E46 Boot Floor Cracks

[dr_gn]

Guys,

I had a good poke around under mine (2002 330i Sport) last night, and can't find any cracks. There are patches of surface rust around where the rubbers fit to the body, but no lines that I can see. Presumably if there are cracks, they're pretty obvious?

Having read a statement from BMW on another forum, they mention filling with foam, presumably to stiffen the cavity above where the mounts are - is this a good preventative measure to stop the cracks starting?

Are there any other preventative measures that can be taken to stop the cracking problem (or at least reduce the risk)?

Does anyone have a link to the current statistics (year, type, mileage) for cars that had a problem? I can't find the right poll thread on the E46Fanatics forum.

Cheers.

[dr_gn]

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

According to most other sources, it absolutely doesn't only apply to M3's etc., nor does it apply only to cars up to 2000 when BMW supposedly introduced a mod to the boot floor.

I admit I'm a bit paranoid, but can't see why asking about how you could - possibly - prevent an expensive repair is unreasonable, especially if preventative maintenance on the cooling system is 'fair enough'.

[dr_gn]

St John Smythe said:

dr_gn said:

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

According to most other sources, it absolutely doesn't only apply to M3's etc., nor does it apply only to cars up to 2000 when BMW supposedly introduced a mod to the boot floor.

I admit I'm a bit paranoid, but can't see why asking about how you could - possibly - prevent an expensive repair is unreasonable, especially if preventative maintenance on the cooling system is 'fair enough'.

It's a ten year old BMW. Plus you've already said you can't see any cracks? I've had a 330ci, Z4 and now have an e46 B3. Never had any problems with subframe cracks and I've never heard of anyone else having them either. Take it into a specialist and get them to health check the car if you're that worried!

You've never heard of anyone else having them either? Do a Google search!

I'm sure there are thousands of cars without cracks, thousands with cracks, and thousands more that will never be checked.

Yes, it's a ten year old car worth about £3k, but it's my first BMW, and it's nice to be fore warned and fore armed as to what could happen.

[dr_gn]

St John Smythe said:

dr_gn said:

St John Smythe said:

dr_gn said:

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

According to most other sources, it absolutely doesn't only apply to M3's etc., nor does it apply only to cars up to 2000 when BMW supposedly introduced a mod to the boot floor.

I admit I'm a bit paranoid, but can't see why asking about how you could - possibly - prevent an expensive repair is unreasonable, especially if preventative maintenance on the cooling system is 'fair enough'.

It's a ten year old BMW. Plus you've already said you can't see any cracks? I've had a 330ci, Z4 and now have an e46 B3. Never had any problems with subframe cracks and I've never heard of anyone else having them either. Take it into a specialist and get them to health check the car if you're that worried!

You've never heard of anyone else having them either? Do a Google search!

I'm sure there are thousands of cars without cracks, thousands with cracks, and thousands more that will never be checked.

Yes, it's a ten year old car worth about £3k, but it's my first BMW, and it's nice to be fore warned and fore armed as to what could happen.

If you Google any car you'll find examples of problems! I'm talking from my real world experience with the cars I've owned and M3s and 330cis that mates have. As I said before, take it to your local specialist if you're that worried. They'll check the whole car over for you which is much more helpful then googling for 'possible'problems.

If you don't know the answers to my questions, it's fine

It's not a 'possible' problem, it's a known design fault with the E46. When they crack depends, among other things, on the spec. of the car, how old it is, how it's been driven, over what quality of road surface and over how many miles. Mine doesn't have any cracks yet (at least not visible ones), but, assuming it continues to accumulate miles, eventually it will, whether in my ownership or not.

All I'm asking is, is there any preventative measures to delay or prevent the cracks appearing or propagating? I was intrigued by BMW's foam cavity filling fix. At the end of the day if it turns out to be a good car, and it does crack, it'll get repaired. I'm well aware that the cracks won't appear overnight to the degree that the subframe falls out.

[dr_gn]

St John Smythe said:

Blair357ci said:

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

Wrong it affects all E46's

I didn't say it didn't. What I did say is it is far more likely to affect M3s. So not wrong at all.

Can you provide statistics to back that statement up?

According to these 2008 figures from an E46Fanatics poll, M3's hardly register. OK, maybe less M3 owners submitted their votes, but, in general, it's the early versions of the car that were affected irrespective of type. Of course, as the years pass, more of the newer types are showing problems. This is the reason I asked for current statistics: to make a more informed judgement of the problem.

