Over Heating Problem

porsche
911

#1

I have a 1983 911SC Porsche that has started to over head, not in stop and go traffic only on the hwy under a load, will not cool down on it’s own no matter what you do, I have to turn it off to cool it down, took it to a very reputable Porsche repair shop in Seattle, $840.00 later he could find nothing wrong, thermostats ok, no vacuum leaks, fuel injection ok, nothing on top of the motor causing heat, it has ran cool for 4 years and all of a sudden the last 4 times I took it out I had to pull over and turn it off to cool down, it will not cool down no matter what

you do on it’s own. What is odd is it runs cool around town in traffic if only over heats when you get on the hwy in 5th gear at 60 or 70, under 3000 RPM, if I punch it a couple times under a load it just starts heating up. Any help would be greatly appreciated


#2

When was the last time the water pump was replaced? The impellers may be worn or broken. At low rpm’s the water pump may be marginal but at higher rpm it may be failing to move the coolant properly under load.


#3

Air Cooled


#4

I forgot about the rear engined 911 being aircooled. The only experience I have had with a Porsche was in 1984. I convinced my wife to let me buy a 944. It was a beautiful car but it was woefully underpowered. I sold it a couple of weeks later.


#5

Now there is a man, calling any 911 underpowered. You never had a Sunbeam Imp (1,200 cc engine, four passenger car. Three high school students could lift it.


#6

To make things clear…I said the 944 was underpowered. It was. It was a 5 speed, normally aspirated model with a tiny 4 cylinder. I had a “bug eyed” Sprite back in high school. I found it on the gymnasium steps more than once thanks to some members of the football team.