[jwh335i]

I bought my M340i in May of 2019. After a couple of years, I noticed a rattling sound from the engine when you run the oil level check. I did complain to the dealer (Crevier), predictably they said they could not replicate it. So now after another year plus, the motor makes the same rattling noise while driving when you stop at the light and take your foot off the brake. It does sound like it is at the firewall, which in my mind points to the timing chain -- that being a huge problem as the engine must come out to service. Anyhow, since my warranty is up in one month I will take it one more time to the dealer and not take no for an answer this time, the motor absolutely rattles during the oil check and at lights. But I am curious if others have this problem. At the lights it is just a brief rattle, it is more prolonged during the oil check procedure.

The other issue is harder to reproduce: on especially cold mornings as I back down my driveway and turn the wheel to get on the road, the front end makes a loud pop, you feel the steering wheel and tires shift. I did complain about this as well to Crevier as well and got the same bs about them not being able to replicate it.

What I worry about is that the vehicle has some sort of ticking time bomb not only in the engine but also in the steering/suspension. And now my warranty is up in a month. Damn BMWs... The vehicle was $68,000 and has had assorted issues: they had to replace one of the laser headlights ($3000 just for the headlight not including labor!) and both the drivers side and passenger side mirror assemblies. So now when you add in the rattle and the popping noise, I kinda wish I had leased.

[hankcah]

You should take your car to be looked at by an independent shop that specializes in german sports cars. I notice a ton in the Newport area.

When you have it in writing of what's wrong, then you can take that to your dealership, along with your dates you already brought up the issues to them and say you want this resolved and you're contacting BMWNA. When they resolve the issue, I'd send them the bill for what the other shop charged you. Just because they couldn't reproduce it, doesn't mean it's not an issue. They could've driven it to your house and asked to reverse it while they drove. It's a game with these dealerships.

[jwh335i]

it has been a week now, the dealer has still not determined the cause of this knocking sound during the oil measurement procedure.

[jwh335i]

The dealer indicates that the oil pump was the source of the knocking sound. The oil pump on the B58TU is a variable displacement pump so it pricey. I also have the xdrive so the differential and CV axles must be removed along with the control arms/tie rods/subframe. After all that is out, they can remove the oil pan and access the oil pump. I wonder what this would have cost outside of warranty, surely something scandalous.

I do like the car but this has soured me on BMWs. Between the replacement of the laser headlight, both the drivers side and passenger side mirrors, and now the oil pump, makes me worry about the future for this 2020 M340i I bought. I have meticulously maintained the vehicle, BMW certified oil changes every 5000 miles and kept it spotless, including the engine bay. So it is not for lack of maintenance. I have never launched the vehicle either although I am not shy about the gas pedal, if you didn't want to floor it, why get the M340i?

What is funny is I had a similar long list of repairs (both turbos, all the injectors, and on and on) on my 335i. But I was convinced that BMW ironed out their problems finally with the B58TU engine. Fool me once, fool me twice now.

I also worry about the longevity after such a major repair. The oil pump is installed with torque-to-yield bolts. It has to be done properly. The CV axle on the one side also passes through the oil pan so it has to be sealed properly. The only bright side is that the oil pan gasket in BMWs is virtually guaranteed to leak after 8 years or so so now I get to reset the clock on the leaks.

[jwh335i]

I finally got the vehicle back, it took 15 days. I wonder how many other M340i's have this problem in which a rattling sound comes from the engine during the oil measurement procedure. I was worried that it was the timing chain but it would appear that replacing the oil pump has done the trick, I don't hear the rattling noise anymore.

[jwh335i]

So after replacing the oil pump, the car made the rattle the next day. I took it back to the dealer, they verified and kept car. After another week, they replaced the DSC module. It has not fixed the vehicle. It now has been since April 10th that the dealer has had the vehicle to no avail. What is surprising to me is how the repairs have been performed: 3 times now, they throw parts at the car to see if it will fix it. This is not professional in my opinion, I would be guilty of such an approach, it is the hallmark of a shade-tree mechanic. Throw parts at it and hope for the best.

So after $3000 worth of parts and at least that in labor, we are back to square one: the engine has a rattle. What a godawful waste of money, it is what I told them in the beginning: it is either the timing chain or the valve train, either way that engine must come out. But the BMW TSE is not there to help the BMW owner, he is there to protect BMW and so only authorizes half-assed repairs rather than biting the bullet and doing what needs to be done.

The saga continues....

[JacobM340i]

Post a video of the rattle

[merv1]

Any update on the rattle or how they fixed it?