Thread: Coolant temperature variation for V8

You know they make temperature gauges that stay at one indication , mainly because of questions like yours. LOL
Any engine will vary temperature all over the place.
My TD5 will usually sit on 82-85 but hits 97-100 on a big climb while towing . My Viscous fan cuts in at 92.5 . Also that is why the VC cuts in at mid nineties. Also in an RRC and I think later models the aircon fan comes on at 101(AFAIR)
My RRC used to sit on 85-88 but when turned off the heatsoak would bring it to 95-98 and up a really steep climb to 100C.
And the cooling systems were always spot on.
Regards PhilipA
Now if you had a diesel with an EGT gauge you would be even more alarmed as the temperature variations are enormous like 200C to 750C in a couple of seconds. I marvel how the metals can accommodate this.

normal

All seems normal to me.

They move around a bit,, but always corresponding to work/enviroment..
with the 82deg thermo I dont see temps in the high 90's at all now, no matter what i do.

I assumed this was the normal situation for this motor but only because of the peculiar recirculating system and dual valved thermostat. Interesting that TD5 numbers match mine exactly.
A bit strange that Pedro doesn’t see high 90’s with an 82 thermostat when I do with a 78 in probably cooler conditions.