Bad Engine compartment blower fan?

[TRIATHLETE]

1999 C2 Coupe 6-speed 39K miles

Last week, during a "spirited" commute, going 120mph out of 4th gear, the dreaded overtemp warning light started flashing and did not go out until I parked the car. The engine temp was just north of 180 degrees (same as it usually is), so I don't think I was overheating. The light has not come back on since.

The owners manual says this warning light indicates a fault with the blower fan. I've had the car for one year and have NEVER seen or heard the blower fan operate. This surprises me as I live in Florida and the temps get pretty hot in summer. Never gave it a thought until this scare.

Should I be concerned? Will dumping the fault code from OBD II tell me anything? I drive my car everyday and hate to bring it back to the dealer (typically sits for three days) for an intermittent problem. Please advise and thank you EVERYONE for the great technical support, DIY info and general good vibe on this site.

Paul

[1999Porsche911]

Check your coolant level.

[Loren]

Covers all Carrera, GT3, TT / GT2 and Boxster cars

Here is the long explanation from the service manual on the flashing coolant light.

"Four functions of the coolant warning light:

1. Engine coolant level too low -- light flashes slowly (0.5 Hz)

2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)

3. Engine coolant temperature too high -- light is lit; pointer on the right

4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right

Note: The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously."

[1999Porsche911]

I thought all owners of a 99 996 knew that this light with nomal engine temperature was due to low coolant. Didn't we all have to have our coolant tank replaced because of leakage?

Anyway...fill up the coolant tank with a 50/50 mix of antifreeze/water and you should be fine. After running it through the system at full operating temperature, you can bleed the system or simply remove the coolant tank cap overnight and everything will be fine. Don't forget to replace the cap before driving again.

For info: If you want to test the operation of the engine compartment fan, unplug the 2 wire connector from the engine compartment temp sensor located on Bank 2 just recessed on the top of the engine rightside between the intake ducts. The fan should immediately turn on. You can do this just with the ignition key on and engine not running.

Edited May 11, 2005 by 1999Porsche911

[djantlive]

I doubt it's your fan since the fan doesn't usually turn on while you are going 120mph with plenty of air going in. Fan is usually kicked on when you are in traffic and engine getting too hot.

Check coolant level and maybe your thermo stat for blockage/failure

[TRIATHLETE]

Covers all Carrera, GT3, TT / GT2 and Boxster cars

Here is the long explanation from the service manual on the flashing coolant light.

"Four functions of the coolant warning light:

1. Engine coolant level too low -- light flashes slowly (0.5 Hz)

2. Engine compartment temperature too high -- light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)

3. Engine coolant temperature too high -- light is lit; pointer on the right

4. Temperature sensor at water outlet faulty -- light flashes rapidly (1 Hz) ; pointer on the right

Note: The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously."

<{POST_SNAPBACK}>

Thanks for the info. Coolant is definitely not the problem - checked that already. I believe there are actually two warning lights in the gauge. The larger one where the needle would peg if the car was overheating and a smaller warning light right next to it. The far one was flashing pretty fast but the main warning light was not lit. The temp indicated by the gauge needle was in the safe range.

It looks like I better find a ride to work for a couple of days...good thing I still have a year left on my warranty! I don't look forward to explaining to the service manager that I don't need the $850 annual service because I did it myself. Thank you DIY section!

[1999Porsche911]

Have you worked on the engine lately? Could the coolant level sensor connection on the bottom of the tank come loose? You may also run the engine without the coolant tank cap on and let the fluid rise to the top as it heats up. This will help remove any air in the system. Then leave the cap off all night. Air in the system will also cause the light to flash.

[TRIATHLETE]

Have you worked on the engine lately?  Could the coolant level sensor connection on the bottom of the tank come loose?  You may also run the engine without the coolant tank cap on and let the fluid rise to the top as it heats up.  This will help remove any air in the system.  Then leave the cap off all night.  Air in the system will also cause the light to flash.

<{POST_SNAPBACK}>

Thanks 1999Porsche911. I haven't touched the engine but the case is solved! You just saved me a trip to the dealer! I just re-checked the coolant tank and guess what? The reservoir is EMPTY! Boy do I feel humbled... I did the annual (15,000 mi in my case) service last month and only had to add a few ounces of water to the coolant reservoir. That is all it lost in 12 months.

