[ProjektAutoScott]

This is a 2019 M850i. The components in question are shared with the G30 M550i, F90 M5, M8, and the newer X5, X6, and X7 N63 models. This is why I am posting in the more popular G30 forum.

The owner brought the car in for unrelated service. Immediately, I noticed a strong raw fuel odor from the front end of the car in the shop.

In the past, BMW has recalled a number of 2019 N63TU3 cars for leaking high pressure fuel pumps related to incorrect install. I assumed that's where the leak could be.

Strange and more concerning than that, the leak is coming from the non-serviceable junction between the high pressure fuel rail and high pressure injector line for cylinder 1. The leak was not visible without peeling back the factory foam insulation, which was soaked in raw fuel.

See the video for the leak, with the foam pushed back out of the way.

Possibly something to keep an eye on with these newer N63 and S63 powered cars. This M850i has about 30,000 miles on it. Clear ownership and service history. Nothing would indicate this fuel rail has ever been tampered with since production, nor have any of the high pressure fuel components been removed or reinstalled.

Bone stock car. Scary leak considering the fuel soaked insulation napalm, the proximity to heat, and the high voltage ignition/injection components.

https://youtube.com/shorts/c2qjJzeJd...tK18ACKNddM1lz

[adhrp]

Holy cow that's a major leak! First time I am hearing about this. Just a minor correction though - the 2019s are TU2. MY20+ are TU3. Has this been seen in the TU2 or TU3?

[ProjektAutoScott]

Originally Posted by adhrp

Holy cow that's a major leak! First time I am hearing about this. Just a minor correction though - the 2019s are TU2. MY20+ are TU3. Has this been seen in the TU2 or TU3?

I haven't seen much about this anywhere. Could just be a defect with this one.

You are correct for the G30 M550i models. TU2 until '20 in that case. However, this is a TU3 aka N63B44T3 in a '19 G14. There are no N63TU2 M850i models. I see a lot of confusion about that online. Outside of factory literature, the easiest way to tell if you have a TU2 vs a TU3 car is the big balancing/bypass tube between the two intercoolers on top of the engine, and no MAF sensors.

Regardless, part number for the rail is the same if you want to check applications: 13537852402

[adhrp]

Originally Posted by ProjektAutoScott

I haven't seen much about this anywhere. Could just be a defect with this one.

You are correct for the G30 M550i models. TU2 until '20 in that case. However, this is a TU3 aka N63B44T3 in a '19 G14. There are no N63TU2 M850i models. I see a lot of confusion about that online. Outside of factory literature, the easiest way to tell if you have a TU2 vs a TU3 car is the big balancing/bypass tube between the two intercoolers on top of the engine, and no MAF sensors.

Regardless, part number for the rail is the same if you want to check applications: 13537852402

Got it, thanks for clarifying. Hope this is a one-off! Can you elaborate on 'non-serviceable junction'? What's the solution then to this issue?

[ProjektAutoScott]

Sure. On many BMW models you will find a removable high pressure fuel line between the main high pressure fuel rail and each individual fuel injector. With threaded fittings on both ends, those lines can be serviced or replaced easily.

In this case, the fuel rail and injector lines are all one piece. You can see in the video that this leak is coming from a pinhole in a brazed or welded junction on the rail that cannot reasonably be serviced or repaired.

The solution is to replace the entire fuel rail for cylinders 1-4. $600 MSRP. After labor and markup, I'd imagine this would be $1,500+ at the dealership.

[ezaircon4jc]

Just slap some JB Weld on it and call it good

[Neusser]

Originally Posted by ProjektAutoScott

Sure. On many BMW models you will find a removable high pressure fuel line between the main high pressure fuel rail and each individual fuel injector. With threaded fittings on both ends, those lines can be serviced or replaced easily.

In this case, the fuel rail and injector lines are all one piece. You can see in the video that this leak is coming from a pinhole in a brazed or welded junction on the rail that cannot reasonably be serviced or repaired.

