Buyers guide - E46 M3 (or CSL)

[M3_Power 636]

15/2/10 - SMG Info update

3/3/09 - Engine oil information update

24/04/09 - Updated rear subframe (first reported case of a CSL - extensive rear modificatoin and solid rear subframe mount - this case is more of an exception than the rule by the looks of things - the tear in the subframe was also quite minor compared to others I have seen)

Well a friend of mine from the UK wanted to buy an used one of these and asked me about it. I decided to do a small write up for him on what to look out for when buying one.

I've written it based on the 6 speed model (non SMG) and based on the UK specs (in terms of the CS model) - I will update this as I have time and include the SMG models and the CSL models.

Most are based on my experience of these cars for the past 8 or more years and various research and reading from the net and some first hand experiences. It is by no means comprehensive and I will need to edit it from time to time.

I thought it might be helpful to post this information up seeing that E46 M3s are starting to be very attractively priced.

Errors and Omissions excepted:

Models:

E46 M3 (2000 ~ 2006)

E46 M3 CSL (Jun - Dec 2003 only) The ultimate variant of this model

E46 M3 CS (a watered down version of the CSL 2005 ~2006)

Years to avoid: (in my opinion)

2000 ~ Aug 2003 production - Engine issues (big end bearing tolerance issue resulting in blown engines - worst affected year would be anything made in 2002. A full recall was done by BMW around the world on this, so should you be looking for a car in this age bracket, check with a main dealer that the big end bearing recall has been done)

Desirability and model year changes:

Whilst the CSL is the ultimate incarnation of the E46 M3, it isn't for everyone. It is a harsh car more suited to the track than the roads of Kensington. The alternative and perhaps a good compromise is the E46 M3 CS. This model has, in addition, to what you will find on an E46 M3:

- CSL brakes (345mm on the fronts vs 325mm - larger rear pistons)

- CSL suede steering wheel (very nice, but wears badly)

- M-Track mode as found on the CSL (awesome on the track)

- CSL steering rack 14.5:1 ratio (faster rack - absolutely brilliant)

- CSL styled wheels

- CSL exhaust system (except for the catalytic converter)

The 'facelift' model came in early 2003: The main differences were:

- LED tail lights (better looking and two stages depending on brake force applied);

- longer boot handle (some say uglier)

- Larger 16:9 navigation TV screen (if equipped)

- Slightly different suspension, but hardly noticeable to be honest

- more interior trim options (most came with the titanium trim)

- some minor accessories became standard equipment (nothing to celebrate about)

Issues:

Focusing on the 3 main areas - mechanical, electrical and chassis

I won't focus too much on usual wear and tear that you see on the inside of the car, as these should be obvious upon inspection.

MECHANICAL:

A. Engine big end bearing:

- Original issue came from a third party bearing supplier tooling the tolerances too low, causing oil starvation and premature wear.

- recall centered around new bearing sets and new oil pump.

- recalled cars have been fine provided it was done properly in the first place.

B. Rear differential:- Groaning noise when turning (when car is cold or first thing in the morning)

- Actually normal given the high ratio multi plate locking diff that these cars carry.

- There is a dealer SIB (service information bulletin) to correct this noise issue - involves a diff oil additive - majority of the cars will have had this done (but still prudent to check)

- can get quite annoying after a while.

C. Gearbox (6 speed manual):

- As with all gearboxes, if treated well, they will last the miles.

- Unit is made by Getreg (perhaps the best gearbox company out there), so it is a reasonably reliable gearbox, but higher mileage ones have known to wear synchromesh causing a grinding noise (usually 2nd and 3rd gear). New gearboxes are expensive.

- Life time fluid isn't really life time - best to have it changed every 2 years.

- Gearbox bracket bushes can wear if driven hard or car tracked often - When purchasing have these inspected as they are reasonably tricky to get to to replace.

