[christiankirana]

So yesterday I had just did the Oil Filter Housing gasket replacement ( http://www.e90post.com/forums/showthread.php?t=791674 ). In one of the steps, I took out the engine block coolant hose to get better access in removing the OFHG bolts.



However, I'm now confused on where should I put the o-ring for the coolant hose. Is it suppose to be like on the first photo or second photo?



or



Another problem that I faced is when choosing to install the coolant like on the 1st photo, The o-ring seems to be too big and loose to stay on this sort of protruding shape of the connection (I'm not too sure what's the right word for it). Does that means my o-ring expands after being inside the engine for the last 8 yrs?

However, if I install the o-ring like on the 2nd photo, there will be a coolant leak as the 10mm flange bolt seems to only hold the top part of the coolant hose.

[Efthreeoh]

The o-ring is supposed to go in the groove as shown in the 1st photo.

[christiankirana]

but does the o-ring is suppose to be very loose or should it be perfect fit with the groove?

Originally Posted by Efthreeoh

The o-ring is supposed to go in the groove as shown in the 1st photo.

[Efthreeoh]

You have two choices re-use the o-ring (yours still looks good in the picture), or get a new one. I'm sure an auto parts store can match it up for you. The size is: 29x2.9 or BMW P/N 11537545278

[blackturbo]

Originally Posted by Efthreeoh

You have two choices re-use the o-ring (yours still looks good in the picture), or get a new one. I'm sure an auto parts store can match it up for you. The size is: 29x2.9 or BMW P/N 11537545278

I truly appreciate this post. I had a slow slow coolant leak and just could not figure out where it was coming from. I replaced my ofhg a year ago.

i then saw a tiny tiny leak coming out from that hose with the o ring. The o ring was crimped.
such a headache the last few months. Thank you very much for your post!