[maddog2020]

Quick summary: my dealer is telling me I need new motor mounts and that they are not covered under CPO - seems ridiculous that a motor mount on a car like this (highly sophisticated mounts) wouldn't be covered.

Long story:

If I accelerate through a left hand corner (only lefts, not rights, only acceleration, not braking or coasting) then the car makes a very nasty and loud grinding sound from the right side. I'm pretty confident (and so is the excellent 3rd party mechanic I use) that it's the inner race on the front right wheel bearing. My dealer put a sound diagnostic kit on the car and diagnosed the steering box, which they replaced under warranty, but of course that wasn't the issue, now they are telling me it's the motor mount and they want $800 to replace it.

Recommendations?

Anyone know:

(a) how to really know if the motor mount is covered under CPO or not?

(b) if I have any recourse if they replace the motor mount and the grinding sound still isn't gone - which I very much doubt it would be?

Thanks.

[knownoknow]

I'm interested in this topic as I'm having the same issue and thought it was the inner lining of the fender of the front pass side wheel well. I trimmed the liner, but it's still loud as ever. Super annoying!

[maddog2020]

Originally Posted by knownoknow

I'm interested in this topic as I'm having the same issue and thought it was the inner lining of the fender of the front pass side wheel well. I trimmed the liner, but it's still loud as ever. Super annoying!

Right, it really sounds like something making contact in there. Only when you give it a bit of throttle in a left turn, correct? So you know, it's been getting worse in my car, happening more frequently, and the grinding much louder.

[locolobo]

I have taken out the passenger side motor mount, as have many others. The procedure is described briefly in a thread by Mik325tds. It is not too hard if you have jack stands and the right tools. Probably you can remove the driver side mount in the same way.

What I discovered when removing it (and accidentally damaging it or finding damage), is that the motor mount is vacuum controlled and has an inflatable bladder inside a plastic cover There are many mounts sold that will fit, but the vacuum one is over $200 for the part.

In my case the plastic casing was cracked and I repaired it and re-installed.

I recommend you read the DPF removal threads on how to remove the passenger side motor mount. , Be sure you really have to replace, before doing it!

[SouthDiesel190]

Originally Posted by maddog2020

Quick summary: my dealer is telling me I need new motor mounts and that they are not covered under CPO - seems ridiculous that a motor mount on a car like this (highly sophisticated mounts) wouldn't be covered.

Long story:

If I accelerate through a left hand corner (only lefts, not rights, only acceleration, not braking or coasting) then the car makes a very nasty and loud grinding sound from the right side.

I experienced the exact same thing and the scenario to replicate the issue was the same as well. My dealer covered the mounts under my CPO warranty and as far as I'm concerned yours should too because of that. I have the documentation of the service already scanned if you want me to send it your way.

[remlemasi]

I had an issue with one engine mount and it wasn't covered as it was "wear and tear" so no CPO.

It manifested itself when idling and at low speeds. Went away at higher speeds.

Ended up buying new engine mounts (both sides) from getBMWparts and having a local Indy change them out for like $150.

[Yozh]

OP. why don't you test your vacuum controlled mounts hold vacuum. Easy to do if you have jack/stands, 8mm socket wrench and a hand vacuum pump with a gauge. Or you can do it from under the hood if you know where the EUV for the mounts is and disconnect there at the outlet, will test both mounts and lines to them.

[Barmlot]

I can verify that my motor mounts were NOT covered under CPO warranty. They are considered a "wear" item. As relemasi said it should be obvious if your mounts are bad when idling/in park. I had A LOT of vibration that went away once the mounts were replaced. Showing up only in a turn definitely sounds like something else to me. Good luck convincing the dealer of that.

[supermann125]

I also have a noise when accelerating in left hand turns. Almost sounds like a rubbing, I thought maybe it was the shocks getting to the bump stops and making some horrid noise. But come to think of it, it's only left turns.

[Mark M]

Originally Posted by supermann125

I also have a noise when accelerating in left hand turns. Almost sounds like a rubbing, I thought maybe it was the shocks getting to the bump stops and making some horrid noise. But come to think of it, it's only left turns.

Could be the traction control.

Hard acceleration combined with a hard left hand turn will instantly trigger the traction control. The ABS module that contains all the pumps / solenoids is located in the right hand side of the engine bay somewhere and easily heard when it is modulating.

[maddog2020]

Originally Posted by SouthDiesel190

I experienced the exact same thing and the scenario to replicate the issue was the same as well. My dealer covered the mounts under my CPO warranty and as far as I'm concerned yours should too because of that. I have the documentation of the service already scanned if you want me to send it your way.

