MakkyJ
01-13-2010, 05:39 PM
Hello,
I have recently rebuilt the top end of my 1990 525i (m20b25) as the old head cracked and was leaking oil into the radiator. The engine is running smooth after the rebuild (pressure tested head replacement and new gaskets all around) but I am concerned about the oil remnants in the cooling system and as this system is relatively difficult to bleed, I was curious as to what methods people have used to flush and clean out the cooling system. I cleaned all of the pipes, heater core, block, and the radiator when disassembled but of course I couldn't
I have flushed if a few times using cascade dishwasher soap (found on this forum as a suggestion) but cannot get all of the oil out (hopefully it is not still leaking). I was thinking that this is mostly due to the design of the cooling system as well as the fact that I have to let it cool prior to dumping the radiator.
I thought it might be a good idea to remove the thermostat and then reassemble and flush the engine half a dozen times without letting it get too warm as this would allow a more free circulation of the coolant. I am worried that this might mess up the heater core so I am leary to try.
I am only using water and dishwasher soap right now and If you have any suggestions, they would be most welcome.
Thanks,
John
P.S. should the dual climate control allow heat if either of the dials are set to heat while the other is set to cold. As it is, if the drivers side control is set to cold, the passenger doesn't blow heat at all, but if the drivers side is open to heat, then the passenger side blows heat. It is almost as if the passenger side doesn't respond and is dependent upon the drivers side controls.
I have recently rebuilt the top end of my 1990 525i (m20b25) as the old head cracked and was leaking oil into the radiator. The engine is running smooth after the rebuild (pressure tested head replacement and new gaskets all around) but I am concerned about the oil remnants in the cooling system and as this system is relatively difficult to bleed, I was curious as to what methods people have used to flush and clean out the cooling system. I cleaned all of the pipes, heater core, block, and the radiator when disassembled but of course I couldn't
I have flushed if a few times using cascade dishwasher soap (found on this forum as a suggestion) but cannot get all of the oil out (hopefully it is not still leaking). I was thinking that this is mostly due to the design of the cooling system as well as the fact that I have to let it cool prior to dumping the radiator.
I thought it might be a good idea to remove the thermostat and then reassemble and flush the engine half a dozen times without letting it get too warm as this would allow a more free circulation of the coolant. I am worried that this might mess up the heater core so I am leary to try.
I am only using water and dishwasher soap right now and If you have any suggestions, they would be most welcome.
Thanks,
John
P.S. should the dual climate control allow heat if either of the dials are set to heat while the other is set to cold. As it is, if the drivers side control is set to cold, the passenger doesn't blow heat at all, but if the drivers side is open to heat, then the passenger side blows heat. It is almost as if the passenger side doesn't respond and is dependent upon the drivers side controls.