The solution is to replace the entire fuel rail for cylinders 1-4. $600 MSRP. After labor and markup, I'd imagine this would be $1,500+ at the dealership.

Not good. How many miles?

Over here, my local BMW shop (indy performance/race shop) strongly advised against getting these engines in any form. IDK what it is with BMW and V8s.

[ProjektAutoScott]

Originally Posted by Neusser

Not good. How many miles?

Over here, my local BMW shop (indy performance/race shop) strongly advised against getting these engines in any form. IDK what it is with BMW and V8s.

Approximately 30,000.

Yeah, I get that take. The V8s certainly aren't for everyone.

Some in the industry will develop strong negative feelings for any engine or car that ever gave them a hard time. My negative feelings are associated more with owners who don't understand or care for their cars.

In my experience a V8 beyond the first gen N63/S63 is totally manageable. I personally wouldn't hesitate to own a well maintained N63TU or newer V8. The V8s certainly come with more to care for, but that is the nature of additional cylinders and an extra engine bank.

For example, this fuel leak doesn't necessarily have to do with a V8 or I4/I6. Rather, the manufacturer who is producing these fuel rails for BMW. Likely Bosch. This type of fuel rail construction is very common across countless makes and models of direct injection engines.

Above all, I am just hoping this fuel leak is an isolated incident.

PSA: If you ever smell raw fuel while driving any modern car, shut it down immediately. With modern closed EVAP and emission control systems, a raw fuel smell is a failure somewhere and you are possibly at risk of fire. When I brought it up, this customer thought nothing was unusual about the intense fumes. Maybe cars just smell like gas, as if the M850i were a car from the 70s with a vented fuel tank and a carburetor.

[Joe-BMW33]

Originally Posted by ProjektAutoScott

Approximately 30,000.

Yeah, I get that take. The V8s certainly aren't for everyone.

Some in the industry will develop strong negative feelings for any engine or car that ever gave them a hard time. My negative feelings are associated more with owners who don't understand or care for their cars.

In my experience a V8 beyond the first gen N63/S63 is totally manageable. I personally wouldn't hesitate to own a well maintained N63TU or newer V8. The V8s certainly come with more to care for, but that is the nature of additional cylinders and an extra engine bank.

For example, this fuel leak doesn't necessarily have to do with a V8 or I4/I6. Rather, the manufacturer who is producing these fuel rails for BMW. Likely Bosch. This type of fuel rail construction is very common across countless makes and models of direct injection engines.

Above all, I am just hoping this fuel leak is an isolated incident.

PSA: If you ever smell raw fuel while driving any modern car, shut it down immediately. With modern closed EVAP and emission control systems, a raw fuel smell is a failure somewhere and you are possibly at risk of fire. When I brought it up, this customer thought nothing was unusual about the intense fumes. Maybe cars just smell like gas, as if the M850i were a car from the 70s with a vented fuel tank and a carburetor.

Most negative comments about the "BMW V8" are broad swipe ignorant statements (some jealousy too) and the people who make them apply it to all BMW V8's as a general rule of thumb, including mechanics. The TU2/3 and just as reliable as the B58.

Looks like you have an isolated issue here. I hope you get it repaired for a reasonable cost.

[Neusser]

Originally Posted by ProjektAutoScott

Approximately 30,000.

Yeah, I get that take. The V8s certainly aren't for everyone.

Some in the industry will develop strong negative feelings for any engine or car that ever gave them a hard time. My negative feelings are associated more with owners who don't understand or care for their cars.

In my experience a V8 beyond the first gen N63/S63 is totally manageable. I personally wouldn't hesitate to own a well maintained N63TU or newer V8. The V8s certainly come with more to care for, but that is the nature of additional cylinders and an extra engine bank.

For example, this fuel leak doesn't necessarily have to do with a V8 or I4/I6. Rather, the manufacturer who is producing these fuel rails for BMW. Likely Bosch. This type of fuel rail construction is very common across countless makes and models of direct injection engines.

