Running hot in the winter

[cayenneturbo]

I have a 04' Turbo, cooling system replaced about 30K ago. Now that winter is upon us this may sound like an odd question. It was 40' (F) yesterday and I was waiting in the parking lot to drop off kids. When I looked down the car temp was at 220+ but not yet 240. The A/C was off and I had turned down fan/heater 10 min earlier since car was hot inside. I turned the A/C on and the temp went back to 180, if I turn A/C off the temp rises. This is while parked. I will try using the heat tonight when I pick up my wife, I dont know if the A/C fan kicks on for heat.

No codes on Durametric, otherwise the car runs fine and does not get hot in traffic. Then again I usually have the A/C on.

Any suggestions?

[orthotist]

Possible radiator fan

Possible clogged radiator vents

Possible aux. Fan issue

[cayenneturbo]

I just replaced the big radiator fan. With A/C on, the fan works. With A/C off the fan comes on at around 220ish range, low speed. When I shut the car off the fans do not stay on. Using Durametric there are no codes. It is winter so its cold out, so the car runs 180. Does anyone know at what temp or condition would cause the fan to kick in at high speed or what conditions to induce the fans to remain on after the car is off for that "after cooling" period.

Much Thx

[Loren]

From the Porsche Tech Book...

"The thermostat starts to open at 83ºC, lift is 9.8 mm at 98ºC, and it reaches its maximum opening at 105ºC. Coolant temperature is measured at the engine block inlet."

The thermostat is is not fully open until 105 C - or 221 F. So that sounds normal.

Also...

"A supplementary electrical run-on pump provides circulation in the coolant circuit even after the engine has been switched off. Depending on coolant temperature and the last driving cycle (map derived from fuel consumption) this pump is actuated by the DME control module through a relay."

So it would appear that the fans do not run with the engine off - but an electric pump does.

[cayenneturbo]

Good to go, just want to get resolved before Arizona summer. It started this summer, but only on highway at high speed. The temp would rise past 220 and hit around 240, but if I slowed down the temp would drop. I would run 180 if stuck in traffic in 110 degree heat, but run hot on hwy. I noticed that the loud airplane sound ( I guess fan at high speed) was no longer present after driving, I just did the pipes/water pump etc 10K ago.

[bigbuzuki]

The fans can and do run with engine off. I have heard mine on several occasions.

Here's why as explained in the Porsche Service Information Technik section 2 page 45.

Fan Run-On

To cool the engine compartment the fans are switched on with the ignition OFF, depending on coolant temperature and the last driving cycle (map on fuel con- sumption). The switch-on threshold is between 90 °C and 93 °C and running time is between 15 seconds and a maximum of 13 minutes. Once fan run-on is concluded, the fans will not start again with Engine OFF.

In the Cayenne Turbo, the electric coolant run-on pump, which provides cooling for the turbocharger (to prevent oil coking), is activated through this function. The run-on pump is located behind the left front wheel wheelhouse liner. In addition, this pump is activated on the Cayenne S and Cayenne Turbo by the air-conditioning control module to utilize residual engine heat.

Edited December 25, 2013 by bigbuzuki

[ekstroemtj]

In the Cayenne Turbo, the electric coolant run-on pump, which provides cooling for the turbocharger (to prevent oil coking), is activated through this function. The run-on pump is located behind the left front wheel wheelhouse liner. In addition, this pump is activated on the Cayenne S and Cayenne Turbo by the air-conditioning control module to utilize residual engine heat.

Bigbuzuki....

DO you have picture or part number for this pump?

Thank you

[bigbuzuki]

It is a 95557215002, 95557215003, 95557215005, 95557215006, 95557215007 depending on your VIN.

[ekstroemtj]

Thank you very much