D. Clutch and flywheel:

- Clutch wear depends on the driver. Being a self adjustable clutch kit you can't actually physically feel a difference through clutch engagement point (the self adjusting pressure plate supposedly keeps the engagement point the same throughout the clutch life - the clutch delay valve also hinders this feel in the pedal) - Best way to test this is to throw the car in 3rd gear, push down on the clutch, rev the engine to about 6500 - 7000rpm and drop the clutch and see if it slips (climbing revs without the incidental speed increase) or if you spin up the rear end and feel a thump in the drive train (clutch is good).

- There's a usual clonking sound when the clutch pedal is pushed down (especially when coming to a stop abruptly) - this is normal (although you really have to know what you are listening to as there are other abnormal rear end clunks on this car) - this noise is simply the drive train slack and does not affect the overall operation or longevity of the vehicle.

- There are some reported cases of flywheel issues, but not common (resultant humming sound) Personally I wouldn't really worry about this one - it's more an acoustic issue than mechanical (it's related to the dual mass flywheel)

E. Vanos System:

- the S54 engine vanos system is what's known as a high oil pressure system. Being dual vanos it operates on both the intake and exhaust side.

- The system is a lot more reliable than those found in the E36 M3

- If you hear rattling noise like marbles in a can coming from the vanos system on start up ... walk away

- Or if you hear similar sound as above with rising revs ... walk away.

- very expensive to repair if broken

ELECTRICAL:

A. Ignition Coil:

- these are known to fail - no particular cause really - just a wear and tear item.

- Check that all cylinders are firing correctly - if not, usually it's due to a bad coil.

- easy to DIY, but expensive part to purchase.

B. Window regulators:

- Expensive part

- Have been known to fail on occasions

- check that the windows go up and down smoothly and without odd noises from the motor.

C. Passenger side airbag sensor mat:

- Common part on the BMW to fail for some reason

- expensive part (some NZ$380)

- Airbag warning light comes on

- easy to DIY, but very annoying fix, because you have to take the car to the dealership to have it recoded.

D. Alternator and Battery

- These are known to go between 60 - 80k km ... especially the alternator.

- expensive part brand new from BMW ($1200 for the alternator)

- Batteries are about $250

E. Everything else electrical on this car:

- Being a modern BMW, nearly ever aspect of the car is electronically controlled, this will mean a trip to the dealer for them to hook it up onto a dealership service computer to clear error codes or to simply programming in new replacement parts before it will start to work.

- Luckily not a common occurrence

CHASSIS:

A. Springs and shocks:

- the rear springs are known to snap (attributable to weather condition and other factors - ie. salt on the roads)

- It is a warranty repair item, but do check for broken rear springs.

- You should hear a noticeable clunk noise when going over bumps and judder bars

- Shocks do wear out after about 70,000km (lack of damping or rebound characteristics - i.e. lack of control - M3s should drive like its on rails)

- Original shocks can be quite expensive - aftermarket alternatives makes much more sense when they wear out (popular upgrade also)

B. Rear Shock Mount:

- This is the rubber mount on the rear shock

- a very weak design in the car and is known to crack and break

- Take off the rear wheel to inspect (look up at the shock mount and look for cracks in the rubber)

- Usually require changing after 30,000km and shorter if car is tracked.

- If not attended to can lead to torn rear subframe mount and floor (see below)

C. Rear Trailing Arm bush (RTAB):

- common failure part - circa 50,000km

- can only be seen with car up on a hoist - usual cracks in the rubber

- this is a very important bush as it controls lateral movement in the suspension and twisting action from the rear chassis torque transfer

- if left unattended can lead to subframe mount and floor cracks (see below)

- Cheap part, although labour intensive to replace (I have a special tool for this, so not to worry)

- Common upgrade is polyurethane bushes (if the car came with these, all the better) - you will hear some creaking noise however with poly bushes

- to test if the RTAB is worn, you will notice the following:

- Wallowing rear end under acceleration and braking (i.e. the car moves from side to side under heavy acceleration in a rolling start)

- the car pulls to one side excessively when braking hard

- Knocking sound when turning (although this can be something else also)

- Generally speaking the rear end won't feel 'planted'

