For New Owners - What I wish I knew when I first bought my E9X M3:

[pbinmich]

Originally Posted by Assimilator1

The latter cars (2010 ish) which have the alu/tin/copper bearings seem to fare better than the earlier ones. When pulled, they certainly still come out with some wear on them, but I haven't yet seen any of those which have worn through the babbitt (protective) layer to the copper. But they still have abnormal wear compared to most other engines out there.
You can look through several hundred photos of bearing sets pulled yourself if you like! , like I did! Lol, see here - https://www.m3post.com/forums/showthread.php?t=1253084 , or you could look at my summary I did a few years ago (link in my sig).
Oh and there is still some debate as whether mild detonation at least could be contributing to the bearing problem, but who knows!?

With the earlier bearings it's clear cut, just ditch them because it's pretty much a case of when they fail, not if (for ~98% of them anyway).
The later ones it's not so clear cut, I'd say the risk is lower with them, but failures have occurred. Personally I would change them for piece of mind at least.

Original throttle actuators will fail sooner or later too, but with those you could just leave them until they fail, it won't hurt your engine (it'll just run poorly), although it could be a right pain in the neck if one fails on a long journey!

Welcome to the club btw , got any pics of your M3?

Thanks. Here's one...I've since cleared the headlight mist, washed, clay bar cleaned, buffed, and waxed - looks great

[Assimilator1]

Very nice
Interlagos blue? That's one of my favourite colours!

[pbinmich]

I do believe that is the color name...it is nice. Initially, I was just looking for a 4-seat hard-top convertible with a descent engine - there's few options. That this used car popped up, also being an M3, last year with a V8, in a cool color, 45k miles...I'm very happy - found at a HONDA dealer no less.

[Weather Man]

So, since I am thinking of picking up a M-3 V-8 powered auto-trans Coupe, I read through the thread and found the following biggies to look for. Any obvious ones I missed?

AC compressor

Motor mounts

Rod bearings

Buy 2009 or newer

DCT weeping

Auto trans service Pressure filter, suction filter, and a suction jet pump

Gas cap rubber fails to seal

Replace spark plugs often

The E9X M3's two throttle actuators will eventually fail. Replace proactively?

[Assimilator1]

Personally I'd leave the throttle actuators until they failed as it won't harm the engine.
Unless you often go on long journeys, in which case it would be more inconvenient.

Btw, curious as to why you mention buying from 2009 onwards?

[Weather Man]

Originally Posted by Assimilator1

Personally I'd leave the throttle actuators until they failed as it won't harm the engine.
Unless you often go on long journeys often, in which case it would be more inconvenient.

Btw, curious as to why you mention buying from 2009 onwards?

Seemed to be enough improvements in engine and transmission reliability in the posts to steer that way.

[Richbot]

Originally Posted by Weather Man

So, since I am thinking of picking up a M-3 V-8 powered auto-trans Coupe, I read through the thread and found the following biggies to look for. Any obvious ones I missed?

Missed:

Recalls - fan blower wiring, possibly battery disconnect module, and airbag, get done if not done

Valve cover gaskets

Engine grounds

Comments:

AC compressor - No, what?

Motor mounts - Yes

Rod bearings - Yes

Buy 2009 or newer - No (unless you want idrive, then yes, but you shouldn't, because screens are for doors). There is zero functional difference mechanically. 2008's are older and were made in larger numbers than most of the other model years, so you'll see more issues popping up with them. I'll go one further and say unless you are keeping it completely stock and really want ZCP (which is 2011+), 2008's are a much better value on the used market than anything newer again because age and scarcity both weigh in favor of a lower price on the 2008's

DCT weeping - Yes (but get a manual)

Auto trans service Pressure filter, suction filter, and a suction jet pump - Yes but get a manual)

Gas cap rubber fails to seal - Yes, I suppose, replace it when you need to get to free shipping at the parts shop

Replace spark plugs often - Yes, halve the factory time (I do mine about every 15,000 miles). Also consider doing coils proactively

The E9X M3's two throttle actuators will eventually fail. Replace proactively? - No. You'll have warning. They start throwing codes that don't immobilize the car. Order some then

[Assimilator1]

Originally Posted by Richbot

Missed:
.....

Replace spark plugs often - Yes, halve the factory time. Also consider doing coils proactively

.....

Any good data on that?
I saw Evolve did a good video on that, showing dyno before and after figures with new plugs, which had done 30-40k miles.

Change the coils proactively!? Have you seen how much these are!?
(IIRC ~£100/coil).