Above all, I am just hoping this fuel leak is an isolated incident.

PSA: If you ever smell raw fuel while driving any modern car, shut it down immediately. With modern closed EVAP and emission control systems, a raw fuel smell is a failure somewhere and you are possibly at risk of fire. When I brought it up, this customer thought nothing was unusual about the intense fumes. Maybe cars just smell like gas, as if the M850i were a car from the 70s with a vented fuel tank and a carburetor.

Yes, I stopped with V8s after my S4. Was one of my least reliable cars, and I just don't like the nose-heavy dynamics.

My local shop guy swears by I6ers and has built several E46 M3s as 'Ring tools, so perhaps he is even more biased than I am.

[2022M550i]

Thanks for the heads up. It’s a good opportunity for an insurance job.

[2022M550i]

Originally Posted by Joe-BMW33

Most negative comments about the "BMW V8" are broad swipe ignorant statements (some jealousy too) and the people who make them apply it to all BMW V8's as a general rule of thumb, including mechanics. The TU2/3 and just as reliable as the B58.

Looks like you have an isolated issue here. I hope you get it repaired for a reasonable cost.

Yep and I remember starting a thread To document issues with our cars Hoping to expose some of the “horror“ stories. Nothing exposed… at least nothing happened with people who belong to this forum.

Now that I have said this, my car will catch fire tomorrow

[HerkHealer]

Originally Posted by ProjektAutoScott

Sure. On many BMW models you will find a removable high pressure fuel line between the main high pressure fuel rail and each individual fuel injector. With threaded fittings on both ends, those lines can be serviced or replaced easily.

In this case, the fuel rail and injector lines are all one piece. You can see in the video that this leak is coming from a pinhole in a brazed or welded junction on the rail that cannot reasonably be serviced or repaired.

The solution is to replace the entire fuel rail for cylinders 1-4. $600 MSRP. After labor and markup, I'd imagine this would be $1,500+ at the dealership.

Curious if this customer had catless downpipes?
From videos I've seen, you literally have to take half the engine apart to install them.

[2022M550i]

Originally Posted by HerkHealer

Curious if this customer had catless downpipes?
From videos I've seen, you literally have to take half the engine apart to install them.

When I see something like this, i always think of some kind of destructive mechanical Resonance coupled with poor construction/weld.

Resonance occurs when a forcing function excites the machine's natural frequency, causing an excess in vibration.

[HerkHealer]

Originally Posted by 2022M550i

When I see something like this, i always think of some kind of destructive mechanical Resonance coupled with poor construction/weld.

Resonance occurs when a forcing function excites the machine's natural frequency, causing an excess in vibration.

Could be, but if it were an engineering problem, i'd think we would see lots of this. Like our coolant loss. This is the first time I've heard about the fuel rail failing. Which is why I mentioned an upgrade/or service requiring its removal.
It does not take much to crack a weld if you're a moron.

[2022M550i]

Originally Posted by HerkHealer

Could be, but if it were an engineering problem, i'd think we would see lots of this. Like our coolant loss. This is the first time I've heard about the fuel rail failing. Which is why I mentioned an upgrade/or service requiring its removal.
It does not take much to crack a weld if you're a moron.

I think it’s a combination of Vibration And a poorly welded piece that led to Failure.

It could just be a one off. I can see a recall if they can trace back A large batch of contaminated welding wire or something that led to a poorly welded piece.

[ProjektAutoScott]

Originally Posted by HerkHealer

Curious if this customer had catless downpipes?
From videos I've seen, you literally have to take half the engine apart to install them.

as mentioned above, the car is bone stock. No modifications. I know this customer well, and I've know the car equally. There is no indication or service record that would indicate these lines have ever been touched since factory new.

You certainly don't need to mess with the fuel system to install downpipes, regardless.

