[sonofsun]

132,900 miles

Radiator vent line burst and leaked coolant with low coolant lamp when wife took it to work. Added like 0.4 gallons of coolant mix and drove the car on the highway back home while watching coolant temperature and it didn't exceed 104 deg C.

Purchased a replacement vent line, replaced the mickey mouse flange (which I bought over a year back) and the mickey mouse flange just snapped on the way out of the engine (lucky that it didn't get stuck inside). Also removed the serpentine belt to clean it off coolant. Followed the DIY to use a hose locking plier and crushed the old plastic flange out. Installed the Aluminum one from FCP Euro and at first tightening the new bolts didn't seat the flange flush.

Gave it a good push with two hands (applied silicone to everything prior to assembly) and it became flush. Torqued the bolts, installed the new vent line and vented the coolant (added a good 3/4 of a gallon). Added a tad bit more and started the engine and warmed it up. Then let it cool for 2 hours and checked coolant level and took it for spin. So far no surprises and coolant temperature remains between 96 and 99 deg C on the highway.

Thanks all for all the info and guidance.

[StradaRedlands]

Originally Posted by sonofsun

132,900 miles

Radiator vent line burst and leaked coolant with low coolant lamp when wife took it to work. Added like 0.4 gallons of coolant mix and drove the car on the highway back home while watching coolant temperature and it didn't exceed 104 deg C.

Purchased a replacement vent line, replaced the mickey mouse flange (which I bought over a year back) and the mickey mouse flange just snapped on the way out of the engine (lucky that it didn't get stuck inside). Also removed the serpentine belt to clean it off coolant. Followed the DIY to use a hose locking plier and crushed the old plastic flange out. Installed the Aluminum one from FCP Euro and at first tightening the new bolts didn't seat the flange flush.

Gave it a good push with two hands (applied silicone to everything prior to assembly) and it became flush. Torqued the bolts, installed the new vent line and vented the coolant (added a good 3/4 of a gallon). Added a tad bit more and started the engine and warmed it up. Then let it cool for 2 hours and checked coolant level and took it for spin. So far no surprises and coolant temperature remains between 96 and 99 deg C on the highway.

Thanks all for all the info and guidance.

This is the best and most rewarding standard maintenance you can do on an E9x! Glad you were able to get the overflow line off without breaking that little nub of the radiator hose... that one is my bane!

[lowrydr310]

I pre-emptively replaced the flange on my 325i a few years ago and I'm glad I did. When removing the old hose with plastic flange, the plastic disintegrated.

My 330i has a new radiator, thermostat, water pump, and all new hoses, including the one with the mickey mouse flange, that were all replaced in 2020. How much time do I have until the plastic starts to crumble? I'm all about preventative maintenance, but I also don't like unnecessarily replacing things.

[Serf27]

They always fall apart when they’re removed. Rarely do you see one fail on its own.
I’ve had an aluminum one sitting here..
I wouldn’t add silicone to anything. The o rings seal fine, most of the time.

[e91Owner]

Originally Posted by Serf27

They always fall apart when they’re removed. Rarely do you see one fail on its own.
I’ve had an aluminum one sitting here..
I wouldn’t add silicone to anything. The o rings seal fine, most of the time.

By silicone, I think he was referring to lubricant, not rtv. I had to do the same with the aluminum flange. It’s a tight fit, at least the rein was.

[Mike K]

After putting the new flange in the freezer for an hour, the two hammer trick worked for me. Threaded the bolts in by hand, and gave the new flange a few taps thusly...

[Serf27]

Originally Posted by e91Owner

By silicone, I think he was referring to lubricant, not rtv. I had to do the same with the aluminum flange. It’s a tight fit, at least the rein was.

Yea, some lubrication helps the o rings slide in and keep them from tearing.

[ZGator]

I had some trouble with the Rein fitting in as well, lubed with oil, pushed as hard as possible but was not working the bolts bound up with the gap below, I found the best way to is to get it even, start bolts with fingers and put them in bout halfway, and leave it for 5 or 10 minutes - then push with thumbs top and bottom and it did indeed finally pop in nice and flush - if you just try to force the bolts bad things might happen!

