Z4M Engine Mounts / Bolts - **ALERT ALL Z4M DRIVERS**

[Bing]

So the thing about those is, whilst the OEM mounts can fail it takes a fair few miles - they'll easily last 100k. This isn't what this thread is about, right ? So I'm not sure about your peace of mind, unless you had the bolts on the mounting plates that the mounts themselves sit on changed at the same time ?

Apologies if I've missed something somewhere else

[srhutch]

So the thing about those is, whilst the OEM mounts can fail it takes a fair few miles - they'll easily last 100k. This isn't what this thread is about, right ? So I'm not sure about your peace of mind, unless you had the bolts on the mounting plates that the mounts themselves sit on changed at the same time ?

Apologies if I've missed something somewhere else

Just looked at flimper pic, and yes it appears the mount bracket bolt is loose, not the mounting bolt itself.

So is it the allure of the mount causing the other bolts to loosen?

[Bing]

According to the BMW SIB that is linked on the first page, excessive heat during manufacturing, at the factory, caused the torque of the bolts to change due to something called 'creep' where metal stretches / moves when it's heated. As far as I understand it, the continued high temperature of the exhaust side of the engine during the car's life causes this creep to continue, which is what has happened in flimper's pic. So I guess that a bolt falls out, others loosen and the weight of the engine and the torque (movement under load) the remaining bolts experience eventually leads to shearing of them. It is NOT the bolts top and bottom of the mounts themselves that fail, it's the bolts holding the plate those mounts sit on that are attached to the chassis and block that fail.

It's a known problem, and some people have successfully claimed recompense for repairs from BMW... I'm not sure what I will do, depend on the cost / hassle of doing so. No warranty, so I can't go that route, probably not worth it.

I haven't had an update today, so I'll give the garage a call tomorrow.

EDIT - can't find the link to the SIB, the ship killer link isn't working and I can't remember where I clicked on it. Will keep trying

EDIT #2 - here's the SIB : https://www.bimmerfest.com/forums/attac ... 1314055257

It's not the same one as I've seen before though, there were pictures in the other one...

Final edit - it's this link from above, has the SIB, info on creep, pics of the mounting plates : http://www.bimmerfest.com/forums/showpo ... stcount=39

[D4dawg]

Ps all my bolts were good
But my rear camber bolts were loose!!

So tightened them
But good to have all checked out:)

[Nictrix]

Are these bolts held in with loctite?
If they are not wouldnt it be a good idea when replacing them to loctite the bolts in and possibly stop it happening again?

[Bing]

Does Loctite have a high resistance to heat ? If not, I doubt it would help much. Given the bolts will have been stressed abnormally all their life, even if they are only loose torquing them back up is probably not enough. Replacing them and torquing the new ones correctly, then checking them regularly, is probably the best way to go.

[craig3.2]

According to the BMW SIB that is linked on the first page, excessive heat during manufacturing, at the factory, caused the torque of the bolts to change due to something called 'creep' where metal stretches / moves when it's heated. As far as I understand it, the continued high temperature of the exhaust side of the engine during the car's life causes this creep to continue, which is what has happened in flimper's pic. So I guess that a bolt falls out, others loosen and the weight of the engine and the torque (movement under load) the remaining bolts experience eventually leads to shearing of them. It is NOT the bolts top and bottom of the mounts themselves that fail, it's the bolts holding the plate those mounts sit on that are attached to the chassis and block that fail.

It's a known problem, and some people have successfully claimed recompense for repairs from BMW... I'm not sure what I will do, depend on the cost / hassle of doing so. No warranty, so I can't go that route, probably not worth it.

I haven't had an update today, so I'll give the garage a call tomorrow.

EDIT - can't find the link to the SIB, the ship killer link isn't working and I can't remember where I clicked on it. Will keep trying

EDIT #2 - here's the SIB : https://www.bimmerfest.com/forums/attac ... 1314055257

It's not the same one as I've seen before though, there were pictures in the other one...

Final edit - it's this link from above, has the SIB, info on creep, pics of the mounting plates : http://www.bimmerfest.com/forums/showpo ... stcount=39

If it's a known issue,BMW should pay up,let's hope so....definitely going to have mine checked.

How are things with you,Bing?

[srhutch]

Problem is with these cars now being 8-10 years old I think there is little chance of them doing anything unless you have a warranty. Even then they won't want to know until your engine is dragging along the road.

[Beedub]

i need to do recheck of these i think....... that Tq figures were surprisingly low for such an important bolt, and they bolts are tiny, i replaced mine on changing the engine mounts.

[Bing]

So the car is done, all mounting plate bolts and the mounts themselves replaced. I'll be picking it up in a couple of hours... After paying the bill - £485 plus VAT

Still, cheaper than it could have been, and now all sorted. Should feel a million times better, I'll let you know later.

[Beedub]

f**k thats alot...... so glad to do a good chunk of my own maintain work, these dealers indies bend us over really...

[Bing]

It an indie. £185 for parts - bolts must be made of platinum - and £300 labour. Lots of work droppingbthebateering rack, lifting the engine, getting that sheared bolt out I guess

I could not have fixed it myself unfortunately.

[Beedub]

It an indie. £185 for parts - bolts must be made of platinum - and £300 labour. Lots of work droppingbthebateering rack, lifting the engine, getting that sheared bolt out I guess

I could not have fixed it myself unfortunately.

i don't think I've read anyone dripping the rack to do these mounts/bolts ?? unless that was needed due to access to the sheared bolt maybe??

[Bing]

It was because of the sheared bolt, they needed to get right in to get it out and make sure the thread was ok.

Looking at the invoice they paid a lot for the new engine mounts... Another £60 and I could have had vibratecs. They also replaced the gearbox mounts as well as the the mount bracket bolts. Most of it was labour, and they'd have done a deal for cash but I want a receipt for something like this. £585 all in... Wheel refurb plans evaporated for a while

But it's fixed, and is silky smooth again. Lovely

[maxman]

As these engines put on the miles it looks like they need an extra level of maintenance ,when you know what's involved and you can do the work yourself or have a workshop you can trust to carry out the work correctly that's fine.Anyone buying one that has just had routine servicing needs to factor in 2K in the purchase price to cover work on the engine bearings plus a roof motor if it's a roadster.
Bing ,the price does not seem to bad as it looks like an awkward job.