Hi Guys, I am losing coolant about every 6 to 8 weeks or so, the dash warning lights up and about a litre of fluid is gone? I don't have any water in the oil or oil in the water and no overheating issues. The hoses appear OK. The car is a 520i 2.2 petrol 6 cylinder 2004 European model, covered 102000 miles.
I have read on other threads recommending that the water pump is changed at 100k miles . There is sometimes a wet patch behind the drivers front wheel,but the car is parked with a camber to the right, and I'm assuming it's the drain, it rains a lot here in England. I was wondering if the water pump gland is leaking or weeping that's why the loss is slow.
Anybody here had the same type of fault?
Any help gratefully received.

 

I believe you are correct about the drain, so that's probably not it.

Have you checked the expansion tank? It's one of many cooling items that tends to fail around 100k. Even if that isn't it, you should look to replace hoses, expansion tank, and water pump around now.

 

on my 550i, the temp sensor o-ring that is located by the return hose on bottom of radiator, was leaking enough to slowly lose coolant, but not enough to be noticed or leave a puddle.

 

If you are at 100K and have not yet done so, it's time for a complete cooling system overhaul. You likely have a leak somewhere. You should not be losing coolant at all, let alone one liter every two months.

 

Thanks guys, I will check the tank and O ring , and then get it to the Indi, for a pressure test and possible new pump and hoses, Time to treat Bertie to some new silicon hoses.

 

Check the expansion tank, and you might also try replacing the coolant cap. On the 6-cylinder cars there is a small hose that goes from the expansion tank across the radiator that can break and cause a small coolant leak.