Fortunately for me I was doing the water pump/tstat and had removed this tstat hose - then I used a vice to break the old one out and also remove the thick factory clamp. Not sure how people get that clamp off or not break pieces down the pipe while attached. Just heads up to people to do this when if you are doing the tstat!!

[GnomeChild]

I went with the Dewhel kit like what Vehicluar DIY used as it seemed to be straightforward/no issues from his video, it was black, and didn't have an ugly clamp like the Rein kit (also $10 cheaper).

I used that money saved to buy an OEM 1" BMW clamp (07129952113) and a 5/16 brake line tube to upgrade the McDonald's straw while I'm in there (will be reusing the original ear-clamps)

None of my lines are busted (yet) but at 96k I am beginning to run on borrowed time, so might as well do them eventually

None of those are affiliate links btw

[Mikasa_e92]

So mu n54 had a alloy one already on when i got the car. Was fine for about 12 months but it became time to do the ofhg since i was fitting a mossleman stat also.
When refitting eveything i noticed a small leak from the flange. Instantly i knew it was the rubber seal gone. Got a new flange from ebay next day delivery and fitted that. Noticed the oring was flattened out, compared to the new one.
I guess i could of replaced just the oring but these alloy flanges cost like £6 delivered.
Moral of the story, anytime you remove a part with a old oring, likely youll need to replace the oring. (Same happened with that s pipe that goes from upper rad to the ofh. Removed old one (ages ago) and the oring expanded or something. Either way it wouldn't reseal.
Replaced that whole upper pipe with a new one, to find the oring between this pipe and the pipe that leads to the heater matrix had failed also. Nightmare.

[lowrydr310]

I'm doing some preventative maintenance on my 335i which includes a new oil filter housing gasket and aluminum mickey mouse flange. I ordered the Rein hose with aluminum flange already attached but I absolutely cannot figure out how to get the lower part of the old hose off of the thermostat. I can't get a socket or flat head on the hose clamp to remove it.

So I'm keeping the original 160K mile hose for now and just replacing the flange. I had to remove the old flange to get the oil filter housing bolt out, and when I pulled it it split. I just used vise grips to crush the band clamp and the plastic all came out in 3 big chunks. I cut the band clamp off the replacement part with a Dremel damaging a brand new hose, just to get the new aluminum flange. I had no problem reinstalling it, just put some fresh coolant on the oring and it slid right in.

[StradaRedlands]

Originally Posted by lowrydr310

I'm doing some preventative maintenance on my 335i which includes a new oil filter housing gasket and aluminum mickey mouse flange. I ordered the Rein hose with aluminum flange already attached but I absolutely cannot figure out how to get the lower part of the old hose off of the thermostat. I can't get a socket or flat head on the hose clamp to remove it.

So I'm keeping the original 160K mile hose for now and just replacing the flange. I had to remove the old flange to get the oil filter housing bolt out, and when I pulled it it split. I just used vise grips to crush the band clamp and the plastic all came out in 3 big chunks. I cut the band clamp off the replacement part with a Dremel damaging a brand new hose, just to get the new aluminum flange. I had no problem reinstalling it, just put some fresh coolant on the oring and it slid right in.

I don't know how a N52 and N54 differ, but my hose on an N52 was VERY easy to take off. I wonder if you went through the wheel liner you would have access to to the clamp screw? I guess it doesn't matter now, so will hopefully last till you need to do the water pump/T stat.

[lowrydr310]

Originally Posted by StradaRedlands

I don't know how a N52 and N54 differ, but my hose on an N52 was VERY easy to take off. I wonder if you went through the wheel liner you would have access to to the clamp screw? I guess it doesn't matter now, so will hopefully last till you need to do the water pump/T stat.

I replaced the whole hose on my N52 325i when I installed the new metal clamp and it was really easy.

