[Serf27]

Just making this to share with everyone.
I was replacing my front wheel bearing today and looking around for anything loose that might be creating some clunking noises I had.
I pushed the engine mount and it slightly moved. Sure enough, both bolts that hold the mount to the subframe were missing. Checked the other side and those were gone too.

I put all 4 new bolts and almost all if not all the noises have stopped.

[e90yyc]

But there’s only four bolts total between the two sides. Are you saying your engine mounts weren’t bolted to the subframe at all? If so, damn. And nice catch. I love those fixes where it’s something totally unexpected but easy and actually solves the issue.

My theory is that someone tried to steal your engine but couldn’t lift it out so they had to bail.

[Serf27]

Yes, they weren’t bolted at all. Only the top nuts securing the engine to the mounts were there. The other 4 bolts were no where to be found.
Yea, pretty sweet fixing one issue and seeing something else randomly that fixed a lot of other issues.

Haha! My theory is the previous owner really needed the bolts when he sold the car so he took them off. Or they were loose and rattled off. The threads are about 2” long too.

[gbalthrop]

Originally Posted by Serf27

... Sure enough, both bolts that hold the mount to the subframe were missing. Checked the other side and those were gone too...

Has your oil sump gasket ever been replaced, and if so, by WHOM? Some "Mek-nik" probably wondering WHERE those four bolts came from.
George

[Serf27]

Originally Posted by gbalthrop

Has your oil sump gasket ever been replaced, and if so, by WHOM? Some "Mek-nik" probably wondering WHERE those four bolts came from.
George

That may have happened too.
I did see the bolt heads for the rack and pinion had been messed with because they had some wear/marks on them. Someone definitely did some work down there.

[IllSic_Design]

Wow, very good catch!!

[AWDBooSTIn90]

Originally Posted by gbalthrop

Has your oil sump gasket ever been replaced, and if so, by WHOM? Some "Mek-nik" probably wondering WHERE those four bolts came from.
George

That's probably actually deff what happened. Has to be. Crazy man.

[Serf27]

Symptoms of no bolts on the engine mounts included:
Loud rattle over certain bumps from the left side of the car, mainly left rear.
Quick rattle at start up
Car jerking at low speeds when downshifting automatically.
Popping/clucking when shifting between forward and reverse. (Even after new control arms)
Unusual vibrations in the steering wheel (even after wheel rebalance and alignment)
Rattle/clucking when entering driveways.

Now I’m not sure if ALL of those issues were from that. I’ll say after putting new bolts and driving it 35 miles city over various roads, I haven’t heard any of those noises.
Check your bolts!

[eljay]

Ouch!! And nice catch and save!

Some of us here are worried about whether to re-use bolts, what's the torque, do we put antiseize, Loctite, blinker fluid on all the fasteners... and all along the answer is simple: we don't need no stinkin' bolts!

Back on serious note: I would also check the front driveshaft guibo area. If the engine was "jumping around" in its cradle, some wear may have been introduced in the places that don't expect that kind of a flex.

[tcphoto]

Good catch, imagine if you suddenly got the itch to take it to the track...

[e90yyc]

Originally Posted by gbalthrop

Has your oil sump gasket ever been replaced, and if so, by WHOM? Some "Mek-nik" probably wondering WHERE those four bolts came from.
George

Could also have been a “Mek-neck”—a redneck mechanic who doesn’t believe in bolts because his father never used them.

[gbalthrop]

Originally Posted by Serf27

Symptoms of no bolts on the engine mounts included: ...

As long as you don't NOW have a "Domed Hood", you caught it in time.

A quick way to tell if you have a bad Motor Mount on ONE side:
1) Open Hood, Set Parking Brake, Start Engine, Put in R and press Throttle AND Brake (MT owners, be creative/Safe ;-);
2) Observe AMOUNT of Lift on either side of engine;
3) Change to D and repeat. Opposite side of engine should Lift. Compare amounts.
Crankshaft rotates Clockwise as viewed from Front. Driveshaft Rotation direction (attempted) changes between R & D.

If One side lifts more than other with same Torque applied to Drive Shaft, the Motor Mount on that side is suspect. NOT sure IF/ How Well this works with x-Drive. In OP's case, BOTH sides should have shown excessive "Lift" from engine torquing on mounts in BOTH "attempted" rotation directions.

IF ANYONE gets different results, please feel free to enlighten me.
George

[cFL21]

From what I've seen the engine mount has just one bolt for each. I've just discovered today mine has the nut missing on both sides. Will fix it asap. I wonder if this could be the problem of the hard knock and car shake when I take sharp turns, it sounds and feels like the engine it's gonna go of the car. Does anyone know the nut size for the bolts?

[gbalthrop]

Originally Posted by cFL21

From what I've seen the engine mount has just one bolt for each. I've just discovered today mine has the nut missing on both sides... Does anyone know the nut size for the bolts?

You don't say what Engine or Model E90 you have. Here is a link to the Engine Mount parts on my 3/2007 build 328xi:
https://www.realoem.com/bmw/enUS/sho...diagId=22_0113

Since YOURS may differ, you should go to this RealOEM.com link and enter the Last-7 Characters of your VIN, to see correct parts for YOUR vehicle:
https://www.realoem.com/bmw/enUS/select
If you are NOT in US, or prefer a language OTHER than English, you can change page.

You appear to be talking about the NUT on the Stud on top of the rubber engine mount, Item #6 for my 328xi, which is a "07119904670 Flange nut M10-10-ZNS3" per this page:
https://www.realoem.com/bmw/enUS/par...&q=07119904670

My understanding is that OP was talking about the two Bolts (Item #8 on my car), that hold the Engine Mount bracket to the Subframe. If referring to the correct RealOEM.com page for YOUR car ("22 Engine & Transmission Suspension") does NOT answer your questions, please post back, AND Provide Last-7 Characters of your VIN.
George

[Serf27]

My car was missing all 4 no8 bolts from the realoem link.