Thread: 82° Thermostat in a 4L V8

Originally Posted by ozscott

Yep Pedro I had the same experience. ..they dont like OAT and have seen damage caused by it. They have had a good run wth green.

Cheers

When they put in the green, is it actually glycol or is it the green OAT? Apparently there is a green OAT which is also compatible with glycol unlike the red OAT.

I have a new radiator on the way and when I install it I am going to change to glycol. Its cheaper and I still reckon it works better.

No its glycol based matey

Cheers

I've been using the Penrite Purple OAT type coolant along with Redline water wetter without issues for about 18months now. With both the old system and now in the new post repair system (new rad, hoses and thermostat).

Temps now 87deg constant, maybe hits 90 sitting at lights on a 30+ day but cools back within a few hundred meters.

Further to this, and as queeried above, I now know that the cold start/hot running "tune" kicks in at 55degC so even the cooler thermostat will have it running above whats required for normal operation.

Over the last week with temps into the 30's and doing a lot of city driving with ambient temps of 30-32 degrees in direct sun and traffic it sits on 88.5 and 5min of getting on the freeway gets it back down to 84. Average winter temps seem to be 87.

As a comparison my 4.0 with new standard 'stat radiator, hoses, engine flush an new gaskets is typically sitting at 88-91 driving on injected LPG and up to 94/95 in heavy traffic on 38 degree day. Towing a 2 tonn load makes virtually nil difference so there is plenty of cooling in reserve. I dont see those temps as stressing the engine at all. All they do is possibly/probably make for a more efficient fuel burn and better emissions.

Cheers

Personally, and it's a me thing given the history of these engines & my luck with overheating I'd rather keep it as down as possible. Doesn't effect cold start to hot running switchover, haven't noticed a change in the (woeful) consumption. Mine's also a 4.6, if there was ever a difference in the running temps between capacities.

Mate you may be right. I really dont know. Usually lower temp means greater longevity (provided it is not running cold and yours isnt of course).

Cheers