[abnatelee]

Currently, I am having one of my coolant pipes leak a little bit and started spraying on to my engine. It’s enough leakage to catch my attention, but not enough to be stesssed out about it.

I am refilling about half a cup of 50/50 coolant every 3 days. I am assuming that outside temp plays a role in this since it’s been 90+ degrees here in NC. I haven’t had this problem in NJ though.

No issues with the radiator whatsoever though.

The part circled in BLUE is giving me problems.


Can anyone help me with:

- Parts numbers for the coolant pipes

[Joe-BMW33]

You have a 2018 that came from factory with rubber lines. These failed and BMW replaced with updated braided aluminum lines under warranty for most of us. Unfortunately, the warranty is not extended. Here is everything you need to do it right.

[abnatelee]

Originally Posted by Joe-BMW33

You have a 2018 that came from factory with rubber lines. These failed and BMW replaced with updated braided aluminum lines under warranty for most of us. Unfortunately, the warranty is not extended. Here is everything you need to do it right.

Thank you so much for your help!

[NGT2]

My advice is to get it addressed asap. There have been multiple points of coolant leaks on these engines. Its really the only widespread issue I’ve seen. The hoses, tanks, and caps have all been leak points.

My 2020 just had its second tank leak and this time it got in the injectors and is causing replacement of the injectors on the driver side.

[jcal65]

Also check the water pump for leaks. Mine developed a leak at around 11,000 miles and was replaced under warranty.

[G30M]

Originally Posted by Joe-BMW33

You have a 2018 that came from factory with rubber lines. These failed and BMW replaced with updated braided aluminum lines under warranty for most of us. Unfortunately, the warranty is not extended. Here is everything you need to do it right.

Do the LCI have the updated lines?

[adhrp]

Originally Posted by G30M

Do the LCI have the updated lines?

2020 onwards have the updated lines.

[Joe-BMW33]

Originally Posted by G30M

Do the LCI have the updated lines?

Yes

[NGT2]

Originally Posted by adhrp

2020 onwards have the updated lines.

Do you know if the part number for the tank is the same on both pre LCI and LCI?

Joe thinks he’s noticed a trend that the tank leaks are all TU3 cars.

[adhrp]

Originally Posted by NGT2

Do you know if the part number for the tank is the same on both pre LCI and LCI?

Joe thinks he’s noticed a trend that the tank leaks are all TU3 cars.

The leaks aren't from the updated lines. From what I have read, 2020 (TU3) onwards the coolant tank was moved to the rear closer to the heat from the turbos. Before that it was in the front, which kept it father away from the heat. So Joe's observation is correct. How BMW is going to solve this is anyone's guess.

[NGT2]

Originally Posted by adhrp

The leaks aren't from the updated lines. From what I have read, 2020 (TU3) onwards the coolant tank was moved to the rear closer to the heat from the turbos. Before that it was in the front, which keeps is father away from the heat. So Joe's observation is correct. How BMW is going to solve this is anyone's guess.

Right, I knew it wasn’t from the lines. I was just curious why the tank would fail on the TU3 and not the TU2. I forgot about them moving the tank. Which is also why the injectors are getting contaminated. They need to have a recall but honestly, what’s to recall if they aren’t going to change the part? M5 guys claim they’re new tanks are a new part number but my SA said the tank going in currently is the same part as the last one.

I don’t know how they will fix it. There is a metal billet tank available for the M5 but not the M550. If they eventually offer one for the M550 and I still have it, I will seriously consider making that investment.

I don’t want any prospective buyers to be scared off by my currently sour attitude, as I haven’t seen any others lose two tanks in a few months time. And I haven’t seen pictures or talked to the tech to know it’s the exact same kind of leak. I guess it could have been the cap?? But if it happens for a third time before my warrranty runs up in Feb, I may just move on instead of buying the Route 66 and keeping it another year. I’ll be pissed about the Dinan exhaust expense but I can’t have a car that has that kind of failure every few months.

Hopefully my parts come in tomorrow, I get my car back complete with new rear brakes and Dinan exhaust, and I have an issue free run for the rest of the year and beyond.

[adhrp]

Originally Posted by NGT2

Right, I knew it wasn’t from the lines. I was just curious why the tank would fail on the TU3 and not the TU2. I forgot about them moving the tank. Which is also why the injectors are getting contaminated. They need to have a recall but honestly, what’s to recall if they aren’t going to change the part? M5 guys claim they’re new tanks are a new part number but my SA said the tank going in currently is the same part as the last one.

I don’t know how they will fix it. There is a metal billet tank available for the M5 but not the M550. If they eventually offer one for the M550 and I still have it, I will seriously consider making that investment.

I don’t want any prospective buyers to be scared off by my currently sour attitude, as I haven’t seen any others lose two tanks in a few months time. And I haven’t seen pictures or talked to the tech to know it’s the exact same kind of leak. I guess it could have been the cap?? But if it happens for a third time before my warrranty runs up in Feb, I may just move on instead of buying the Route 66 and keeping it another year. I’ll be pissed about the Dinan exhaust expense but I can’t have a car that has that kind of failure every few months.

Hopefully my parts come in tomorrow, I get my car back complete with new rear brakes and Dinan exhaust, and I have an issue free run for the rest of the year and beyond.

I hear you. FWIW, two successive failures of the tank are quite unusual on the M550i, so perhaps it was a bad part or a one-off fluke. The coolant system is definitely a recurring weak point though. As you probably remember, I had a hose leak a few months after my coolant tank was replaced, and it happened outside of the factory warranty and cost me 1K because Route 66 doesn't cover hoses.