By Model
323i 24
323ci 52
323iT 1
325i 1
325ci 3
328i 47
328ci 64
330i 1
330ci 4
320D 1
m3 5

By Year
NA 10
1999 46
2000 134
2001 6
2002 6
2003 1
2004 1

Total 206

[dr_gn]

St John Smythe said:

dr_gn said:

St John Smythe said:

dr_gn said:

St John Smythe said:

dr_gn said:

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

According to most other sources, it absolutely doesn't only apply to M3's etc., nor does it apply only to cars up to 2000 when BMW supposedly introduced a mod to the boot floor.

I admit I'm a bit paranoid, but can't see why asking about how you could - possibly - prevent an expensive repair is unreasonable, especially if preventative maintenance on the cooling system is 'fair enough'.

It's a ten year old BMW. Plus you've already said you can't see any cracks? I've had a 330ci, Z4 and now have an e46 B3. Never had any problems with subframe cracks and I've never heard of anyone else having them either. Take it into a specialist and get them to health check the car if you're that worried!

You've never heard of anyone else having them either? Do a Google search!

I'm sure there are thousands of cars without cracks, thousands with cracks, and thousands more that will never be checked.

Yes, it's a ten year old car worth about £3k, but it's my first BMW, and it's nice to be fore warned and fore armed as to what could happen.

If you Google any car you'll find examples of problems! I'm talking from my real world experience with the cars I've owned and M3s and 330cis that mates have. As I said before, take it to your local specialist if you're that worried. They'll check the whole car over for you which is much more helpful then googling for 'possible'problems.

If you don't know the answers to my questions, it's fine

It's not a 'possible' problem, it's a known design fault with the E46. When they crack depends, among other things, on the spec. of the car, how old it is, how it's been driven, over what quality of road surface and over how many miles. Mine doesn't have any cracks yet (at least not visible ones), but, assuming it continues to accumulate miles, eventually it will, whether in my ownership or not.

All I'm asking is, is there any preventative measures to delay or prevent the cracks appearing or propagating? I was intrigued by BMW's foam cavity filling fix. At the end of the day if it turns out to be a good car, and it does crack, it'll get repaired. I'm well aware that the cracks won't appear overnight to the degree that the subframe falls out.

Nope, it is a possible problem sorry. Otherwise every e46 out there would have cracks and they don't. Speak to a specialist. Try Phil Crouch at CPC.

Please re-read what I wrote

[dr_gn]

St John Smythe said:

dr_gn said:

St John Smythe said:

Blair357ci said:

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

Wrong it affects all E46's

I didn't say it didn't. What I did say is it is far more likely to affect M3s. So not wrong at all.

Can you provide statistics to back that statement up?

According to these 2008 figures from an E46Fanatics poll, M3's hardly register. OK, maybe less M3 owners submitted their votes, but, in general, it's the early versions of the car that were affected irrespective of type. Of course, as the years pass, more of the newer types are showing problems. This is the reason I asked for current statistics: to make a more informed judgement of the problem.

By Model
323i 24
323ci 52
323iT 1
325i 1
325ci 3
328i 47
328ci 64
330i 1
330ci 4
320D 1
m3 5

By Year
NA 10
1999 46
2000 134
2001 6
2002 6
2003 1
2004 1

Total 206

206 out of how many built?

Who cares?

Of all the E46 owners in the world, how many people actually go and check and subscribe to a forum poll?

The point is that the distribution of the 206 cars in the poll indicates that it is by no means limited to M3's (as you said it was earlier).

[dr_gn]

St John Smythe said:

dr_gn said:

St John Smythe said:

dr_gn said:

St John Smythe said:

Blair357ci said:

St John Smythe said:

Seriously, I saw your other thread on preventive maintenance which is fair enough but I wouldn't worry about cracks in your boot floor (especially because you've checked and can't see any!). This only really affected M3s and higher powered e46s (Alpinas, etc). Just enjoy the car and stop trying to find something wrong with it!

Wrong it affects all E46's

I didn't say it didn't. What I did say is it is far more likely to affect M3s. So not wrong at all.

Can you provide statistics to back that statement up?

According to these 2008 figures from an E46Fanatics poll, M3's hardly register. OK, maybe less M3 owners submitted their votes, but, in general, it's the early versions of the car that were affected irrespective of type. Of course, as the years pass, more of the newer types are showing problems. This is the reason I asked for current statistics: to make a more informed judgement of the problem.

