losing water - BMW Forum

dudehog · 12-13-2009, 07:36 AM

i have noticed the level in my expansion tank (when cold) is slowly going down. there are no leaks from what i can see anywhere, no icky badness in the cap or oil, no damp patches inside the car from leaky pipes. the coolant has anti freeze in it so i've looked for crystal of that on the joints/pipes.
the level is going down about a line at a time (look at the tank and you'll know what i mean). i can't think of anything it could be. it doesn't overheat at all. i'm currently keeping an eye on it for the daily level.
any thoughts would be welcomed. john.

marti5 · 12-13-2009, 07:54 AM

Worth checking around the water pump area for any signs of a leak it will more than likely be a brown residue rather than coolant crystals due to a failing bearing in the pump.

dudehog · 12-13-2009, 08:17 AM

yeah. the coolant is new so thats why i was looking for pink crystals. it's got a replacement engine in it now. the other went pop. it's a new rad too. someone said about a leaky head gasket?

marti5 · 12-13-2009, 08:40 AM

If its a leaky head gasket it will get worse and you will have gunk (mayo) on the dipstick and under the oil cap,might be worth getting a coolant dye that shows up under UV, good stuff, helped me find a leak on mine which I would never had found in a hundred years, do a google search to find.

dudehog · 12-13-2009, 08:44 AM

cool. i'll have a look for that. yeah there's no mayo on the stick or under the cap.. i guess i gotta get a uv light too? how much was the dye?

marti5 · 12-13-2009, 09:10 AM

Feser One UV Acid Green coolant for use in your watercooled pc |Specialtech.co.uk

dudehog · 12-13-2009, 09:16 AM

sweet. that's uber cheap too. i'm guessing the uv lamps are available on ebay and such?

marti5 · 12-13-2009, 09:31 AM

I have this one .

http://cgi.ebay.co.uk/INVICTALUX-UV-...item334f82468d

but this ones good as it plugs in the ciggy lighter

http://cgi.ebay.co.uk/LED-WORK-LIGHT...item518edecda1

dudehog · 12-13-2009, 09:45 AM

hey. thanks for all your help. as soon as i find out the problem i'll let you know. thanks again.

CanyonCreekMT · 12-13-2009, 10:00 AM

Quote:

Originally Posted by dudehog

i have noticed the level in my expansion tank (when cold) is slowly going down. there are no leaks from what i can see anywhere, no icky badness in the cap or oil, no damp patches inside the car from leaky pipes. the coolant has anti freeze in it so i've looked for crystal of that on the joints/pipes.
the level is going down about a line at a time (look at the tank and you'll know what i mean). i can't think of anything it could be. it doesn't overheat at all. i'm currently keeping an eye on it for the daily level.
any thoughts would be welcomed. john.

Coolant expands when it is hot and contract when cold so I would think this is normal unless you are having to add coolant.

dudehog · 12-21-2009, 09:58 AM

dudes i found it!!! ultimate driving machine my ass!!! i thought i'd jet wash the engine bay to get rid of all the silt and grimness from the roads, aaaaaaaaaaaanyway, the next day i noticed the very base of the expansion tank was ever so slighty wet, literally just around the ring of it. pink!!! the colour of my coolant. i followed the path it could take and below it and to the right is a plastic recess with a hole. traces of pink. the coolant had been making it's way in there and dissapearing through the hole and onto what was beneath it and no trace. i've ordered a genuine o-ring seal from bmw to replace it (aftermarket rad) and i hope this solves the problem. will let you all know.

witeshark · 12-21-2009, 10:08 AM

Well I hope that sorts it.

vicfreg · 01-04-2010, 05:08 PM

Water pump.
You should be hearing more noise from the engine than usual.