Engine running hot...
07-07-2011, 06:18 PM
#31
Rennlist Member
I check my fans in the summer. Turn the AC on and it fires up to low. I turn the fan mod switch and it kicks up to high.
The radiators were cleaned beginning of last summer and the fans cool the engine down quickly. 5,000 miles and one year later, it doesn't cool as fast and the temp is also a few degrees C higher on a hot day. Cleaning the radiators is very important from this observation...
The radiators were cleaned beginning of last summer and the fans cool the engine down quickly. 5,000 miles and one year later, it doesn't cool as fast and the temp is also a few degrees C higher on a hot day. Cleaning the radiators is very important from this observation...
07-07-2011, 06:46 PM
#32
Race Director
Porsche techs tell me they often find a car that comes in that has had front end work/repairs that involve the A/C condensor and radiator with misrouted wiring even to the point of finding the relay has been jammed in between some plastic panels. The relay runs hot so this is not good. It should be properly mounted to receive cool air and to avoid flopping about which can cause the wiring to fail from fatigue.
Now in my Boxster's case a relay was found bad and the front end while it had been worked on a long time ago (at the Wichita KS Porsche dealership service department) had everything routed properly the tech believed that the relay just reached the end of its life. BTW, the non-functioning radiator fan motor was on the passenger side (which was not the side the dealer worked on though) but in the USA it is the passenger side that is often subjected to heavier and more frequent water splashes.
In the case of the Turbo while the front end the passenger side had been worked on all the work was done at a Porsche dealer. Furthermore, I had the work inspected at another dealer by a senior tech there to confirm the work was done right -- I had the bumper cover removed and the work inspected very closely by this tech at the 2nd dealership -- the fan was not working because the radiator fan motor's shaft snapped. In snapping the hub/fan assembly banged into the back of the radiator. While this didn't hole the radiator it damaged it (bent some fins over) nonetheless and both the radiator and the fan/motor assembly were replaced under CPO warranty. The tech told me he had never seen a radiator fan/motor shaft snap before.
Oh, before the reason the Turbo's passenger fan was not working was determined I asked about the relay and water splash and the tech took the time to point out where the relay was located and it was located correctly (of course, for it was he that had inspected it before and pronounced the routing and in fact all the work done under the front bumper cover of the Turbo correct and 'factory') and in a quite protected area, nowhere near as exposed to the elements as the relay in the Boxster.
Sincerely,
Macster.
07-08-2011, 08:06 AM
#33
Three Wheelin'
I've been getting a ENGINE COMPARTMENT BLOWER FAN warning light in my 996 GT3 intermittently at the track, but when I pull into the pits, the engine compartment fan is blowing. Can this warning light be related to front radiator fans?
07-10-2011, 01:09 PM
#34
Rocky Mountain High
Rennlist Member
Rennlist Member
Thread Starter
The car is back now and in good working order. It has two new fans and two new fan relays. According to the tech, the fans were simply worn out. He said that both fans were inoperative when power was applied directly to them. He told me that this isn't as common as a bad relay, but in a car with over 100K on the clock, it's not unheard of.
07-10-2011, 05:00 PM
#35
Race Director
Their functionality is monitored so to speak by the coolant temp gage and the engine coolant warning light. That is if anything was wrong with the fans you'd know it from the coolant gage and if seriously wrong from the warning light.
(You should always before a track event check that both radiator fans are running before you head out and when you come in after a cooldown lap verify the fans are still working ok.)
The fan is running so the fan and its wiring circuitry (including the fuse in the fuse panel) appear to be ok.
I'm not sure -- I've never had any reason to dig into this area of any of my Porsches -- but my WAG is the problem is related to a temp sensor that is located in that general area. It is this sensor's output (fed to the DME) which is used to monitor engine compartment air temp and this sensor's reading is used to control the fan, to turn it on when teh temp gets too high and to turn the fan off when the air temp drops to an acceptable level.
The temp sensor may be loose or going bad.
The engine compartment fan plays a critical role in keeping engine compartment temperature down and the lower the heat the less heat damage the components in the engine compartment experience, so my advice would be to take the car to an expert and have this looked into and get to the bottom of the cause of the blinking light.
Sincerely,
Macster.
07-10-2011, 06:55 PM
#37
Race Director
What about setting the pin up on the bleed valve to bypass the thermostat?
There's been a bit of discussion here. This provides us with a cheaper (free) option compared to paying $$ to fit in a new thermostat.
There's been a bit of discussion here. This provides us with a cheaper (free) option compared to paying $$ to fit in a new thermostat.
The coolant's resistance to boiling is primarily derived from the pressure the cooling system builds when the cooling system gets hot, up to temperature hot.
If the cooling system can't hold pressure due to a water pump leaking or any other leak in the cooling system the leak should be found and fixed.
Opening some pressure bypass/relief valve on top of the coolant resevior tank simply creates an even larger pressure leak which under some operating conditions can allow localized overheating to occur with risk of serious engine troubles this brings with it.
Sincerely,
Macster.