On this N54, the hose clamp is aligned in such a way that there's zero clearance to get to the screw. I have the wheel liners out, fan removed, and intercooler removed so there's lots of access space but the subframe is in the way. The water pump has been replaced already (at least once) along with that U hose that goes from the water pump to the thermostat. Actually this hose from the thermostat to the cylinder head may have even been replaced once before.

[StradaRedlands]

Originally Posted by lowrydr310

I replaced the whole hose on my N52 325i when I installed the new metal clamp and it was really easy.

On this N54, the hose clamp is aligned in such a way that there's zero clearance to get to the screw. I have the wheel liners out, fan removed, and intercooler removed so there's lots of access space but the subframe is in the way. The water pump has been replaced already (at least once) along with that U hose that goes from the water pump to the thermostat. Actually this hose from the thermostat to the cylinder head may have even been replaced once before.

Sucks that it's so much harder/impossible to get at on the N54 :-/
One of those things where you just hope for the best!

[lowrydr310]

Originally Posted by StradaRedlands

Sucks that it's so much harder/impossible to get at on the N54 :-/
One of those things where you just hope for the best!

Good news is that hoses on the E9x are fairly robust, and failure is unlikely. That 260K mile 325i I used to have lived a hard life in the desert and still has a few original hoses.

[StradaRedlands]

Originally Posted by lowrydr310

Good news is that hoses on the E9x are fairly robust, and failure is unlikely. That 260K mile 325i I used to have lived a hard life in the desert and still has a few original hoses.

I noticed that as well! The O-rings need replacing and fittings are hard to get off without braking, but the actual hoses seem pretty good!

[850CSi]

Can someone help me out here… I’m changing to aluminum in conjunction with OFHG job.

Aside from the o-ring that comes installed on the new rein part, is there any sort of spacer or plastic part that’s supposed to stay in the head? Trying to make sense of what I got when I pulled my old flange out.

[StradaRedlands]

Originally Posted by 850CSi

Can someone help me out here… I’m changing to aluminum in conjunction with OFHG job.

Aside from the o-ring that comes installed on the new rein part, is there any sort of spacer or plastic part that’s supposed to stay in the head? Trying to make sense of what I got when I pulled my old flange out.

The original plastic flange often breaks and leaves the leading portion broken off and stuck in the head. It needs to be pulled out, hopefully in one piece. The new flange is all one piece.

[850CSi]

Originally Posted by StradaRedlands

The original plastic flange often breaks and leaves the leading portion broken off and stuck in the head. It needs to be pulled out, hopefully in one piece. The new flange is all one piece.

Thanks! Yeah I looked at it again and it’s the same diameter as the new flange. Must be a piece left behind.

[StradaRedlands]

Originally Posted by 850CSi

Thanks! Yeah I looked at it again and it’s the same diameter as the new flange. Must be a piece left behind.

Yeah, it cracks right at the transition from the flat external portion to the cylinder internal. That's why they have to be replaced! I've never had one crumble on me, but have read of others that did. So be extra careful taking it off the hose, as pieces can fall down into it. That would be bad.

[Mike K]

Yeah cram a rag or pinch off that hose to keep the plastic crumbles out.

[PaulForeman]

Originally Posted by e91Owner

Anyone with the rein flange have this problem? For the life of me, I can't get that thing to sit flush at the bottom and of course it leaks. Tightened the bolts to the point of stretching them and have tried several times to reattach it. Thought at first that I might not have bitten all of the pieces out, but I had. Ordering more bolts, but wondering if I just got a POS from rein.

Just had my Rein flange "fail" after a year and about 15k miles.

Took it out and found the o-ring to be compressed and very brittle. Replaced the o-ring and put it back together. This seemed to work for me for now. The aluminum part is fine, just a bad o-ring. Then I went to leave a review on the part on FCP Euro and found other reviews stating the same thing.

OEM Replacement O-Ring is available online or at the dealer for ~$2-5 each. 11-53-7-545-278

OE Supplier O-Ring

OR

BMW OEM O-Ring


Had the same symptoms as e91Owner.