[Richbot]

Depends on age and mileage obviously. The coils in my car were about 8 years old and 80,000 miles old when I changed them, and I'm at 142,000 miles and 16 years old now. Mostly for me it was about servicability - the old coils were getting brittle and stiff. They get hot, and are plastic, and you have to yank hard on them to get them on and off. You can always keep the old ones as spares or rotate a couple newer ones to the back of the engine bay.

I noticed a pretty big difference in part throttle/transient response on new plugs after the plugs get above 20k miles back when I let that happen, so I stopped letting that happen, and I no longer notice a difference changing at 15k. The dyno doesn't tell you everything. It's also a good excuse to check for oil leaks on the valve cover with stuff out of the way

I'm one of the ever-diminishing number of people on here who have owned their car since it was new. Please be kind to me in my old age.

[Assimilator1]

Richbot
Wow! Impressive you're the original owner!
I wonder how many there are of you here?

Re plastic, yea good point, mine's a 2008 year car (81k miles) and I broke a chunk of plastic getting one of the coils out! Had to seal the gap with silicone sealant, lol. Still works ok though.
Next time I pull them though I'm going use a cord and a lever to remove them, hopefully spreading the load will prevent any more damage!

Re plugs, interesting, my plugs have done about 20k miles, and I've noticed it somewhat flutters/splutters on giving it a small to modest blip of throttle from idle when stone cold to 'luke warm'. I've also noticed it getting a bit worse over the past couple of k miles or so (low annual mileage).
Perhaps my plugs are starting to go 'off'......
[edit, it's not the slightly damaged coil as it doesn't seem to be affecting just 1 cylinder and also it didn't happen immediately after the coil damage, and it's fine from warm to fully warmed up/hot).

[Fredkayaker]

I just bought my 1st M3 and have found this particular post to be very helpful. Thanks for posting it!

[mainuser]

Food for thought, great thread and discussions therein, especially those last few posts. Hopefully an owner in the not too distant future.

[Herofmine]

My suggestion is to not put all the focus on whether the car has an original owner or not. I’ve seen cars with single owner as well as multiple that have been badly neglected and not taken care of well, even though they have a clean Carfax report.

Having an original owner and a clean Carfax report doesn’t guarantee that you’ll get a clean car.

For example, I have a three-owner M3. I didn’t care how many owners it had or what the Carfax report said. I actually went and inspected the car myself. I went through everything from the undercarriage to the paint condition.

To make sure:

- The car has original paint.
- The undercarriage is clean.
- The engine bay is clean.
- The open engine cap is checked to see how things look.
- The car is tested driven to listen to how the engine and transmission sound, as well as how the manual or DCT shifts.
- The axles and drive shaft are checked for any noise.
- The engine oil change intervals are checked.

A combination of these things will help you get a “perfect” car for you, depending on what you’re looking for and your budget.

I’m currently on my second E92, and both have been amazing so far.

[Edwardsc1]

Originally Posted by Herofmine

My suggestion is to not put all the focus on whether the car has an original owner or not. I’ve seen cars with single owner as well as multiple that have been badly neglected and not taken care of well, even though they have a clean Carfax report.

Having an original owner and a clean Carfax report doesn’t guarantee that you’ll get a clean car.

For example, I have a three-owner M3. I didn’t care how many owners it had or what the Carfax report said. I actually went and inspected the car myself. I went through everything from the undercarriage to the paint condition.

To make sure:

- The car has original paint.
- The undercarriage is clean.
- The engine bay is clean.
- The open engine cap is checked to see how things look.
- The car is tested driven to listen to how the engine and transmission sound, as well as how the manual or DCT shifts.
- The axles and drive shaft are checked for any noise.
- The engine oil change intervals are checked.

A combination of these things will help you get a “perfect” car for you, depending on what you’re looking for and your budget.

I’m currently on my second E92, and both have been amazing so far.

This right here is really the only correct way to do it. On something as high performance as an M3, it all comes down to how the car was maintained. A clean CarFax doesn't mean a thing if the car hasn't been regularly serviced. Just the same as a one owner car doesn't mean that it wasn't redlined when the engine was cold. I say you always, always have to do your research and go see a car in person before purchasing.

[mycars]

New to the community and starting my research for an E90 6MT (ideally ZCP) to buy in MAR-APR 2026. Thanks for the great thread!

[info@epm.com]

I hope first-time owners can find this thread! Very informative. Thank you for helping out the community!

[ATL_Flat6]

Just purchased my E90 and am very grateful for this thread. Thank you!

[DrFerry]

For any new owner of an E9X M3 this FCP Euro video is well worth the investment in time to watch. You will learn everything (pretty much) you need to know about the S65 engine maintenance and nearly all of its ancillaries.
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