- test this on a flat straight surface

D. Front Control Arm bush:

- the front equivalent of the rear trailing arm (the bush is located on the aluminum front lower control arm (triangular shape))

- Inspection from under the car

- wears out like the RTAB

- Front end instability under heavy braking (pulls to one side or wallowing)

- Cheap part, but a pain in the ... to change

E. Rear Subframe Mounting Floor:

- Unfortunately the E46 chassis suffers from a similar catastrophic chassis failure like the E36s

- The rear subframe mounting floor can crack and be completely torn off if:

- the car has been abused excessively (wheel spins, drifting ect)

- Heavily tracked without constant monitoring of the rear bushes

- hard impact damage from pot holes

- worn RTAB, rear shock mount, and rear subframe bushes

- Lift up the boot floor carpet and look for stress cracks in the metal floor (look at the metal joints and sealed joints)

- Look under the car floor by the rear subframe mount points (there are 4) - the rear subframe is the big black metal bracket that the rear differential is bolted to (check the rear diff bushes also).

- The common points that tend to get torn first is (looking from the rear of the vehicle) left front and right rear - but check all 4 mounting points.

- You really need to have the car up on a hoist to check this

- Cars made after late 2003/early 2004 had a different rear subframe carrier floor mounted and are supposedly less likely to develop this failure.

- the only way to fix this is to disassemble the whole rear end, including taking out the fuel tank and lots of welding. There are re-enforcement kits out there - if you are buying a car with this re-enforcement kit already installed then all the better (provided it was done properly)

- Some cars don't actually have a noticeable knocking noise from the rear until the floor is completely torn off (so seeing is better than hearing for diagnostic)

- There is a BMW TIS information on this and allows for initial stress fracture repair using and injected structural form. Only works if the stress lines are less than 20mm either side of the mounting hole - anything larger and it's a full floor repair.

- [Edit 24/4/09] - THERE'S now been one CSL reported with the subframe tear (Steve Gill's car - he frequents the Nurburgring A LOT (lots of his videos on youtube) - it's a fully resprayed Alpine White CSL) - Few things that make this case unique however - this car runs SOLID rear subframe mounts rather than rubber bushes and it also runs Intrax full coilovers including the rear with really heavy spring rates (stock set up has separate springs and damper set up) - Given the extensive tracking of Steve's car and the solid rear modifications (no roll cage or bar) one can assume that this might be an exception - there fore the comment below would still stand in my opinion ------ No CSLs have been known to have this issue (as strange as it may sound, it is a fact - one would think that a torque induced stress failure would be more prevalent on a higher powered car with almost slick tyres, yet there have been no reported failures on CSLs - some have suggested that this may be a weight thing, given the CSLs are over a 100kg lighter; others propose that CSL owners are fanatics and maintain their cars to a lot higher standard, hence the lack of the failures)

So that's about all the MAJOR issues you need to know when looking for an E46 M3.

Don't be phased about buying one because one of the above could potentially go wrong - the reality is, it is a rare occurrence and good examples are aplenty if you take the time and effort to look for it.

There are a couple of things that I have not gone into, such as worn brakes, brake discs (warping - juddering under braking) - or accident damage repairs (which should be obvious).

ENGINE OIL .... THERE IS ONLY 1:

- There are mixed information out there about the engine oil for the S54B32, some say there's two approved oil out there, whilst others stand by the fact that there's only 1 approved BMW engine oil for this motor.

- THERE IS ONLY ONE APPROVED BMW ENGINE OIL FOR THIS MOTOR PERIOD!!

So where's the confusion coming from? - well put simply, different branding between different continents. And the initial information from BMW that Castrol RS 10W-60 was also an approved oil in the Training manual for the S54B32 - it no longer is and have not been since end of 2002 when engines started blowing up.

The ONLY Approved oil is: Castrol TWS 10W-60 (or the UK equivalent Castrol Edge 10W-60) - These two are the SAME OIL, just different branding between different continents.

