Cooling issues - can't diagnose

[Carl Jarrett]

Been having some cooling issues lately on our 2008 Cayenne GTS. It has a replacement radiator after the last one leaked. It's also had a new water pump and new thermostat, and new e-fan. 

 

The issue we're currently having is coolant isn't leaking, but coolant light came on when my wife was driving it. She brought it home, I suspected there was an air bubble, so filled up the coolant and took it for a drive. I was idling in traffic and started to get slightly over halfway on the temp gauge so I stopped and let it cool. Drove it again for 30 minutes straight in 16-17deg C temperature without getting stuck in traffic and i t never got hot. Once I got home, I let it idle and eventually it started to get hot again. Each time I shut it off, the e-fan's aren't turning on, either of them. 

 

Is there a way I can diagnose if it's the e-fan's themselves or the control unit? The temp sensor is obviously working, and it doesn't seem to burn or leak coolant. 

 

Thanks for any insight! 

Carl

 

[Loren]

 

When they changed the radiator did they do a vacuum fill?

If not, then you likely have air trapped in the engine.

 

The fans can be tested with a Porsche specific diagnostic too (like Durametric, or Porsche PIWIS). Good shops one or more of those tools.