Antifreeze issues

[JimEE]

On a road trip, going up a sweet set of mountain switchbacks, my 2000 Boxster S, began to overheat and the red light on the temp gauge began blinking indicating low coolant level. I had no antifreeze with me. I thought, I'd coast down the other side, that might help cool it off. It didn't. So, as I got into town I stopped at the nearest gas station and picked up some antifreeze, Zerex. I added some straight, then added water. Filled it up to between the min/max level. Drove off, temp returned to normal. For about 5 minutes. Then it spiked to 250 and wouldn't come back down.

Called Porsche road service, which was very helpful, having to call a tow truck for a 175 mile pickup/delivery to the closest Porsche dealer - for free.

The dealer said that when you mix normal antifreeze like Zerex with factory Porsche antifreeze, it tends to coagulate, turns to kind of Jello, and so, won't flow or cool.

Too bad I was 2000 miles from home when it happened. End result was a coolant flush and oil change and the 2K road trip back home was without incident.

The manual says only use Porsche approved coolant, which is not readily available in my situation. So, if you run into this situation just add distilled water until you can get to the dealer.

Any other known workarounds?? Known brands that are Porsche approved? Are web links to such approved antifreezes reliable?

Why does it coagulate? What's going on?

Thanks, Jim

[niebyl2002]

Do you know why the coolant went low? What happend?

Thanks

[JimEE]

No, I don't know why. I checked it at the start of the trip and it was at an appropriate level. The only thing the dealer who flushed out the system (not my home dealer), said, was that the radiator cap was somewhat cross threaded. But, I've never seen any leakage. Not under the car, no moisture around the cap in the rear trunk, no odors, or any other indicators of coolant leakage (wet carpet, etc).

The car had 17K on it when I bought it, I had put about 5K of mostly city driving, rarely going over 40mph between May and now. On the trip, I had put 2K miles on it at 70-80mph - sometimes faster.

Thanks, Jim

[Baconaire]

To lose that much coolant you must have problem real problem. Look for condsation on the trunk hood. That will be a sign of a lose cap.

I just replaced a smashed radiator. Drained the system and used Prestone and water. So far so good. It took about a week of driving, checking the overflow(in the trunk), and topping off to get it up to level. So far so good. The label on Prestone say it will work with ANY car. Others here have said they used it with no probs.

The red light just means the coolant level is low. It could be just a spash low and blink. The temp guage is the one to watch. If that goes into the red zone, don't drive. In emegency you can turn on the heat to try to flow some hottness away from the engine. But if you run hot you run the risk of killing the engine.