Engine mount broken

[billdrage]

My i3 has been diagnosed with a sheared engine mount bolt. It has been with the main agent since 27 March. They have been in touch with BMW technical but have so far not solved the problem. Has anyone had a similar experience?
Collected car today 9th April. They have replaced engine mount and engine support block. Replaced air conditioning pipes band re gassed air conditioning system.
They have no idea what caused the bolt to shear.
The fact that I have no response from the 100 or so visits hopefully indicates that no one has had similar problems.

 

[GodFollower]

This is unfortunately a known issue, although usually it is caused by someone accelerating while one wheel comes off the ground-such as going over a pothole or speed bump, turning over a large lip, etc. The one wheel spins to max speed almost instantly, then when it touches down again all that force causes the drivetrain to rock to it's max position. If this is done repeatedly or in a severe enough manner, it causes one or both of the drivetrain mounting bolts to shear, allowing the drivetrain to move too far and causing damage to other parts around the drivetrain such as A/C lines, wires or modules.

Morale of the story is, don't beat on your i3. Not saying you did, just saying in general

 

[i3atl]

Several people on the Facebook group have had this issue - it has been discussed there in detail. As stated above, it typically happens when the car quickly loses traction while under acceleration.

I think the reason we haven't seen a solution/bulletin yet is because it's not going to be a simple fix long term - as far as I know all they're doing at this point is replacing the bolt/mount (and any other damaged/fatigued components) with replacement parts that are identical to what was used when the car was built.

 

[lownoterider]

Just had the same issue. They told me they are replacing the "motor mount" which could mean many things in a REX I suppose. When I asked "Motor Mount or Engine mount", I think the service advisor's head exploded. She didn't know. But she'll find out and get back to me.

 

[Gonville]

I am very very careful coming off any raised area, kerbs mainly. Speed less than 1mph for this very reason. I read someone gunned it off the kerb as they were on a main highway and didn't want to be rear ended in traffic. Result snapped drive train.

 

[easports82]

Haven't had any problems yet, but I have a habit, for as long as I've been driving, of taking speed bumps on one side of the car. I've heard a little noise and felt a small vibration when the back wheel comes off the bump, but wasn't sure I was causing any damage. Guess I'll be sure to take the bumps head on now.

 

[acpt]

...

I think the reason we haven't seen a solution/bulletin yet is because it's not going to be a simple fix long term - as far as I know all they're doing at this point is replacing the bolt/mount (and any other damaged/fatigued components) with replacement parts that are identical to what was used when the car was built.

I hope this isn't true, I had this problem twice already and so it seems probable to happen again!
I believe you don't need a major bump, because I didn't notice any jump when this occurred.

This problem its a design flaw, that fixing point needs a real reinforcement...

 

[psc]

I wonder if a limited slip diff would help (at least for one wheel airborne) - or redesigned traction control ?

 

[RJSATLBA]

It seems odd that stability control doesn't cut in immediately to prevent the wheel spinning up excessively in the first place.

 

[jadnashuanh]

I played in a snow-covered parking lot one time, and when both wheels are on the snow and you floor the pedal, it barely moves, and the wheels don't appear to spin. I think it does it more via power applied verses braking. It would have to brake a wheel to stop it from spinning. While this is possible, I do not think that it does it under the circumstances.

 

[i3atl]

I hope this isn't true, I had this problem twice already and so it seems probable to happen again!
I believe you don't need a major bump, because I didn't notice any jump when this occurred.

This problem its a design flaw, that fixing point needs a real reinforcement...

What's your car's production date?

 

[dorowe]

My I3 has just under 9,000 miles and this bolt has broken twice - once at just over 4,000 miles and again at just over 8,000. I have agreed with my BMW service garage that I will take the car in for a "lifing" bolt change at another 3,000 miles. It is much easier to change the mounting bolt rather than having to extract the broken part as this requires the sub frame to be dropped.

I agree that this is caused by accelerating whilst cornering/driving over ruts due the torque from the electric motor. Also when the traction control cuts in this can be quite vicious as well.

My I3 is a REX - Do the non-REX I3 have the same issue?

I have no intention of moderating my driving style. This needs a proper engineering fix by BMW, hopefully not by reducing the initial acceleration but by making the mount stronger.

 

[PRCi3]

Darn now I'm going to have to change my driving habits, this thing is way too much fun when the pedal goes down ! :lol: :lol:

 

[dorowe]

Don't lose out on the fun factor. Change the bolt not your use of the go pedal!

Every 3,000 miles?

 

[smyszko]

My REX is in the shop right now for a CEL and a noise coming from the back of the car on right turns. Turns out the noise is due to ... a broken engine mount. That's after just 2.5k of gentle city miles.

IMO there's clearly a design fault here that they need to fix and roll out to everyone.

 

[Sparky]

I am willing to guess this will end in a recall while the numbers are small, and it's in design now.

 

[dorowe]

I believe that is the bolt that is breaking not the mount as such? I assume that it is a big job to fix as the broken end has to be removed from where it locates in the motor - this is the generator not the electric motor.

Is it just the REX that is suffering from this failure?

The other aspect is the mileage that failure occurs at. It will be influenced by driving "style" and road conditions, e.g. driving on main roads would create less stress than country roads or roads with speed humps.

Here's hoping I make 3,000. Approaching 1,000 since the repair and counting !

 

[smyszko]

Sparky, I hope you're right about a recall coming. I don't want to have to baby this car every time I go near a pothole or tree root. The LA roads are surprisingly bad for this kind of thing, but I've never had a problem before.

I suspect a pothole is what caused it on my car btw as I went over a nasty one around the time I first heard the noise from the back of the car. I hit it in the dark on a left hand turn off a set of traffic lights. I was accelerating away from the lights on the turn and the front left clipped it but the rear left went in solidly.

dorowe, I thought I remembered a guy in Norway with a BEV reporting the problem, but can't find the post anymore. When it happened each time for you, what was symptom? Did you get a drivetrain malfunction, power loss, notice a noise or something else?

 

[dorowe]

When the fault happened I just noticed a knocking noise from the rear right that I could create by full acceleration & lifting off. If I was gentle on the throttle I could drive the car without any noise.

No faults were reported by the I3.

 

[jadnashuanh]

The 'no faults' thing is perfectly understandable...it breaking in the first place, is the bad part!

Is this the actual mount, or a bolt, or both? I'd guess if a bolt broke, it could then damage the mount and vice-versa.