Expert: Tony Fox - 3/12/2011

Question
QUESTION: I have a 1994 BMW convertible and my mechanic put in a new heater core and I was still having problems the floor on the drivers side in the back is saturated with antifreeze.  So he put in another heater core and the floor on the drivers side in the front now is saturated.  He says there is no leaks I want to bleed the system because there's lots of air when you unscrew the cap.  I don't know what to do,this mechanic is a jerk but I paid a lot of money and he's made it worse.  He tells me there's supposed to be air in the system.  Even I know that's not right.  There's a screw next to the cap on the radiator is that what you loosen to get the air out. Or is the screw on the thermostat casing.Can you explain where that is. Thank you for your help

ANSWER: Hello Linda, let me know what model you have so i will know what engine we are talking about.
Are there any overheating issues?
Are you loosing coolant still or is the floor wet from the repair?

Tony



---------- FOLLOW-UP ----------

QUESTION: Hi, It's a 325IC.  The car doesn't overheat He put in the heater core and the floor in the back was wet  The mechanic claimed to have put in a new heater core now the floor in the front is wet.The anti-freeze was going down a little bit every day.  Sometimes after the car has been sitting all night we check the anti-freeze it bubbles out of the radiator.  The mechanic says he put a pressure test on and there's no leaks.  He also says he checked the fire wall and its dry. I just got the car back so I have to wait and see if the anti-freeze still goes down.

Answer
No there shouldnt be any air in the system, Sounds like you have 12 valve m30 engine if there is a bleeder on the thermostat housing. With the engine cold or with no pressure in the cooling system open the bleeder on the thermostat housing, water should come out, if not remove the screw altogether and stick a needle or something in the hole to clear it out.Fill the radiator until water comes out of this hole.Start the engine and let water flow out for a few minutes, close it up and open the little bleeder next to the radiator till it lets water out.
You will know its bled properly when you see a stream of water flowing in the hole that you put the water i from the direction of the small bleeder.
You may be confusing pressure when you open the cap as apposed to air in the system.

Good Luck

Tony