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[Dave Plowman (News)]

From someone who has problems posting to this group, but who can read it
ok.

From: Fiacc Larkin
Subject: heater problem
Date: Sun, 04 Dec 2005 23:15

"I have a BMW 96 316i E36 M42. Ive been having serious overheating
problems. My cooling system is somehow accumulating air to the point that
the fan wont kick in (presumably because an air lock is blocking the fan
sensor) and once that happens it doesn't take long before it overheats.
The annoying thing is that if its bled and topped up with coolant she'll
run perfectly for another week or so until the same thing happens again. I
took it to the dealer who just bled the cooling system and said it
wouldn't happen again. needless to say three days later it did. Obviously
the air is getting in very slowly so its gonna be very hard to find,
right? where should I start looking?"

--
*If at first you don't succeed, avoid skydiving.*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

[Blake Dodson]

Always pressure test the cap first, then the cooling system. Of course
you would need the correct tools...

If the cap is rated at 1.034 Bar (15lbs.) then I would pump it to
1.172-1.241Bar (17-18lbs.) and then watch the guage for several
minutes. If it drops then you grab a light and look for escaping
coolant as they should be easy to spot now.

But this does not always reveal more serious issues; sometimes cracked
heads and leaking headgaskets wont show unless the engine is good and
hot. Remove the cap and warm the engine fully. Ideally you should drive
it but you could loose you coolant. Using "BLOCK CHECK" tool insert
into the cap opening and begin pumping; if there are any combustion
gases present the blue fluid will turn to yellow.

If you plan to become proficient in maintaining your autos I encourage
all to invest in these tools I have mentioned. Stant makes a nice
coolant system pressure tester. There are several adapters available
to service your fleet. Bloc Check is a Mr. Gasket product, but I linked
an alternative.

http://www.stant.com/index.cfm?location_id=183
http://store.autotoolexpress.com/colete.html

Best Regards,
DieInterim