It’s not the pressure there causing the problem. It’s cheap shit seals that BMW uses. Most of the issues on this engine have been related to seal failure. Oil control o-rings, coolant o-rings. Whenever I’ve taken apart any failing o-ring it disintegrates in my hand. Check out the front seal from the coolant pipe

And here's the seal that's on the back of the engine that the pipe seals into. Not sure why the front one was like that. Perhaps some corrosion?

Are you sure that the seal that discintergrated is BMW OE? Haven’t seen that one before even for the old ones that I have replaced in the past.

I’m not sure.

I’d be very surprised if this wasn’t the OEM seal though. The pipe I took out was the one piece design. I highly doubt the timing cover was removed and the seal replaced - that repair would likely exceed the value of the vehicle.

Anyway I’ve put on roughly 1000 miles on the car. No leaks. Happy with the repair so far - now the whole cooling system is brand new pretty much except for that one at the back of the block inside the bell housing.

Shhhhhh... it'll hear you. ;)

I need to do my whole system... including the crossover pipe. No leaks currently but I have most of the parts here already and I prefer planned downtime to forced downtime.

Understood. What brand of coolant transfer pipe did you go with? Did you buy an extra set of seals? I read that many people had a great deal of trouble getting the seal that goes into the front of the timing cover to sit properly, tearing it and what not. So I ended up spending a few extra bucks to get the seal but I found that it was very easy to do! I just went slowly, taking my time (I spent 45 min on it almost) using a borescope camera and small mirror along with copious amounts of silicone grease and one of those trim removal tools to slowly coax the seal into the gap until it was so flush I could barely feel the transition with my finger.

AGA brand. I used a bimmerfix stint setup on a buddies X5 and it failed rather quickly. Like 2 or 3 months. I'm not sure how it could have been installation error as we took our time, and I know many have had great success, but it just didn't work for us. Maybe we should have let the gasket maker setup longer... we only gave it ~15 hours but it still feels like a band-aid fix to me.

You know, now that I am typing this... I wouldn't mind doing the timing cover seal as well so maybe an OEM pipe with updated seals would be just as durable as the AGA version? Decisions, decisions.

SlickGT1


What is the e30 cap bar?

1.4 bar.

Only issue I have noticed thus far, don’t overfill in the summer, and plan to add some water in the first sup 40 degree day in winter. Just always fill cold and to the minimum line.

The expansion of the coolant is pretty nuts. I’ve noticed this in my earlier cars, and it took a while to realize that our system will only blow off steam after 2 bars of pressure. This is crazy by any automotive standard. Google this. It’s like BMW made it to blow expansion tanks to bits. BMW has since stopped this bullshit I believe for the most part.

Anyway, if you fill your tank to the max on the summer, the cap will release the excess all over the expansion tank. You will be fine for the rest of the summer. First freezing day, you will get a low coolant error, you add a bit of coolant or water and you will be good to go for the rest of winter. Just never fill to the max mark, or you will be wiping off the expansion tank. Which won’t explode when you do overfill, so it’s fine with the 1.4 cap. I have not used the factory 2.0 bar cap in 6 years. My hoses have not exploded, expansion tank is 6 years old now, I have not overheated, or froze anything, no vanishing coolant, none of the bullshit I keep seeing in these threads.

I ended up using the uro pipe and kit.

It was well made with clear instructions and accompanying YouTube video. I don’t think doing it properly (provided you’ve got the tools) with an expanding style cooling pipe is too much more work compared with the “Stent” style repair. The job looked intimidating but really it’s not that difficult. I could do it in a day for sure. I ended up breaking off the crank case breather tubes but I had replacements on hand (the replacements have heat shielding).

It’s been 3 months/1000 miles - no issues yet.

I’d recommend this kit.