[Gautam]

Originally Posted by NGT2

Right, I knew it wasn’t from the lines. I was just curious why the tank would fail on the TU3 and not the TU2. I forgot about them moving the tank. Which is also why the injectors are getting contaminated. They need to have a recall but honestly, what’s to recall if they aren’t going to change the part? M5 guys claim they’re new tanks are a new part number but my SA said the tank going in currently is the same part as the last one.

I don’t know how they will fix it. There is a metal billet tank available for the M5 but not the M550. If they eventually offer one for the M550 and I still have it, I will seriously consider making that investment.

I don’t want any prospective buyers to be scared off by my currently sour attitude, as I haven’t seen any others lose two tanks in a few months time. And I haven’t seen pictures or talked to the tech to know it’s the exact same kind of leak. I guess it could have been the cap?? But if it happens for a third time before my warrranty runs up in Feb, I may just move on instead of buying the Route 66 and keeping it another year. I’ll be pissed about the Dinan exhaust expense but I can’t have a car that has that kind of failure every few months.

Hopefully my parts come in tomorrow, I get my car back complete with new rear brakes and Dinan exhaust, and I have an issue free run for the rest of the year and beyond.

I’d be pissed if I were you as well. That said, while this is among the top 3 failures I’ve seen on this board (other two being radiator flaps and flex disc), having two leaks in such quick succession is unusual and unfortunate. Somehow I’ve dodged the tu2 rubber lines leaking all the way to 58k miles on my nearly 7 year old car. (Though to make up for it I’ve had other failures early, leave me alone bmw gods)

Originally Posted by adhrp

I hear you. FWIW, two successive failures of the tank are quite unusual on the M550i, so perhaps it was a bad part or a one-off fluke. The coolant system is definitely a recurring weak point though. As you probably remember, I had a hose leak a few months after my coolant tank was replaced, and it happened outside of the factory warranty and cost me 1K because Route 66 doesn't cover hoses.

That’s a bummer…perhaps it’s more cost effective to replace the lines proactively.

[adhrp]

Originally Posted by Gautam

That’s a bummer…perhaps it’s more cost effective to replace the lines proactively.

The part was $100 and labor $900. I wanted to replace the other coolant hoses so that I don't have to pay labor all over again but my SA repeatedly dissuaded me from "wasting my money"...he said the tech that worked on my car is very thorough and he was confident the other hoses were perfectly fine. So far so good. It was refreshing to see a dealership stop me from giving them my money... unless it's a long game to charge me for labor again when another hose inevitably fails a few months down the line (the pessimist in me might wonder)

[NGT2]

Originally Posted by adhrp

I hear you. FWIW, two successive failures of the tank are quite unusual on the M550i, so perhaps it was a bad part or a one-off fluke. The coolant system is definitely a recurring weak point though. As you probably remember, I had a hose leak a few months after my coolant tank was replaced, and it happened outside of the factory warranty and cost me 1K because Route 66 doesn't cover hoses.

Gautam I know guys are right about the successive failures being unusual and I’m counting on that. I have seen one other example of it, but it was on the M5 forum.

I also need to confirm whether or not it’s the same leaking seam as the first one. Last time they sent me a video but this time I haven’t seen anything.

What do y’all think the chances are that the M5 and M550 use the same tank? I’ll look it up. But if they do, then it stands to reason the metal billet tank would fit in the M550.

[NGT2]

Not the same part number. Clearly the same issue but the aftermarket aluminum tank is for the M5 and M8. So I assume it wouldn’t fit our cars.

Its also $1,200…

[G30M]

Originally Posted by NGT2

Do you know if the part number for the tank is the same on both pre LCI and LCI?

Joe thinks he’s noticed a trend that the tank leaks are all TU3 cars.

the theory is the pressure is transferred to the tanks because of those impenetrable lines.

so just transferred to the next weakest link, the plastic 2-piece tanks.

mechanics have suggested to underfill the coolant to near minimum and you won't have the expansion tanks crack from pressure build up.

any ideas how i can remove coolant?

[G30M]

Originally Posted by NGT2

Gautam I know guys are right about the successive failures being unusual and I’m counting on that. I have seen one other example of it, but it was on the M5 forum.

I also need to confirm whether or not it’s the same leaking seam as the first one. Last time they sent me a video but this time I haven’t seen anything.

What do y’all think the chances are that the M5 and M550 use the same tank? I’ll look it up. But if they do, then it stands to reason the metal billet tank would fit in the M550.

the engine & coolant tank lego jigsaw puzzle looks different. but i don't know for sure that they're different. just looks different to me not comparing them side by side.

[Joe-BMW33]

Anyone have pictures of where this tank is on the TU2 and the TU3 or a link to a thread on it? I assume this is not the tank in question?

I am feeling optimistically fortunate that the coolant leaks in the TU2 are solved with the braided lines and the expansion tank failure and the subsequent take out of the injectors is minimal given the cooler location. Just curious what we are talking about here. Not this right?

[NGT2]

Originally Posted by Joe-BMW33

Anyone have pictures of where this tank is on the TU2 and the TU3 or a link to a thread on it? I assume this is not the tank in question?

I am feeling optimistically fortunate that the coolant leaks in the TU2 are solved with the braided lines and the expansion tank failure and the subsequent take out of the injectors is minimal given the cooler location. Just curious what we are talking about here. Not this right?

TU3 is back and right a little.

[Joe-BMW33]

Originally Posted by NGT2

TU3 is back and right a little.

Thanks, I'll take a look when I get home to see where it is on mine.

I need to buy a plane ticket to Memphis to come out and detail that engine bay for you!

[NGT2]

Originally Posted by Joe-BMW33

Thanks, I'll take a look when I get home to see where it is on mine.

I need to buy a plane ticket to Memphis to come out and detail that engine bay for you!

Haha. If I can get it back, that’s on my to do list for either myself or my detailer to do. Needs a good cleaning, in general.