[ab1752]

Hi all,

This likely could have been posted in the "issues" thread but it was such a drawn out process to fix I hoped to save others some time and likely money.

I am the original owner of a 2018 M550i which has been mostly trouble free other than a few sets of active grills and a steering rack replacement early on. Earlier this summer, at about 66,000 kms, I started to note a shudder, particularly on what I would consider to be light to medium throttle. It became annoying enough that my kid who is notoriously buried in his phone noticed so off to BMW it went. I had noticed it for a while but wasn't able to duplicate it when a tech was in the car until now as it was very obvious there was an issue.

I was thinking torque converter or xDrive so they pulled the xDrive relay and flashed the SW, stating it is now smooth as silk...except it wasn't. They also said the tires installed last year on the factory 20's, in the same as the OE Michelin non-rfts could be causing the issue. I had to snag the "non BMW" stamped Michelins due to supply chain circus so to rule those out, a set of 19's RFT OE's was installed. Smooth as silk...except it wasn't again.

So after a 1,200km road trip, I booked it back into BMW on the following Monday. The Saturday before, the "Drivetrain Malfunction" warning flashed twice with limited power so yaahoo...now we have some codes to work with pointing at fuel pressure issues. BMW asked for the tank and the low pressure fuel pump to be replaced, and we had to wait another three weeks for a new pump. Oh and a new harness has to be spliced in as BMW does not supply the same version of pump as the factory original for 2018's, at least.

I picked the car up last night and it seems to be all good to go now. There was a ton of time spent diagnosing this issue so if your car starts running rough, and throws fuel pressure codes, I think you can bypass the tank replacement and aim directly at the low pressure pump. I am hoping this is behind me now and this info helps others with similar issues. Cheers.

[Mandingo9]

Originally Posted by ab1752

Hi all,

This likely could have been posted in the "issues" thread but it was such a drawn out process to fix I hoped to save others some time and likely money.

I am the original owner of a 2018 M550i which has been mostly trouble free other than a few sets of active grills and a steering rack replacement early on. Earlier this summer, at about 66,000 kms, I started to note a shudder, particularly on what I would consider to be light to medium throttle. It became annoying enough that my kid who is notoriously buried in his phone noticed so off to BMW it went. I had noticed it for a while but wasn't able to duplicate it when a tech was in the car until now as it was very obvious there was an issue.

I was thinking torque converter or xDrive so they pulled the xDrive relay and flashed the SW, stating it is now smooth as silk...except it wasn't. They also said the tires installed last year on the factory 20's, in the same as the OE Michelin non-rfts could be causing the issue. I had to snag the "non BMW" stamped Michelins due to supply chain circus so to rule those out, a set of 19's RFT OE's was installed. Smooth as silk...except it wasn't again.

So after a 1,200km road trip, I booked it back into BMW on the following Monday. The Saturday before, the "Drivetrain Malfunction" warning flashed twice with limited power so yaahoo...now we have some codes to work with pointing at fuel pressure issues. BMW asked for the tank and the low pressure fuel pump to be replaced, and we had to wait another three weeks for a new pump. Oh and a new harness has to be spliced in as BMW does not supply the same version of pump as the factory original for 2018's, at least.

I picked the car up last night and it seems to be all good to go now. There was a ton of time spent diagnosing this issue so if your car starts running rough, and throws fuel pressure codes, I think you can bypass the tank replacement and aim directly at the low pressure pump. I am hoping this is behind me now and this info helps others with similar issues. Cheers.

So this car likes it's fuel hopefully this fix sticks.

[adhrp]

This thread came up as I was doing a search. Been hearing a loud whine as the pump primed upon unlocking my car (2020 M550i). Last week, on start up, my car shuddered, threw a drive train malfunction, and shut down. It started alright a few seconds later but I felt that the power had decreased. Dealer read the codes and turns out the low pressure fuel pump malfunctioned, which was replaced under warranty at 39k miles. Luckily, it only took 3 days for the part to arrive.

[ab1752]

So with my car, that annoying shudder remained. 2 weeks ago, check engine light comes on, and it's a vanos solenoid. Not sure if it was intake or exhaust, but when it was pulled apart, I paid for the other one. Finally, that annoying shudder seems to be gone...makes sense if vanos on one side was late to engage. Wonder what's next.

[adhrp]

Glad this was resolved. Assuming your car is under warranty since it appears you paid for the other one preemptively? Sounds like this was a misdiagnosis from the start, so hopefully this was the only 'real' issue and that your car stays solid moving forward.

[ab1752]

It is. Not much happened during the original 4 year but when I couldn't make up my mind what to buy next, i added a 2 year "bmw" extended warranty. This picked up the epic fuel pump adventure, yet another set of grills and the labor / single vanos solenoid. The other one was only 90 bucks and there was a mountain of solenoids in stock so it made sense.

I'm a big fan of this car. They have 3 my22 brand new m550is in stock they keep trying to sell to me but no b&w and the lease residual is stunningly lower now so I'm fine with this one for now.