I must have cross threaded the cap when I put it back on because it was difficult to remove and looks as though coolant may have been escaping from there. I just put a pint of water in and still am not up to the MIN mark. Crap! Should I ONLY use the Porsche anti-freeze? Please advise. Thanks again!

[Loren]

A cracked tank is fairly common too.

[1999Porsche911]

Any brand name coolant is fine. Maybe get a premixed gallon botlle and put in the trunk until you are comfortable that you are no longer losing coolant. If you have never replaced the coolant in the car, I would put that on your list of thing to do. You should change it every few years to help prevent sludge from building up and clogging the radiators.

Glad it worked out for you.

Edited May 11, 2005 by 1999Porsche911

[umn]

...[

Should I ONLY use the Porsche anti-freeze?   Please advise.  Thanks again!

...

Hi,

There are different types of antifreeze, and some are not compatible with each other. In fact, they are so incompatible that they can turn into some gelatinous gunk.

You need to use Porsche antifreeze or one that is compatible with Porsche.

See also this thread:

Antifreeze thread

Cheers

Uwe

Edited May 12, 2005 by umn

[djantlive]

Yup use porsche antifreeze as it's lifetime. Add distilled water also to prevent mineral build up.

[TRIATHLETE]

Hi,

There are different types of antifreeze, and some are not compatible with each other. In fact, they are so incompatible that they can turn into some gelatinous gunk.

You need to use Porsche antifreeze or one that is compatible with Porsche.

Cheers

Uwe

<{POST_SNAPBACK}>

Thanks Uwe. I'll definitely pick up the Porsche anti-freeze today. Fortunately, the dealer is only two miles from my office.

[Izzy]

I just had the very similar issue with the temp light this morning. It was flashing after a fast acceleration run, when I stopped at the end of a highway ramp. The outside temp was around 65F, the temp needle between the 8 and the 0, normal conditions.

No coolant leaks, the tank is the latest model. Coolant level is just above min.

The fan check above:

"For info: If you want to test the operation of the engine compartment fan, unplug the 2 wire connector from the engine compartment temp sensor located on Bank 2 just recessed on the top of the engine rightside between the intake ducts. The fan should immediately turn on. You can do this just with the ignition key on and engine not running."

Did this check and the fan did not turn on at all. Is this a real check or not?

I plan on getting some coolant tomorrow from Porsche and fill to MAX line, but before I order a new fan if that is the culprit, wanted to know if anyone has tried the verification above, or any other tricks.

Thank you

Icy

[Phil47]

I an experiencing an intermittent probelm with the coolant / engine compartment blower warning light. This comes on for no apparent reason (slow flash) and will often re-set if I turn the ignition off and back on again. Collant level is fine and air is being drawn into the left hand side intake. Engine temp is seldom more than about 80. Any advice please. The car is currently in Southern Spain and would prefer not to use the Porsch dealers here.

Phil

[Loren]

http://www.renntech.org/forums/index.php?showtopic=5

A bad tank sensor is not too uncommon.

[Poisonapple]

Great information on the location of that sensor, Izzy. I had a similar problem with inexplicable temperature light flashing despite fans all working at both speeds, proper coolant level and temperature. My car is a '99 996 C2 Cab with 20k miles on its second engine/trans. After reading about the engine compartment temperature sensor location, closer inspection revealed that it had fallen down near the exhaust manifold. This was likely giving randomly high temperature readings, causing the gauge light to flash. Simply restoring the sensor to its proper location seems to have solved the problem.

:thankyou: :renntech:

Scott

[dr914jr]

I once had a problem with my fan running long after the car was shut down because the engine compartment temp. sensor had fallen out of its grommet.

[bmohr]

ok..i just had the same issue....driving and a flashing temp gauge...but the temp was fine. Now, i just did some repairs to my car and some coolant leaked out so I replaced with some watered down porsche coolant given to me by my indy..but it really did seem extra watered down..anyway, can someone show me where the engine compartment temp sensor is located? I'll start there and then work my way to seeing if I have air in my tank, and or if there is a low level of coolant or a "light" mixture. TIA

Bmohr

[goodee]

The grommet is part # 993-110-530-01-OEM (99311053001).  I ordered it from Pelicanparts, but you can find it elsewhere.

 

http://www.pelicanparts.com/More_Info/993-110-530-01-OEM&SuperCat=Y&SVSVSI=912.htm

[Schnell Gelb]

Don't forget to clean all the leaves and debris from the radiators. Bumper off !