Anyone here a BMW tech with knowledge of SMG issues?

My vet has bought a POS 56 plate M3 Convertible with the dreaded SMG gearbox. It often selects neutral on coast down or when stopped, especially once warmed up, and only selects a gear after prolonged fiddling with the paddles or frequent key on and off. The gearbox fault light comes on at such times. When it does drive it's usually OK. My Bosch software diagnostics are not proving too helpful. Thanks. Why *DO* people buy this junk?

Whifbitz might be able to help, they have been doing a lot of work with BMW DCTs. Worth asking Paul anyway.

Might be useful. From what I gather, the most common cause of failure is a dead pump.

http://forum.e46fanatics.com/showthread.php?t=929327&page=2

https://burkhart-engineering.com/54160en

However, as a worst case scenario, converting these to manual isn't a terrible job, as the gearboxes are the same to all intents and purposes I did consider one of thezse boxes as a swap in my Supra, as the E46 adapters are readily available, and the later CSL gearbox management is supposed to make these boxes superb things to use.

Good find, thanks for that! I don't think he'll be into swapping to manual. I'll see how I get on with some more diagnostic, cheers!

Whifbitz might be able to help, they have been doing a lot of work with BMW DCTs. Worth asking Paul anyway.

Good idea, will do, cheers.

Why *DO* people buy this junk?

The M3's have a lot of weak points. Aside from the auto box, the VONOS system being troublesome but nothing quite as damning as the

Maybe this shift issue video could point to something to check,

Found a pal has bought the genuine factory software to diagnose these as he specialises in auto gerboxes and was turning away loads of them, he commented that he'd like everyone in the area to buy one so he could fix `em up and retire early. Can be anything from a bonnet closure switch or a simple high amps relay to £5K plus... Mickey mouse job from BMW...Thanks everyone, will post the fault for closure in due course.

The M3's have a lot of weak points. Aside from the auto box, the VONOS system being troublesome but nothing quite as damning as the

. BMW M3's, particularly the E46s offer up plenty of good reasons to stick to Jap reliability.

 

Maybe this shift issue video could point to something to check,

?

I disagree.

The E46 M3 is actually a damn reliable car. Especially for one that runs such a high specific output and asks for nothing more than routine servicing.

The points you've mentioned are the car's only real weak points.

I would ditch the SMG and stick a manual in.

I disagree.

 

The points you've mentioned are the car's only real weak points.

 

Sub frame cracking is common and being common its pretty damning on BMW engineers being able to stress factor design properly.

It's not ideal but it's not something I'd hold against the E46 or BMW, because all cars have problems. And considering the M3 has surprisingly few issues, it's not something that would really bother me. Especially since a lot for sale have already had the subframe professionally repaired.

Google any model of car and they all have issues..

Porsche have their IMS issue

Mazda have the Rotary engine

Mercedes W210s rotted like 80s Fiat's, etc

There are other BMW's which have far more crippling issues than the E46 subframe!

I remember the Corsa B also had stress fractures which would appear by the B pillars back in the day when I had a GSi.

Did a bit of googling and stumbled onto this video of an e46 M3, the flex/movement when driving looks terrifying.

Basically if it's German it's crap:p

SMG pumps are common failures on E46 M3's and cause all kinds of issues/errors.

My brother had one and so did a mate, both suffered from this.

Looking like it's the pump or pump motor. What a POS these things are. Plus it wouldn't pull the skin off a rice pudding and flexes and twists like hell, (hopefully 'cos it's a rag top, and they aren't all like that). Towing eye supplied with the car in the moulded boot lid holder is far too short to reach the threaded insert behind the M3 bumper, you need a none existent Torx screwdriver to get into the main fuse box under the bonnet, and Googling general reliability issues suggests it's definitely not a good buy for a bank robber.

Basically if it's German it's crap:p

Sounds reasonable. I have 3 with hardly any problems with any of them.

Granted, the M3 sub frame issue is a cracker though. Besides a new battery my Z4M has wanted for nothing and the 330 Ci has survived being ragged regularly. Merc is on a 16 plate and has not yet been back to the dealer after 21K miles.

H.

Sounds reasonable. I have 3 with hardly any problems with any of them.

 

Granted, the M3 sub frame issue is a cracker though. Besides a new battery my Z4M has wanted for nothing and the 330 Ci has survived being ragged regularly. Merc is on a 16 plate and has not yet been back to the dealer after 21K miles.

 

H.

regularly??? About as regular as getting piles

regularly??? About as regular as getting piles

I do get piles regularly though. Your point being?

She is out again tomorrow.

H.

bit off topic but my '10 plate M3 is DCT - the paddle mode is very responsive but the auto mode is horse poo - lags constantly and delays selecting gears

Did a bit of googling and stumbled onto this video of an e46 M3, the flex/movement when driving looks terrifying.

 

Holey moley.

Sounds reasonable. I have 3 with hardly any problems with any of them.

 

Granted, the M3 sub frame issue is a cracker though. Besides a new battery my Z4M has wanted for nothing and the 330 Ci has survived being ragged regularly. Merc is on a 16 plate and has not yet been back to the dealer after 21K miles.

 

H.

You must be a very lucky man! Are you Irish by any chance;)

You must be a very lucky man! Are you Irish by any chance;)

Nope.

330 Ci has just done 40 odd laps of Oulton Park today at full keg, without an issue. You won't find many perfect cars these days. Supra is the best build quality I have seen to be fair but you can't eat the same food everyday or life would get pretty boring. You must have the experience of the car first hand to give an honest appraisal.

The Z4M is as much fun as I have ever had in a car but that will also need to be changed at some point, just not now.

H.

Might be useful. From what I gather, the most common cause of failure is a dead pump.

 

http://forum.e46fanatics.com/showthread.php?t=929327&page=2

 

https://burkhart-engineering.com/54160en

 

However, as a worst case scenario, converting these to manual isn't a terrible job, as the gearboxes are the same to all intents and purposes I did consider one of thezse boxes as a swap in my Supra, as the E46 adapters are readily available, and the later CSL gearbox management is supposed to make these boxes superb things to use.

I have one of these boxes sat in my garage as I was originally going to convert it to manual and put it in the Supra. Converting to manual looks very straight forward.

Did a bit of googling and stumbled onto this video of an e46 M3, the flex/movement when driving looks terrifying.

 

That video is a bit like thrashing a supra with a blown turbo and videoing the smoke coming out the back! Just needs repairing. They are a good car IMO. (the manual ones, non cabriolet)

I said I'd post the issue. the hydraulic pump brush cover was full of brush dust and the pump was drawing a huge current. The 40 amp relay that controls it, when opened, had no contacts left and was high resistance, hence the pump was slow and intermittent. I cleaned out the brushes and commutator, checked brush length, and despite some commutator wear the segments looked serviceable, so reassembled it and fitted a new relay. It seems fine now, or as fine as these things probably ever are....