By Model
323i 24
323ci 52
323iT 1
325i 1
325ci 3
328i 47
328ci 64
330i 1
330ci 4
320D 1
m3 5

By Year
NA 10
1999 46
2000 134
2001 6
2002 6
2003 1
2004 1

Total 206

206 out of how many built?

Who cares?

Of all the E46 owners in the world, how many people actually go and check and subscribe to a forum poll?

The point is that the distribution of the 206 cars in the poll indicates that it is by no means limited to M3's (as you said it was earlier).

Exactly! But you're the one that actually posted about the poll? Plus I never said it was just limited to M3s, I said they were most likely to be affected.

Judging by your posts you are obviously concerned about the condition of your car. A specialist will provide you with a workshop report detailing anything that needs doing and may need doing in the future plus peace of mind. It's what I've done with my Alpina and I've nearly got it tip top Plus a specialist will be able to advise you on any questions you have. On forums you'll end up with different opinions going round in circles. That's my advice anyway and I've owned a fair few cars. Take it or leave it

Huh? If that poll shows anything (which OK, is questionable, but FWIW), it's that M3's pretty much *aren't* most likely to be affected!

I'd bet a significant amount of money that if you put 100 E46's on test rigs, loaded them to simulate various driving conditions, eventually they'd ALL develop cracks whether it be at the equivalent of 60k miles, 100k miles of 500k miles. It's a design fault. Fatigue will always win in the end unless you drive like a nun all the time.

I'd describe my car (touch wood) as almost unbelievably good, I don't need to take it to a specialist (yet!), all I'm asking is...well, read my first post.

[dr_gn]

corvus said:

I obtained this from the March edition of Total BMW magazine

http://www.redish-motorsport.com/E46M3FloorSubfram...

You might want to take a deep breath before you see the price, especially as you don't have any cracks as yet. They do say that changing the standard subframe bushes for polybushes can help, as the different shape of the polybush puts less stress through the floor.

Not worth worrying about though unless there are cracks appearing.

Yeah, thanks I've got that magazine. I had a good idea of the cost of repairs before I bought the car (I think that figure is top of the tree TBH). I was pretty confident mine wasn't cracked anyway.

ALL I was asking here really was about preventative measures. As I said, if it turns out to be a keeper, the cost of repair is fine.

[dr_gn]

Thanks guys, that's more like it

Presumably the foam/sealant is to form a sandwich between the upper and lower boot floor membranes and stiffen it up/spread the load out a bit? Would be up for DIY no problem.

BMW specify a pretty detailled procedure as a fix, but has anyone here experience of actually doing it?

[dr_gn]

jaedba2604 said:

this thread was getting a bit like a film i once saw, micheal caine, jude law, slueth...if you's get me...

Now I feel old: the version of that film I saw had Michael Caine and Laurence Olivier.

[dr_gn]

jaedba2604 said:

dr_gn said:

Thanks guys, that's more like it

Presumably the foam/sealant is to form a sandwich between the upper and lower boot floor membranes and stiffen it up/spread the load out a bit? Would be up for DIY no problem.

BMW specify a pretty detailled procedure as a fix, but has anyone here experience of actually doing it?

yep, it was something to do with torsional rigidity, you had to leave it for 24 hours to harden off.

if you look on m3cutters you'll see lots of people have had sub frame issues. being cognisant of the fact that people always post problems so it will look worse than it is...

I wonder if you put the foam in, it screws any chance of you adding a welded repair later (if it becomes necessary)?

Some of the welding is from above, inside the cavity.

[dr_gn]

jaedba2604 said:

dr_gn said:

jaedba2604 said:

dr_gn said:

Thanks guys, that's more like it

Presumably the foam/sealant is to form a sandwich between the upper and lower boot floor membranes and stiffen it up/spread the load out a bit? Would be up for DIY no problem.

BMW specify a pretty detailled procedure as a fix, but has anyone here experience of actually doing it?

yep, it was something to do with torsional rigidity, you had to leave it for 24 hours to harden off.

if you look on m3cutters you'll see lots of people have had sub frame issues. being cognisant of the fact that people always post problems so it will look worse than it is...

I wonder if you put the foam in, it screws any chance of you adding a welded repair later (if it becomes necessary)?

Some of the welding is from above, inside the cavity.

don't really know, i think that the plates were welded around the sub frame mounts, not sure where or how.

i suspect that if you've injected and then it goes, you're in write off territory..