Castrol Edge "Sport" 10w-60 IS NOT AN APPROVED OIL and not the same as the UK version of Castrol Edge 10w-60

Here's the spec for the TWS

TWS Motorsport 10-60

Relative density @ 20.0 deg C = 0.865

Viscosity at 40 deg C = 163.1

Viscosity at 100 deg C = 24.3

Viscosity Index = 181

Flash Point (closed) deg C = 198

Pour point deg C = -42

TBN = 8.1

Information on:

Castrol Edge in the UK

http://www.castrol.com/castrol/productdeta...ntentId=7027067

Castrol TWS data sheet

http://www.tds.castrol.com.au/pdf/4247_TWS...397_2006_09.pdf

In comparison to Castrol Edge "sport" data sheet (you'll notice quite a difference between the two)

http://www.tds.castrol.com.au/pdf/4398_EDG...0W60_200601.pdf

So remember to put the correct oil into your motor.

Oil spec

SMG Info:

I would do a write up on SMG, but to be honest I'd just be repeating this thread

http://www.m3forum.net/m3forum/showthread.php?t=231113

The above is the best source for all things SMG (bar the workshop manual and service tech information booklet).

There's a couple of things that can go wrong with the SMG, mainly eletrical (relays, sensors - there's multiple of them) and some hydraulic (the pump itself or the pressure accumulator) and the least mechanical (compression spring or synchronmesh).

All in all it is actually a fairly reliable system - the trouble is your generic OBD2 tools can't diagnose what is wrong with it. If any of you with a SMGII or SMGIII car wants a diagnostic on the Autoenginuity tool, hit me up - more than happy to hook it up and see what is wrong with it.

Edited February 14, 2010 by M3_Power

[E46-RAT 1]

Excellent post,thanks very much for this,made for good reading.

[Forrest 35]

+1 for awesome post, need more stuff like this on the forum. Cheers man

[Yuen 16]

Thanks for that, very comprehensive, I think this should be parked.

[bravo 35]

Not sure where this thread should go, but will sticky if I can think of the right forum for it to be in. Maintenance or want to buy maybe?

[Forrest 35]

Not sure where this thread should go, but will sticky if I can think of the right forum for it to be in. Maintenance or want to buy maybe?

I vote for want to buy

[martyyn 2]

Buyers guide Bravo in WTB gets my vote

[CamB 48]

Great write up! Lots of good info there. I recognise a couple of, err "features" of the E36 too.

Best way to test this is to throw the car in 3rd gear, push down on the clutch, rev the engine to about 6500 - 7000rpm and drop the clutch and see if it slips (climbing revs without the incidental speed increase) or if you spin up the rear end and feel a thump in the drive train (clutch is good).

Not sure I'd be doing that often - you'd wear out the clutch pretty quick!

[M3_Power 636]

Thanks for the feedback fellas ...

Have always intended for this to be helpful to those that are looking at getting into an E46 M3.

Mods, feel free to move it to where ever you think the topic will best fit.

CamB - I do believe that clutch testing procedure is written in the BMW SIB or TIS, can't remember which one, but it's there (perhaps not in exactly those words, but similar) - you don't really need to test it numerous times to find out if it's indeed slipping ... if it is, it'll show up on the first test.

Have just updated the post .. will continue to do so as I get time to write it up.

Have tried to refrain from putting in links ect .. just to try and keep it as neat and readable as possible. If any of you wanted more info on it, feel free to PM me and I'd happily send you the information or a link to it.

[E30 325i Rag-Top 2963]

Excellent stuff, thanks.

Anyone know if there are any E46 CS models in NZ? Were they sold here new, I've only heard of them before in the UK?

A rough price guide for the CS v CSL v Standard?

[hybrid 1044]

Nice write up fella! .. A lot of general e46 info in there, epspecially around the sub frame problem that might help some of these guys dumping them down so low think twice about thier 10-20k e46 purchase.

[bennz 3]

Would be great if we could have your advice for choosing an e90/e92 M3 as well

[John M3 6]

Excellent post! Thanks a lot

[hydrom6 0]

Excellent post sir, a great service to all who contemplate purchasing one of these BM icons