[DutchPaul]

Hello good BMW gearheads. My 2016 550i with 110,000 miles has started leaking coolant onto the garage floor. I've been adding about 10 ounces every few weeks. Only to the reservoir near the powerstreering location, the front one does not loose coolant. Then did a "priming function" (car in accessory mode, heat all the way up, fan on low) yesterday after adding a similar amount. I could hear the coolant pump motor run but not a lot of air bubbles came up visibly in either reservoir. Drove the car (its crazy hot here in Phoenix), parked it in the garage, and it lost a significant amount of coolant overnight. Usually its a fee drops, this time there was a stream/puddle on the garage floor. Any ideas as the where this could be leaking from? It appears near the coolant reservoir near the drivers side front of engine bay. But not visibly from looking into the engine compartment, only from where the coolant hits the garage floor. When looking online for new coolant reservoirs, I only see the front one that supplies the turbos. Any advice will be great!

[NikMN]

Check coolant lines on top of the engine under the turbo inlets. They get cooked from the heat and usually start leaking first

[DutchPaul]

Thank you NikMN! I just got off the phone with an indi BMW repair shop. They explained that its the Y-pipe feed lines to the turbo. Quote is for $3949. Is the Y-pipe the same as what you are referencing?

[argento]

I just did this on my S63, it was behind the alternator. But made a mess down to the crankcase. I removed all the way down to and including the exhaust manifold to be able to clean it all up. I replaced everything I could that is susceptible to failure. What a mess. GL.

Oh, I did not replace the turno return aux water pump, which quickly failed after it was all put back together. Replace it and make aure it’s primed and properly bled. New inlet/return hoses no longer have bleed screws.

[Smytty]

Originally Posted by DutchPaul

Thank you NikMN! I just got off the phone with an indi BMW repair shop. They explained that its the Y-pipe feed lines to the turbo. Quote is for $3949. Is the Y-pipe the same as what you are referencing?

If it is indeed the Y Pipe I just did this repair when changing out my plugs and coils. Idk how good you are with a wrench but it damn sure ain’t worth 4K the fitting is like $7 on Amazon. Just have to remove air ducts and charge pipe on drivers side to be able to reach it. Used some hose clamps to clamp all 3 lines hoses were in good shape. Even if they are changing all the hose attached to that fitting that is a ridiculous amount of money for the repair. I changed mine preventatively before it leaked Y was actually in decent shape compared to some. Y gets changed to a T since the exact Y I don’t think has been sourced the T is a better orientation for the replacement.

[DutchPaul]

I'm picking it up Monday from the shop and will get after this repair next weekend. The shop did state that they would replace the entire hose assembly with a new Y fitting, so it would entail removing much more of what sits in this hot V. As well, they recommended replacing the feed lines to the oil return block (which is prone to failure) as it sits right there by the Y pipe fitting.
I'm leaning toward just replacing the existing y fitting with a brass T fitting and doing the same for the upper turbo colant supply lines as I see them corroding as well.

[argento]

Here's a stainless option, I think it's same size for N63...

https://www.usplastic.com/catalog/it...4bGEHmxX7HuELN




GL

[NikMN]

Originally Posted by DutchPaul

Thank you NikMN! I just got off the phone with an indi BMW repair shop. They explained that its the Y-pipe feed lines to the turbo. Quote is for $3949. Is the Y-pipe the same as what you are referencing?

Yes that's the one. I replaced it with a brass one for now. Going to replace all the coolant lines for a peace of mind

[zrile]

Originally Posted by DutchPaul

Thank you NikMN! I just got off the phone with an indi BMW repair shop. They explained that its the Y-pipe feed lines to the turbo. Quote is for $3949. Is the Y-pipe the same as what you are referencing?

4000$???

[kohsin]

Originally Posted by zrile

4000$???

$4000 seems high. It's going to be expensive, around $2000 . I had mine done during covid, with the inflation, who knows.
They have to remove the turbos and surrounding parts.

[zrile]

Even 2000$ is a menace.... jeez...

[StradaRedlands]

Originally Posted by DutchPaul

(its crazy hot here in Phoenix),

Noticed you were in PHX, so a quick shout out for Babbit Motor Werks. We had some problems with our 528i when visiting family there and the N Scottsdale shop was amazing! If you're calling around for estimates, give them a try!