Porsche Enthusiasts Club Forum

Following on from my header tank exploits - I started up the car today. I followed Clarks garage tips and put the heater to full hot and fan to full blast.
The water level in the header tank didnt move at all. I left the car idling for about 20 minutes and during this time the temperatur gauge stayed about level, i.e. at the first marker.

I then turned off the car and went away for a while. On my return the fluid in the header tank was at the minimum mark. I have topped up back half way between the min and max marks.

Is this ok?

How would i know if the system needed bleeding?

Assuming you already have bled it on refilling. Blowing into the header works for me. But yes it is normal for the level to drop itself all of a sudden when you think you have it bled. At least thats what mine does. Just top it up & keep an eye on it until it settles down. Then keep an eye on it anyway!

I found the bleed screw only so much use on the 944 and after a few runs it needed further topping up.

I give the rad hose a good squeeze too as this can sometimes release trapped air.

Rav

You will find the level will be a bit higher when hot than cold. I wouldnt worry if the temp gauge is OK and the level stays above the min. There could have been a little air in it that has been pushed out causing the level to drop.

Rich

Sounds normal to me.

Assuming most of the bleeding has taken place I have been led to believe that the 944 system will self bleed to a small degree, hence the cause of your level dropping.

One way I bled my system was to use a bike pump (albeit a swanky one) and an inner tube with the end tied up. Surprisingly, it bled the system much better than the gravity method (the car took 4 litres with the gravity method, but it took 8 with the pressuriser).

Thanks for the advice guys.
I have been using the car in preparation for the journey to Husbourne Crawley this weekend.
The temperature gauge seems fine with cars fans cutting in and out. Level hasnt dropped since topping it up and the strange gurrgling of water from behind the dash has now gone.
I am led to believe that this is air stuck in the heater matrix.

All is looking good for this weekend !

How do you do that then? Seal up one end of the inner tube and put the other end over the opening in the tank?

I think I have an old inner tube lying around somewhere so will have to try this when I get around to flushing mine.