1994 525i head gasket causing fluid leak?

[fclake]

After replacing rad,pump,tstat and cap and bleeding it many times, everything seemed fine. I then drove her 300+ miles and stopped and there was fluid coming through the rad cap. does this mean small leak in the head gasket allowing a tiny amount of hot air in? also there is a very VERY small leak in the tstat housing, the car never ran mast mid-way on the gauge. can air get in through the tstat housing? Also the heat DID blow hot air at some point although now it dosent, when I bled the system I had the heat on full, is this lack of heat related? Thanks everybody! this site has been a giant $$$ SAVER.

[ber55ber55]

Are you sure you bleed the system correctly? BMW are notorious for being hard to bleed. The radiator water level need to be higher then the T-housing. You should part uphill...start the car....turn heater on full...open the radiator and the t-housing bleed screw...and keep pouring water in constantly and do not let the water level in the radiator go below the t-housing level. (NOTE: car must be at working temp for this to work properly since the thermo needs to open) You MIGHT still have a little air in there. You know all the air is out when your filling the radiator and the t-housing bleed screw has a constant flow of water. Im sure you might already know this, but it took me trail and error to finally do it correctly. I almost bought thermogasket (very reputable product to seal cracked cylinder heads and bad head gaskets) but then bleed it correctly and tada. No more overheating, no more low water level, and no water anywhere. Try it.

[ber55ber55]

Oh....and when the bleed screw is flowing water....close it....top of the radiator and close it...JOB DONE...hope I helped =) GOOD LUCK

[fclake]

Oh....and when the bleed screw is flowing water....close it....top of the radiator and close it...JOB DONE...hope I helped =) GOOD LUCK


I havent done the park on a hill trick so thanks for that. this is a 94 525i the plastic thermo housing has no bleed valve. there is only one on the rad. I will try the hill trick thanx

[ber55ber55]

its easier with two people.....like one constantly filling the radiator while the other person is ready to close the bleed screw....or the radiator bleed screw. Im sorry about that haha...i have a 1990 that has a t-housing bleed screw...

[Blitzkrieg Bob]

just open the bleed screw on the rad, and fill'er up till it the bleed screw weeps.

Make sure the heater is on and run the car for awhile, recheck the coolant level, and you should be good after a couple checks.

If you're really having trouble you do the mouth to rad pressure bleed.
This is an old M20 trick...
Wipe clean the rad opening, fill wipe again, open the bleed screw...Now pucker up and blow into the rad until coolant flows from the screw and close.