Porsche Enthusiasts Club Forum

On holiday I noticed I was losing about 1 litre of coolant every 150miles 'ish.
when I got back home I took the car to a garage and we had it up on the ramps and could see no evidence of any water leak, we drained a little of coolant and topped it up with antifreeze mix to correct level.
Checked engine oil, oil looks perfect very clean it's only done about 2000 miles since oil change, there is no gunge at all in the oil filler cap/hole
I drove it about 40 miles came back home checked coolant and it was at its correct level.

I did not drive the car for a week or so, checked coolant today before going out and had to put in 2 litres of coolant, could not see any coolant under the car, drove the car for 40 miles again, checked coolant when I got back and it has not lost any.
What are the places to look for a water leak, could the expansion tank cap be leaking and it's venting out there?
anybody had issues like this,
2000 996 Carrera4

Have you checked the rads at the front, sounds silly but pal of mine took his bumper off to fit rad grills and found full of water. One of the rads had rotted out with debris trapped between the air con and engine rad

Good tip, before I bought the car he said that they had fitted 2 new radiators at front, but it could still be leaking from a pipe there, I know we did not check at the front but i didn't see any water on drive at front or back but i will get it checked out

Steve , worth a look as my friends had no water drop but he had a fair amount come off the inside of the bumper once he released it from the car, must have been caught on a ledge

I have a similar problem on my 996, was given some advice that it might be rad cap. But at a recent free inspection at our local OPC they found a leak from the gearbox sump that is dripping onto one of the water hoses running from front to back and turned it porous. The assumption is that as the water pipe gets hot it leaks water and the heat from the pipe burns of the small tip leak.
Car is in OPC now so hopefully problems are solved
Hope this helps and good luck

Remember after the 40 mile run and expansion tank was a correct level yesterday, checked this morning, no sign of coolant in tank, going to garage and telling them of your suggestions to check:)

I'd suggest it's the expansion tank, invisible hairline cracks behind the tank open up under pressure and let steam out.

Happened to me in the middle of the Pyrenees, here's me fixing it:

Thanks Paul, nice pic!:))
Driven in the Pyrenees, not in the Porsche, but it will happen one day.. I will look at expansion tank too, it's on the ramp at garage, they have had a busy day and not had long to look at it, but first impressions they said they can see coolant red stains approx back of front drive shaft area, they will be removing underneath covers tomorrow to see if they can pinpoint the leak.
Don't know about everyone else? but up here in Newcastle upon Tyne area it's really starting to feel cold.

Found the leak.. looking from the front, left hand side in front of wheel, pipe was split but would not leak until you squeezed the pipe! could not get a new Porsche one quick, but garage said a VW pipe fitted perfectly..