Ta. This might be useful to some people, its from the E46zone forum, credit "Sam". It is out of date now of course, but outlines what the official BMW angle was on the issue:

http://e46zone.com/Admin/Sam/e46_subframe_tis.pdf

[dr_gn]

Just got back from Sytner BMW to exchange the water pump. Had a chat to the service manager while I was there, and he reckoned they'd only had 2 or 3 in for repair (1 saloon), the others coupes. They repaired them with the foam method in the BMW bulletin. He confirmed the 10 year cut off, but was a bit vague about the necessity to have a full BMWSH. I got the impresion that it was not a pre-requisite to getting it done under some form of manufacturer's agreement.

He also offered to put mine on the ramp and have a quick look, so with some trepidation I accepted. He said it all looked fine, and if it hadn't gone at 69k it probably wouldn't.

Apparently the epoxy foam repair kit is still available from BMW.

[dr_gn]

St John Smythe said:

dr_gn said:

Just got back from Sytner BMW to exchange the water pump. Had a chat to the service manager while I was there, and he reckoned they'd only had 2 or 3 in for repair (1 saloon), the others coupes. They repaired them with the foam method in the BMW bulletin. He confirmed the 10 year cut off, but was a bit vague about the necessity to have a full BMWSH. I got the impresion that it was not a pre-requisite to getting it done under some form of manufacturer's agreement.

He also offered to put mine on the ramp and have a quick look, so with some trepidation I accepted. He said it all looked fine, and if it hadn't gone at 69k it probably wouldn't.

Apparently the epoxy foam repair kit is still available from BMW.

Good news

For now

[dr_gn]

Blair357ci said:

dr_gn said:

Just got back from Sytner BMW to exchange the water pump. Had a chat to the service manager while I was there, and he reckoned they'd only had 2 or 3 in for repair (1 saloon), the others coupes.

I would guess he's not being entirely truthful... Like when I picked my 120d up from my local Sytner after PDC failure they were telling me they had never herd of the fault before & the customer at the next desk lent over saying that's funny you've replaced mine & my wife's.....

Quite possibly true.

Then again he could have just sucked his teeth when I said it wasn't FBMWSH.

Plus he offered to have a look at it for me on the ramp - I didn't ask him. If he'd a found anything, since the car isn't *quite* ten years old he'd had pretty much committed himself to take some action over it (he previously said the cut-off for repair was ten years - not ten years and a day, and didn't seem too bothered about a full history).

All things considered they were extremely helpful, both in the parts dept (10% discount for an old car) and the service dept. Especially considering I didn't buy the car (or any car) from them in the past.

As a last resort now, I might just have to go ahead and enjoy driving it.

[dr_gn]

edc said:

Blair357ci said:

dr_gn said:

Just got back from Sytner BMW to exchange the water pump. Had a chat to the service manager while I was there, and he reckoned they'd only had 2 or 3 in for repair (1 saloon), the others coupes.

I would guess he's not being entirely truthful... Like when I picked my 120d up from my local Sytner after PDC failure they were telling me they had never herd of the fault before & the customer at the next desk lent over saying that's funny you've replaced mine & my wife's.....

I'm not surprised BMW don't seem many for repair. Imagine the cost vs Indy and who really services an E46 at a dealer now anyway?

That thought crossed my mind, but the BMW repair was free apparently if the car is less than ten years old. They seem to work on a case-by-case basis, so I guess if you went in all guns blazing you'd probably get nowhere, but if you'd already resigned yourself to forking out for a repair and went for advice or an inspection, it could well have been (or might still be) f.o.c.

[dr_gn]

edc said:

Can you find any suggestion that this policy still exists.

No, and unless mine fails before 30th Septemer this year, I won't be eligible either way.

TBH on any ten year old car, if I were a main dealer I'd say 'hard luck'. It's probably a goodwill / good publicity gesture more than anything even though it's pretty clear it's a design fault. Then again who knows how the cars that failed were driven?

[dr_gn]

Blair357ci said:

dr_gn said:

No, and unless mine fails before 30th Septemer this year, I won't be eligible either way.

TBH on any ten year old car, if I were a main dealer I'd say 'hard luck'. It's probably a goodwill / good publicity gesture more than anything even though it's pretty clear it's a design fault. Then again who knows how the cars that failed were driven?

Members on e46zone & M3cutters have had cars repaired this year by BMW

No mention was made of welding BTW - they said today the repairs were by injecting epoxy foam.

[dr_gn]

jaedba2604 said:

dr_gn said:

No mention was made of welding BTW - they said today the repairs were by injecting epoxy foam.

i understood they put in a whole new subframe at the dealer, diff design.

I've heard boot floor too, so that's three possible 'fixes'.