Welcome to Tech Talk, where our resident BMW tech Nick Owen answers all your pressing BMW technical questions, frustrations, and issues. Have a question for Nick? Email him at techtalk@roundel.org. Let’s get into it.
Low Speed Vibration
I have a 2015 228i with the six-speed manual transmission and 38,000 miles.
A while ago I started getting a vibration/rumbling at low speeds. Soon the non-emergency “check the driveline” light came on. The dealer did a complete diagnostic test and determined the oil pump needed to be replaced, which we did. They noted the clutch felt marginal and if the light came back it would need to be replaced. After a few days the light came back on and I took it to an independent service center (German Auto} who also did a complete check and confirmed the clutch should be replaced. We did that and they noted the flywheel had some scouring which might have been the cause so they replaced that also. Immediately afterward I felt the low-speed growling and the mechanic felt it was the differential. He put it on the rack to confirm and see what else and said he found metal particles in the differential oil. They replaced the differential with a used unit from a car that had a front-end crash.
Subsequently, there is still the growl and vibration although not as bad. It comes in around 2000-3500 RPM, but then stops. I can run the engine up to 7000 rpm redline in first and second, and push the car up to 85 mph and it runs smooth. I have run the car about another 500 miles without incident.
Do you have a guess on what else it might be? U-joints, tires, suspension damage, etc., before they start guessing at what else to change.
On another but related topic. Your predecessor Mike used to suggest an independent service certification unit (I believe it was BIMRS). There are a couple in northern Virginia but neither are convenient for me. You have not mentioned them and I wonder if it is important to use one of these.
Paul Hopler
This noise you’re hearing, does it happen while under load or off-load? If you can manipulate the noise with the throttle, that will help isolate the source. Where do you hear the noise coming from? Back of the car? Center? Does the noise change at all when taking turns? I wonder if the center support bearing is failing in the driveshaft, that could cause the noise you’re hearing.
As for BIMRS, I was not familiar with them until just now when I searched on Google. I’m not sure exactly what level of service they provide an independent shop that repairs BMWs but it seems they offer a range of training, resources, and knowledge to shops that pay for their membership. In my opinion, these services do not disqualify a shop from being competent at repairing BMWs just because they are not “BIMRS Certified.” I personally would not need their services for my shop because my knowledge and resources are sufficient for me to repair the BMWs that come through the door. I think if you have a good German repair shop you use/trust, then they should be able to help diagnose and rectify this issue you have.
Let me know more regarding the noise.
If I rev in neutral there is no noise. If I pull away in normal mode it is there. However, if I accelerate under full power it seems minimal. When I am in the range of noise, I can’t detect any difference by adjusting the accelerator but if I let up entirely it stops. There is no difference when I am turning. The noise seems to come from the front and I feel the vibration in the steering wheel and a little in the pedals. The bearings is an interesting idea though would the noise/rumbling continue or worsen at higher rpm?
Thanks for the insights on the certification; I will continue as I was.
If the noise/vibration can be felt in the steering wheel then we need to look at the front of the car. The front subframe would have to have been lowered when replacing the oil pump on the initial dealership visit. It’s possible the motor mounts have failed. Or something is not connected/bolted properly. The noise you are describing is strictly under load, therefore someone needs to get in the car while on a lift and load the drivetrain by “power braking” to see if something can be seen while under the car.
Honestly, I would send you back to the dealership since they worked on it for the oil pump and your issue seems to be stemming from that initial visit. However, since other shops have touched the car, it’s possible the dealership will not be of much service but it’s worth asking.
Another N20 Engine Timing Chain Question
I saw your recent response to an N20 timing chain question for a car with a 2014 build date. I am the original owner of a 2016 428i manual transmission coupe with a 01/16 build date. I have meticulously maintained the car, but (now, regrettably) followed the BMW oil change intervals using 0W-20 Mobil 1 synthetic. The car is never tracked and is not driven aggressively. It now has approx. 93,000 miles on it.
Most sources say the timing chain issue was “corrected” by BMW before the 01/16 build date. However, I’ve also read that all N20 engines would be suspect.
My questions:
- Is my engine at risk?
- If so, should I follow your previous response and just watch carefully and wait?
- Any other preventive suggestions?
- How do you feel about switching to 5W-20 (or higher weight)?
Bob Garland, Jr
Charlottesville, VA
While I don’t trust the N20 engine as far as I can throw it, it is possible your engine is okay. The timing chain guide failure tends to happen more on the earlier builds but it’s still a known concern. I think the best thing you can do, aside from wait and monitor the issue, is to check your oil level via the iDrive. This will force the oil pressure solenoid to alter pressure in order to run the oil level check. I’ve found that if this check cannot complete to 100 percent then I would suspect timing chain guide debris is in the oil pickup screen. From there, you could drain the oil and use a borescope to look inside the oil pan to check for debris.
As for oil weight, stick with what the under-hood label says. I suppose you could alternate between 0w-20 and 5w-20 based on climate conditions to help cold start oil pressure but that’s really all the difference it will make.
2014 328 Wheels
The following question should be easy to answer but to my surprise neither the local BMW dealer nor my independent BMW repair shop could. I have four BMW wheels from a 2014 328i xDrive that I want to sell. What other BMW models/years would these wheels fit on?
Steven Christenson
Try using this tool. You will need to know wheel offset, which is stamped behind one of the spokes or the face of the wheel but this should list other models the wheel will fit on. Most BMW lug patterns are 5×120 but offsets vary. There’s a good history of 3 Series wheels being interchangeable to other 3 Series eras.
