot" is probably only 20 mins (10 mins in Horracks pass and 10 mins on the freeway). As soon as the pressure of climbing was off it cooled straight away.
NATRAD only found 10% blockage of the radiator but the fan was not doing it's job so they fixed that (no oil). They mentioned that during the flush it was one of the cleanest engines they have seen for it age. Mechanically the veh is fine as far as I can tell. Anyway, I've spent too much money on it now to sell and start that process all over again.