platypus149

I have a '73 911T that gets up to around 250°F pretty regularly. (Once driving it gently on a flat road on a 95 degree day and once driving up a canyon on a 70 degree day - wasn't driving particularly hard but I did climb 3000 feet in less than 10 miles.) Seems like it used to run about 210°F even on the hottest days when I lived in the humid midwest close to sea level, but now I'm in the desert at about 4000'. Is this something I should be worried about and need to look into installing an external oil cooler, or is this acceptable?

Thanks for any advice.

pu911rsr

Check the oil cooler to make sure it's clean and has proper airflow going to it. Carbs, CIS MFI- car may be running lean as well.
Phil

TerryShugart

My 75 has an SC fender cooler (loop coil) and I adjust the CIS to run the plugs brown to tan which is on the rich side. I live in SW FL and my temps are around 210-220 on a typical 85 degree day. I would suggest you look at the plugs. If they are white or light grey the induction could be too lean which would mean more heat.
Terry
75 911S

Steve Weiner-Rennsport Systems

250 deg F is FAR too hot, especially for a mag-cased engine.

Check your ignition timing, fuel mixture to be sure its at spec. If the oil cooler on the engine is all dirty, it will compromise its effectiveness and should be cleaned. You'll need to R&I the grey duct on top of the fan shroud to gain access.

r911

also remove the rat nesting material in between the grey duct and the top of the fan shroud...

theiceman

I'd also pull the stat and have it checked.

rusnak

How many miles on the motor? About how many miles ago was it running at 210 F? Does it consume a lot more oil?

Mark78

I would suggest you look at the plugs.

TerryShugart

I forgot to mention this yesterday but higher altitude means less dense air with the result being that the mixture would be richer. That said the same would be true for the air flow through the engine at 4k feet. Less dense air could cause the temp to rise. If all else is up to snuff a thought may be to change the fan pulley ratio to increase the air flow and provide more cooling air.
Terry
75 911S