Help, need some logic confirmation here

[tomfer]

Hi All.............Again!,
I am not sure where to turn with this one, sometimes the engine over-heats, sometimes it don't. I believe that i have traced it down to these symptoms. When the engine is running if I turn on the defroster and it is blowing hot air, the engine does not over-heat. Now in further attempts to figure this, if facing the engine, the top right hand corner of the radiator will get hot, the top and bottom of the left hand corner is cold. When the car doesn't over-heat, I have complete flow, both side are warm. Does this perhaps sound like the heater core is clogged. I just replaced the radiator at the tune of $245.00(US), do have access to a used heater core, however, does this sound like the culprit or am I in the wrong direction. Any ideas would be appreciated. Thanks! Tom

[KC Ron Carter]

If the system has an air bubble it will not flow coolant through the heater core, causing the cool air on defrost.

Also the heater valve is elecric and when it fails it can cause lots of different issues.

Later,

[jeffreyb4me]

a clogged heater core or closed heater valve WILL NOT cause overheating [ with the temp. wheel on 'cold' the heater valve is powered closed and no coolant flows through the core anyway ]......you've replaced the radiator but didn't mention the thermostat's condition which sounds suspect since when it 'overheats' the L/S of the rad. is cold.....if the fan clutch or the aux. fan were the problem, all of the rad. would be very hot....................jb.

[BMW_CHICK]

Originally Posted by tomfer

Hi All.............Again!,
I am not sure where to turn with this one, sometimes the engine over-heats, sometimes it don't. I believe that i have traced it down to these symptoms. When the engine is running if I turn on the defroster and it is blowing hot air, the engine does not over-heat. Now in further attempts to figure this, if facing the engine, the top right hand corner of the radiator will get hot, the top and bottom of the left hand corner is cold. When the car doesn't over-heat, I have complete flow, both side are warm. Does this perhaps sound like the heater core is clogged. I just replaced the radiator at the tune of $245.00(US), do have access to a used heater core, however, does this sound like the culprit or am I in the wrong direction. Any ideas would be appreciated. Thanks! Tom

Thermostat? Or valve? my 2 cents...which ain't even worth that..lol..

BMW_CHICK :Newbie:

[jeffreyb4me]

THERMOSTAT..... ?...that's my 'guess', but are you
[BMW_CHICK] asking a question or making a statement........maybe i wasn't too clear..........jb.

[BMW_CHICK]

Originally Posted by jeffreyb4me

THERMOSTAT..... ?...that's my 'guess', but are you
[BMW_CHICK] asking a question or making a statement........maybe i wasn't too clear..........jb.

JB, honestly, I hadn't read your posting when I posted. I was simply replying to the original post (tomfer). I know that when I had similiar problems (with another car, not BMW)...it was the Thermostat or some valve in the cooling system...I was just suggesting that he check that out....

BMW_CHICK <---for the confusion....

[tomfer]

Originally Posted by BMW_CHICK

Thermostat? Or valve? my 2 cents...which ain't even worth that..lol..

BMW_CHICK :Newbie:

Hey Thanks, I really hope it is as easy as this, I did just replace the thermostat with an aftermarket off brand stat from Advance Auto Parts, but that could be bad. I did think of that, but over-ruled it, because I couldn't phantom it would go bad in three weeks. I will pull that out and see, how the car reacts. I know te car will run like crap w/o a stat. But just for the test purpose it sounds easy enough. If you have had similiar experiences, please let me know. I have replaced everything except the heater core and heater valve. you can IM me at tom_ferretti on yahoo or tomferretti on AOL.
Thanks,
Tom