E46 330i - how to check boot floor for cracks?

E46 330i - how to check boot floor for cracks?

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MajorMantra

Original Poster:

1,265 posts

111 months

Sunday 23rd April 2017
quotequote all
I might be looking at an E46 330i Touring this week. I'm aware of the boot floor/subframe mounts issue, but what I'm struggling to find out is whether it's possible to check for it without getting the under car.

Is checking in the boot sufficient?

mark.c

1,090 posts

179 months

MajorMantra

Original Poster:

1,265 posts

111 months

Sunday 23rd April 2017
quotequote all
Seen that, but it doesn't answer my question. Clearly you can check underneath, but I'd like to know if one can learn anything useful without a ramp. I'm not convinced a small dealer will let me get that up close and personal with the car's underside...

bmwmike

6,918 posts

107 months

Sunday 23rd April 2017
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I've had a e46 and turned out to have a 25mm hairline crack next to one of the mounts. There was nothing visible inside the boot whatsoever. The boot floor is double skinned where they cracking so in my case the bottom skin was cracked and top was not. The fix resulted in new boot floor and that was visible inside boot IIRC as it seemed to have new sealer etc. Point is boot side was fine.

E-bmw

9,106 posts

151 months

Monday 24th April 2017
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As above it can only be seen from underneath & if in the early stages can only be seen when the subframe is at least partially dropped.

helix402

7,832 posts

181 months

Monday 24th April 2017
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Great cars, as others have said you can only check for floor cracks from underneath.
I have just repaired a rear suspension mount crack on my touring:




bmwmike

6,918 posts

107 months

Monday 24th April 2017
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Great cars agree but I do wonder about all these cracks (boot floor, inner front wing) and bulges (front strut tower mushroom) and whether other marque's of the era had similar problems. Honestly I loved my e46, had it for 6 years, would love another but the body "weakness" puts me off as they are aging.

mark.c

1,090 posts

179 months

Monday 24th April 2017
quotequote all
MajorMantra said:
Seen that, but it doesn't answer my question. Clearly you can check underneath, but I'd like to know if one can learn anything useful without a ramp. I'm not convinced a small dealer will let me get that up close and personal with the car's underside...
It does answer your question. But for clarity you will learn nothing meaningful from inside the car.

You would however be able to conduct a degree of inspection with the car on a suitable trolley jack to give you some confidence prior to purchase.

If a small dealer wont let you do that or at least let you have it put on a ramp then you might want to think twice anyway.

GregorFuk

563 posts

199 months

Monday 24th April 2017
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You'll not learn much withough getting the car on a ramp but from my own experience I'd say one thing you could do is reverse diagonally up onto a steep incline (say a driveway or something similar). If the axel carrier panel is cracked then you will likely hear cracks and creeks as the chassis is twisted by the gradient change. Of course it could be down to other things going on with the suspension but it's a good indicator.

bmwmike

6,918 posts

107 months

Monday 24th April 2017
quotequote all
Mobile phone on a stick, if you can't get underneath?

Hairline cracks may be very difficult to see even if you can get it up on ramp. I bought my 99 in 2008 and even though I couldn't see anything wrong I put it into BMW to check. They found a 25mm crack and got BMW to approve replacing the boot floor. Looked fine to me!

git-r

969 posts

198 months

Monday 24th April 2017
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I had an E46 M3 with this issue.

The BMW dealer that fixed it said that every M3 has this problem and that (as has already been said) the only way to check is by removing the subframe.

I doubt the small cracks will give issue though as I've never heard of one failing, I'm sure there would be many stories of this happening if one did.

Funk

26,254 posts

208 months

Monday 24th April 2017
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I thought this was really only an issue on the M3 due to the power/torque? Does the 330 really have enough output to cause this?

MajorMantra

Original Poster:

1,265 posts

111 months

Monday 24th April 2017
quotequote all
Funk said:
I thought this was really only an issue on the M3 due to the power/torque? Does the 330 really have enough output to cause this?
If you google for it there are reports of it on most E46s, but it seems to affect the higher-powered models more. As usual with such problems, it's very hard to get a sense of high prevalent they really are. A bit like IMS failures on Porsches...

Thanks for the replies, all useful. I'm seeing the car tomorrow. If I like it I might just roll the dice.


fatboy b

9,492 posts

215 months

Tuesday 25th April 2017
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My 328ci had the rear nearside subframe bolt being pulled out of the body with 3 or 4 tears in the metal from the mounting hole. I had a creaking noise inside for a few weeks before hand thinking it was rear seats creaking.

kev b

2,708 posts

165 months

Tuesday 25th April 2017
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A few years back 328Ci developed these splits, I first noticed a slight cracking noise when manoevering, quickly becoming worse.

After inspection, one of the mounting areas was badly star cracked and the others were starting to go.

I don't drive it like I stole it either but I believe that having the traction control kick in a lot when trying to drive up my sloping driveway in ice and snow hastened the deterioration.

Five years later the repair is sound, I fixed it myself, without a lift, the hardest part was removing the manifold nuts.

This cracking seems to be a lot more common than people think, most mot testers do not check this area well as it is not a problem with other vehicles.

MajorMantra

Original Poster:

1,265 posts

111 months

Tuesday 25th April 2017
quotequote all
Well, I had an appointment to view the car this evening. I sent a text to confirm we were still on and politely asked if I could get under the car with a jack. Apparently that wasn't a reasonable request as he's told me not to bother now. A lucky escape, perhaps?

optimate

109 posts

83 months

Wednesday 26th April 2017
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if you really want to keep car and you can weld there are diy kits you can weld in

it aint a cheap fix to do it properly

or you looking at 1300-1440 for it done right somewhere properly with a kit it is very common
on E46

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




Edited by optimate on Wednesday 26th April 00:53

HugoFastmann

279 posts

117 months

Wednesday 26th April 2017
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MajorMantra said:
Well, I had an appointment to view the car this evening. I sent a text to confirm we were still on and politely asked if I could get under the car with a jack. Apparently that wasn't a reasonable request as he's told me not to bother now. A lucky escape, perhaps?
Sounds like it! Or maybe he thinks you're one of those dodgy buggers who "fixes" a car viewing to get money off, like the dirty oil thing I've heard about people doing...

MajorMantra

Original Poster:

1,265 posts

111 months

Wednesday 26th April 2017
quotequote all
HugoFastmann said:
Sounds like it! Or maybe he thinks you're one of those dodgy buggers who "fixes" a car viewing to get money off, like the dirty oil thing I've heard about people doing...
Maybe. The sudden change in tone was a bit weird, and he'd previously sounded normal enough on the phone.

The search goes on... Buying petrol estates is bloody hard work!

HugoFastmann

279 posts

117 months

Wednesday 26th April 2017
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MajorMantra said:
Maybe. The sudden change in tone was a bit weird, and he'd previously sounded normal enough on the phone.

The search goes on... Buying petrol estates is bloody hard work!
Good luck with your search! I spent 6 months tracking down my perfect E46...