BMW: Bmw 535i (e34) losing too much coolant

Hello, I own a bmw e34 535i 1989 model, automatic with 201,000 kms. Recently
it has been losing a lot of coolant, however I have no idea where it is
going. There are absolutely no coolant leaks from the car (piping or the
radiator etc), the car drives fine, ie no overheating and still smooth to
drive. The engine was pressure tested (by Canterbury BMW, Sylvania, NSW,
Australia) for leaks at a recent service and nothing wrong was found.
Nothing wrong was found with the cooling system at all at the service from
BMW (http://www.sylvania.bmw.com.au/). Radiator hoses where replaced when
the 200,000 service was given. The kind of coolant loss I am talking about
approximately 500ml for 100 km worth of driving. When I have finished
driving the car after a trip, I cannot hear any unusual noises (ie boiling
or hissing of steam) from the car when the engine has been turned off after
a drive. Everything about the car seems fine, except for the coolant loss.

When filling up the car I predominantly (60% of the time) put in water, and
the rest of the time mix water with coolant (which is non-BMW). Is this
practice okay and what can I look for / and or tell the BMW dealer to look
for such a problem. I want to get it fixed now to avoid paying more for my
engine overheating in the future.


Regards

Kristian Ford

More likely a leaking heater core.
Turn off all of your heat, and set everything to cold.
NEVER turn on the heater or touch the controls.
Drive the same amount of miles you normally do (after filling up the
coolant) and see if you have lost any coolant.

If you use the heater at all, it will flow coolant through your heater
core and leak out. If you do not use trhe heater, you can determine if
it is the heater core or a leaking head gasket.

Usually a leaking head gasket will also cause over temp problems as
well.


In article <3f55fe16@news1>, com.au says...