But yeah, I agree that strain on those lines could cause someone a problem. It seems like this is a weld/braze defect though, as 2022M550i mentions.

[HerkHealer]

Originally Posted by ProjektAutoScott

as mentioned above, the car is bone stock. No modifications. I know this customer well, and I've know the car equally. There is no indication or service record that would indicate these lines have ever been touched since factory new.

You certainly don't need to mess with the fuel system to install downpipes, regardless.

But yeah, I agree that strain on those lines could cause someone a problem. It seems like this is a weld/braze defect though, as 2022M550i mentions.

Ok, I missed that. It's just something I've never heard of.
Which is why I mentioned some mods or other repair requiring the rail removal.
Seems like this is a isolated incident though as none of us have heard of this.

[G30M]

Originally Posted by ProjektAutoScott

Approximately 30,000.

Yeah, I get that take. The V8s certainly aren't for everyone.

Some in the industry will develop strong negative feelings for any engine or car that ever gave them a hard time. My negative feelings are associated more with owners who don't understand or care for their cars.

In my experience a V8 beyond the first gen N63/S63 is totally manageable. I personally wouldn't hesitate to own a well maintained N63TU or newer V8. The V8s certainly come with more to care for, but that is the nature of additional cylinders and an extra engine bank.

For example, this fuel leak doesn't necessarily have to do with a V8 or I4/I6. Rather, the manufacturer who is producing these fuel rails for BMW. Likely Bosch. This type of fuel rail construction is very common across countless makes and models of direct injection engines.

Above all, I am just hoping this fuel leak is an isolated incident.

PSA: If you ever smell raw fuel while driving any modern car, shut it down immediately. With modern closed EVAP and emission control systems, a raw fuel smell is a failure somewhere and you are possibly at risk of fire. When I brought it up, this customer thought nothing was unusual about the intense fumes. Maybe cars just smell like gas, as if the M850i were a car from the 70s with a vented fuel tank and a carburetor.

thanks, that really helps put water on my M5 itch, i think if this car gives me any issue i'm getting an M3 and that will likely be the last pure ICE BMW makes

[430Scud]

Originally Posted by ProjektAutoScott

This is a 2019 M850i. The components in question are shared with the G30 M550i, F90 M5, M8, and the newer X5, X6, and X7 N63 models. This is why I am posting in the more popular G30 forum.

The owner brought the car in for unrelated service. Immediately, I noticed a strong raw fuel odor from the front end of the car in the shop.

In the past, BMW has recalled a number of 2019 N63TU3 cars for leaking high pressure fuel pumps related to incorrect install. I assumed that's where the leak could be.

Strange and more concerning than that, the leak is coming from the non-serviceable junction between the high pressure fuel rail and high pressure injector line for cylinder 1. The leak was not visible without peeling back the factory foam insulation, which was soaked in raw fuel.

See the video for the leak, with the foam pushed back out of the way.

Possibly something to keep an eye on with these newer N63 and S63 powered cars. This M850i has about 30,000 miles on it. Clear ownership and service history. Nothing would indicate this fuel rail has ever been tampered with since production, nor have any of the high pressure fuel components been removed or reinstalled.

Bone stock car. Scary leak considering the fuel soaked insulation napalm, the proximity to heat, and the high voltage ignition/injection components.

https://youtube.com/shorts/c2qjJzeJd...tK18ACKNddM1lz

You should report this:
https://www.nhtsa.gov/report-a-safety-problem#index

[Joe-BMW33]

Originally Posted by 2022M550i

Yep and I remember starting a thread To document issues with our cars Hoping to expose some of the “horror“ stories. Nothing exposed… at least nothing happened with people who belong to this forum.

Now that I have said this, my car will catch fire tomorrow

That was and still is an excellent thread and a great accumulation of data that certainly helps debunk the TU2/3 is unreliable claims and the B58 is more reliable.

I’ve yet to come across a catastrophic failure story or even something trending concerning.