Hey Everyone,
As the weather here on the East Coast starts to warm up, I know that I will run into the same problem that I faced last year. I have a 2000 996 Cab and when I am in stop and go traffic, or driving off of the highway, my temp gauge shows very high readings (above 180) and, eventually, the red light start blinking as if I am overheating. During highway driving, I don't have any issues. I know that people have posted this topic before and I have read about a couple of fixes (i.e. cleaning the radiators), but someone once mentioned changing the Coolant Cap to a new, redesigned one that Porsche introduced. Will this help? I am hesitant to rip the bumper off and clean the radiators myself, so I'm looking for easier fixes.

Any help would be great.

Thanks!

 

There could be many different things, first it could be just clogged radiator grill. Clean up should do the job. Second, the thermostat is about to go bad, it opens & closes erratically. Third, check to see any coolant leak or stain at the water pump. Fourth, the expansion tank & cap. See if the tank has any coolant leak, stain. Check the cap too. Also when was the last time you did the radiator flush. Some time bad coolant can rusted the inside of the radiator grill. A good flush done by professional is a must.

 

take off the bumper and clean, that takes 45 minutes at the most, get a new cap and do a complete flush while making sure that you bleed the system correctly, find a link for wiring your ac fans to constant or switched to control traffic temps and worst case, take it to an indy in your area...all of it combined may cost 4-500 in labor and is well worth the money.....tad bit cheaper than an engine and you don't dare drive it again with the light blinking.....ever!

 

what is normal operating temps for a 3.4L MY99?

 

Make sure you have enough coolant/water

 

I'd pony up some $ for a proper servicing to find the cause (if you're not inclined to DIY). A new engine is ~not~ cheap!

 

If your gauge does not move to the extreme right and the light is blinking, it does not indicate an overheating condition. Low coolant level will cause the light to blink as well a bad signal from the engine compartment fan or faulty coolant temperature sensor. How fast the light flashes can help diagnois the problem.

If the light flashes slowly, it indicates low coolant level or engine compartment temperature too high. If it flashes rapidly, it is the temperature sensor, and if it is a solid light, the temperature is too high.

Test your engine fan for proper operation and make sure your coolant level is correct, (more is better)

 

Great to know, thanks for posting-

 

Yes, thanks for posting.

I kinda thought that the temp bar needed to be far right. But there seems to be a lot of concerns on the forum about running mid zero on the 180 mark. This concerned me since I have been running between 8 and 0 mostly but slightly past zero when being very spirited (30 mins of ramp action and highspeed routes off of local highway the other day)

 

mine sits bone-solid between 8 and 0, never moves.

 

Your high coolant temperature is caused by various design flaws with the 996. The 2 biggest flaws include the restriction in the amount of air that can pass over the radiators at slow speeds and the fact that the radiator fan sensors turn on the fans too late and at too high of a temperature. Another contributing factor is the poor quaity of the water pump which causes it to wear quite quickly, thereby reducing the volume of coolant flow at low engine rpms. You'll identify this problem by increasing engine rpms to 1500 and watchiing the coolant temperature drop. The engine was designed to run between 190F - 200F in all conditions.

These temperatures can easily be maintained by doing my radiator fan mod which allows you to run the fans at high speed when needed. At slow speeds, there is not enough air flow to keep the coolant at the targeted temperature unless the fans are engaged.

It is common, but not good, that your coolant temperature to reach 215F+ in traffiic on warm days.