E46 M3 / 330 subframe/ floor pan.
E46 M3 / 330 subframe/ floor pan.
Author
Discussion

Tame Technician

Original Poster:

2,467 posts

235 months

Sunday 17th July 2011
quotequote all
Does any body know when / if they ever actually uprated the floor pan where the rear subframe attaches. Have been told different things from different people.

One mate of mine is looking at E46 M3's to buy, and I'm looking at 330CI (slightly different budgets)

Have looked under a number of cars and with the subframes fitted its virtually imposible to see if the floor has cracked or not.

Just wondered if there was a factory modification or production change that could rule out all the fear of buying something that could turn out to be a complete nightmare.

Also if you get a Vanos failurem does it put the valve timing out enought to destroy the valve train, or does the Vanos assembly just need repairing/ replacing.

Thanks in advance.

TT
(Audi dealer master tech)

With subframe and underseel removed


muckymotor

2,499 posts

252 months

Sunday 17th July 2011
quotequote all
I can't help you I'm afraid but I'm staggered BMW didn't sort this when the e30 started to tear its boot floor out.

I've had a similar problem with my m coupe although it's now repaired and stronger than when it left the factory.

Pig Skill

1,368 posts

234 months

Monday 18th July 2011
quotequote all
Ive researched this subject and firstly it's not a very common occurrence — you just hear about the ones that fail. Secondly I believe that BMW carried out a few goodwill repairs via foam injection for minor cracking and floor replacement on more severe cases. I believe BMW did not carry out any modifications on the later models as the occurrence was so small.


http://www.simracing.no/e46fanatics/Dag65/e46_subf...

Sir_Dave

1,506 posts

241 months

Monday 18th July 2011
quotequote all
BMW will repair for free if the car is under 10 years old & non-modified.

From what i can gather, without getting the car up in the air & giving it a good clean, it is very difficult to tell if the subframe is cracked. Although there is quite often a tell-tale 'clicking' from the rear of the car whilst driving.

My suggestion is to buy a car less than 10 years old & do the inspection/get it done by an Indy, then take a visit to your local BMW dealer for the remedial work, etc.

Carlton Banks

3,676 posts

267 months

Monday 18th July 2011
quotequote all
Sir_Dave said:
BMW will repair for free if the car is under 10 years old & non-modified.

From what i can gather, without getting the car up in the air & giving it a good clean, it is very difficult to tell if the subframe is cracked. Although there is quite often a tell-tale 'clicking' from the rear of the car whilst driving.

My suggestion is to buy a car less than 10 years old & do the inspection/get it done by an Indy, then take a visit to your local BMW dealer for the remedial work, etc.
Actually, I am sure this must be dealer specific as a good friend of mine with a heavily modified Z3M Coupe had his repair FOC by BMW as a goodwill gesture.


The Ferret

1,295 posts

191 months

Monday 18th July 2011
quotequote all
Pig Skill said:
Ive researched this subject and firstly it's not a very common occurrence — you just hear about the ones that fail. Secondly I believe that BMW carried out a few goodwill repairs via foam injection for minor cracking and floor replacement on more severe cases. I believe BMW did not carry out any modifications on the later models as the occurrence was so small.


http://www.simracing.no/e46fanatics/Dag65/e46_subf...
It's more common than most would think.

In answer to the OP, BMW did not modify any of the E46 subframes during production, failures have been reported on 06 cars.

However, if it's under 10 years old get it diagnosed by an Independent specialist then take their report to BMW and ask for the repair. Not heard of a single case refused so far, providing the car is not modified.

Carlton Banks

3,676 posts

267 months

Monday 18th July 2011
quotequote all
The Ferret said:
Pig Skill said:
Ive researched this subject and firstly it's not a very common occurrence — you just hear about the ones that fail. Secondly I believe that BMW carried out a few goodwill repairs via foam injection for minor cracking and floor replacement on more severe cases. I believe BMW did not carry out any modifications on the later models as the occurrence was so small.


http://www.simracing.no/e46fanatics/Dag65/e46_subf...
It's more common than most would think.

In answer to the OP, BMW did not modify any of the E46 subframes during production, failures have been reported on 06 cars.

However, if it's under 10 years old get it diagnosed by an Independent specialist then take their report to BMW and ask for the repair. Not heard of a single case refused so far, providing the car is not modified.
They have previously repaired modified cars.

My friend's Phoenix MCoupe has been fettled and had the dreaded bootfloor / subframe issue and BMW repaired it.

Tame Technician

Original Poster:

2,467 posts

235 months

Monday 18th July 2011
quotequote all
Thanks for the input chaps.

I guess checking them on inspection prior to purchase isnt going to work (too hard to see)

I'll just have to get it up on a ramp and drop the rear subframe/axle assembly a bit and see what I can see.

Off to BMW for a free fix if its cracked.