That would be great, I'll pm you my email address so you can send them. The dealer is adamant that they aren't covered.

[maddog2020]

Originally Posted by supermann125

I also have a noise when accelerating in left hand turns. Almost sounds like a rubbing, I thought maybe it was the shocks getting to the bump stops and making some horrid noise. But come to think of it, it's only left turns.

That's how mine started, got progressively worse. The theory on the motor mount is that the mounts are vacuum controlled, and when you load the car up by turning and accelerating it is supposed to increase the stiffness of the mount. If the mount is failing, then it would basically have the motor sitting directly on the frame of the car and the vibration of the diesel would make an awful noise. Honestly, I don't think there is any way in hell it's the motor mount. The noise my car makes is exactly like the sound of a failing wheel bearing. I'm going to have to get the wheel bearing replaced at a local indy shop and carry the cost of it. My indy mechanic is so confident it's the wheel bearing that he says if it's not, he'll do the motor mount for free.

I'm extremely disappointed in the CPO warranty. So far only one thing has been covered under the warranty (the DEF active tank replacement). I really enjoy driving this car, but it's starting to turn into a serious money pit. The basic maintenance costs are so high with the need for fuel filters and all sorts of other stuff that are only required on diesel cars. This is my 4th BMW, and sadly will be my last. Time to sell it and buy a Ford. I must be getting old.

[maddog2020]

Originally Posted by Mark M

Could be the traction control.

Hard acceleration combined with a hard left hand turn will instantly trigger the traction control. The ABS module that contains all the pumps / solenoids is located in the right hand side of the engine bay somewhere and easily heard when it is modulating.

I thought the same thing, but the traction control light isn't kicking on, and the noise is a VERY loud grinding sound. Not inconceivable that it might be solenoid firing rapidly, but it would have to be one hell of solenoid.

[peteyypab]

AHHHHHHH

I complained about this EXACT noise, it's the exhaust hitting the body.

When I complained in warranty sub 50k they said the DP to cat bolts were "loose". But the problem was still there on the hard left accelerations.

I will have to see if I can get them covered in CPO because it's now worse. I get heavy vibrations right over bumps as the suspension compresses. Feel like the motor is bottoming out on the mounts.

Maybe when I bring it in for the airbag recall

[Barmlot]

I'd suggest trying another dealer if you have once close to you, see if they are also certain it's the motor mount.

[peteyypab]

Well I did some additional digging and turns out it's not the exhaust hitting the body.

The motor mount bracket is actually contacting the motor mount housing. I snapped a pic for those that are interested in what's causing the noise.

Dont mind the oil leak that the dealer says isn't there.

[Yozh]

Looks like your mount had collapsed. I would be replacing it.

[Thecastle]

It doesn't look like oil on the mount, looks like soot. Not unusual to have had soot leak, but if your leaking soot, it's probably worth it to find it.

[sukutash]

Originally Posted by Thecastle

It doesn't look like oil on the mount, looks like soot. Not unusual to have had soot leak, but if your leaking soot, it's probably worth it to find it.

Agreed. That's soot not oil.

[maddog2020]

I'm having the motor mounts replaced tomorrow, I'm actually fairly confident after doing some more research that (despite my original post) it is the motor mount. Given that this isn't covered under CPO (what a joke), I'm having it done at a local indy shop, not the stealer.

The reason I'm more confident about the motor mount is that I tried using manual gear selection to keep the revs at different levels while taking the same corner at the same speed and acceleration, and the frequency of the "grinding" appears to correlate with engine revs.

I'll post an update tomorrow if the replacement mount fixes things.

Ian

[Nadir Point]

Originally Posted by maddog2020

My dealer put a sound diagnostic kit on the car and diagnosed the steering box, which they replaced under warranty, but of course that wasn't the issue, now they are telling me it's the motor mount and they want $800 to replace it.

They are probably just indignant about how their high-tech sound diagnosis cost them an expensive, unnecessary repair. Motor mounts are very definitely NOT "wear items" excluded from CPO coverage. I would take my business elsewhere while, assuming you have something from them in writing, opening a case with BMW NA regarding their deceptive business practices.

That is of course, if you have the time to be a vindictive customer from Hell like me.

[Barmlot]

Well maybe I'm not a vindictive customer from hell but I called 3 local dealerships that all told me motor mounts are considered wear items and not included in CPO. Good luck.