Loosing coolant..

Tue May 03, 2011 2:16 am

Well guys, past 2weeks the bimmer has been losing a bit of water. Mainly con fussed as I pressure tested it and it was fine..... Held pressure well, doesn't overheat, no mixing of water with oil..... Seriously confussed?! Help needed lool.. Thanks

Tue May 03, 2011 9:03 am

Water pumps can sometimes only leak when the engine is running.
IIRC, dried coolant fluoresces under ultra violet light, so a 'black' light in the dark may give some clues.

Fri May 13, 2011 9:03 pm

Mine did this for a while last winter. Every week I had to top up the expansion tank by about a cupful to bring it back up to the mark; it was a little rough in the morning for about the first mile, and there was a bit more steam from the exhaust than usual when cold.

No problems and no leaks so I carried on like this for a while ”“ until a hose split.

It turned out to be a head gasket leaking water into Cylinder 1. Another symptom was rock hard hoses when running.
New head gasket and 12,000 miles later I have a stable coolant and softer hoses.

Sat May 14, 2011 6:00 pm

Give your pipes a wiggle and a squeeze while its running. I had a tiny hole in one of my coolant pipes. It was a tiny little bit of spray and only when the engine moved. On tick over it was fine you wouldnt notice anything. The hole was near the jubilee clamp on mine. Worth a look...