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Reverse flushing the heater core?
Posted: Tue Jun 21, 2022 6:58 pm
by canada karl
Which hose is inlet and which is outlet?
Re: Reverse flushing the heater core?
Posted: Tue Jun 21, 2022 9:24 pm
by Mike W.
The opposite of what I thought. Hot should be on top, and cold or return on the bottom. Wrong. I'll spare you the long story, but it is,
Hot or in on the bottom.
Re: Reverse flushing the heater core?
Posted: Wed Jun 22, 2022 8:38 am
by canada karl
So to reverse flush the heater core I go thru the cold on the top,correct?
Re: Reverse flushing the heater core?
Posted: Wed Jun 22, 2022 11:38 am
by Mike W.
canada karl wrote: Wed Jun 22, 2022 8:38 am
So to reverse flush the heater core I go thru the cold on the top,correct?
Correct. But if you're really trying to flush it with a hose I'd go back and forth a few times, alternating between top and bottom.
Re: Reverse flushing the heater core?
Posted: Wed Jun 22, 2022 12:36 pm
by canada karl
Thanks Mike
Re: Reverse flushing the heater core?
Posted: Thu Jun 23, 2022 11:43 pm
by HB528i
I don’t think it really matters. We just had this discussion on the e9 Forum. On a CS water enters on top from manifold, on a CSi it enters on bottom, same heater. Some say it enters on top from back of head on a CS, it’s not going to make a difference.
Re: Reverse flushing the heater core?
Posted: Fri Jun 24, 2022 11:26 am
by Mike W.
HB528i wrote: Thu Jun 23, 2022 11:43 pm
I don’t think it really matters. We just had this discussion on the e9 Forum. On a CS water enters on top from manifold, on a CSi it enters on bottom, same heater. Some say it enters on top from back of head on a CS, it’s not going to make a difference.
I don't think E9s had a heater valve, I know E3s did not, and that is the difference. If connected wrong the heater valve can flutter and bypass coolant in an E12.
Re: Reverse flushing the heater core?
Posted: Fri Jun 24, 2022 1:05 pm
by HB528i
Thanks, I assumed no valve in the e12.
Re: Reverse flushing the heater core?
Posted: Sat Jun 25, 2022 11:42 am
by Mike W.
HB528i wrote: Fri Jun 24, 2022 1:05 pm
Thanks, I assumed no valve in the e12.
There is and replacing it has been described as the worst job on the car.
Re: Reverse flushing the heater core?
Posted: Mon Jun 27, 2022 8:16 am
by canada karl
Yah you need tiny fingers and a tiny wench!
Re: Reverse flushing the heater core?
Posted: Mon Jun 27, 2022 11:09 am
by Mike W.
canada karl wrote: Mon Jun 27, 2022 8:16 am
Yah you need tiny fingers and a tiny wench!
And to be a contortionist while laying on your back.
