Heating issue w/ M42...hoses wrong???

[MikeDE]

Yes I know, there is an M42 subforum but I was hoping for some more exposure here.

I believe these (2) issues are related:

I just installed my M42, new cooling-system everything, 2:1 distilled water/BMW Blue, bled out fine and have been driving it for the last 3 days.

First it takes a long time to warm up, about 10-12 minutes.

Second, I turn the heat on, and I get hot air for about 30 secs then it goes cold. I then have to wait about 7-8mins then i'll get another 30 secs of hot air then it goes cold.

I think I may have to hoses to the heater core swapped the wrong way. As they sit now, the hose from the head goes to the top nipple, and the water pipe hose is on the bottom, should I have switched them?? Am I causing more problems by having them swapped??

[MikeDE]

NVM, found it, they're swapped.

Move along, nothing to see here.

[dude8383]

the hose from the head should be going to the bottom and the hose from the water pipe/crack pipe should be going to the top.

[MikeDE]

crack pipe

hahahaha...mine's new so I hope it'll last a while.


yeah...I checked realoem to see if they had a diagram of the hoses going into the core, checked the numbers and I do indeed have them reversed.

I'll swap them later if my Wife doesn't get home too late.

[dude8383]

hehe. get-r-done ;)

[MikeDE]

I did...this morning at 5am before I went to work. Only took 10mins and I had heat afterwards.

[Gerta]

Ha! Glad I saw this!

[Simon S]

I’m gonna leave this here for others who search and find this thread.