dpastramas

Hi

I have a 996 4Cabrio (2002 model) and the following occured during this weekend.

I was up on the mountains for skiing. The weather was very heavy, very cold temperatures ( -15 Celsius, 5 Farhenheit). I didnt start the car all day, and in the evening we took the car to go out to the next village. The way up was quite steep with a lot of hair pins, and at a some point half-way, i got an indication/warning to check coolant level (even got the temperature light blinking, but the temperature didt rise)

I checked the coolant level when i arrived and it was indeed way below the min level.

The next day i added 2litres - 0.5 gallon of distilled water and 0.5 litre/0.1 gallon of coolant. The coolant level rised to the half point between min and max. I let the car run for 5mins and checked for leakage, but nothing spotted.

However the day after, i checked again after driving a bit, the coolant level again had dropped below the min level, but i didnt get any indication/warning. I drove back home for 1.5hours in heavy traffic, and no issues with water temperature.

Has this happend to anyone else? Could it be that the coolant contracts in very cold weather?

Thanks in advance for your help guys!

Pac996

Could be the pressure your system releases into the over flow has reduced. The coolant needs pressure on the fluid or the water boils easy which causes more water to go into the over flow system of things. So I'd imagine that would be a good thing to check on.

I'm not sure what the specifics of the porsche advised special porsche coolant they sell is but before going that route I'd make sure the system gets a new presure relief part.

Oh jah it appears there are some drain points on a tank for radiator fluid below where the battery is. Possibly this area could be leaking and not apear to be related to the radiators and overflow. I've wondered if there is a chance the fluids were frozen in some areas so flow wasn't happening but if your antifreeze was up to covering the temperature range I'd think you had a good flow and not restricting your radiators which would cause over heating and loos of coolant due to it blowing overboard in the overflow tank.

Barn996

Coolant tanks are known to crack and leak water/coolant and can be difficult to detect. Another item that fails is the coolant tank cap. Try a new cap 1st, it solved my problem when I bought my Porsche 3 yers ago. GL

Dave!

With a cracked tank the coolant tends to leak during cooldown when you're not around (at least that's what mine did). Park the car hot over dry pavement then come back out in 5 minutes. Look at the ground under the left tail-pipe and the tail-pipe itself, if the tank is leaking you'll see signs then (stains in the pavement, "water" spots on the tail-pipe).

Any time you have coolant disappearing though you need to check the oil for contamination. Look at the dipstick, if it looks milky your engine has a problem with intermix--you probably would have seen hints of oil in the coolant already and it is much less likely than a cracked tank but it's something you need to check just in case.

dpastramas

Thanks for your responses guys. Eventually i took the car to the "hospital". A seal in the cooling system failed and they had to change it and a pipe. No major deal.

It was however interesting that even with the leak, the engine didnt heat up. i was able to drive the car 100 miles with a leaking cooling system.

Pac996

Yah its better cooling running lines to the front but man are there ever a lot of extra connections to add to possible fault areas.