I just got a bone stock 2012 135i - advice wanted on my upgrade and maintenance plan

[Kootenay135i]

I just bought a 2012 e82 135i with 45,000 miles on it. It has an almost-complete dealership service history. I test drove the car and immediately loved it. Once I got home, I started researching the car in detail and that led me to 1addicts.com. What I read convinced me to follow through and buy the car. In the 3 weeks since then, I have probably spent 50 hours on 1addicts learning so much about the car and how to improve and maintain it.

So first I want to say a huge thank you to everyone who has contributed to this knowledge base over the past decade. This forum is really high quality and it’s been invaluable to me.

The biggest pain point for me so far has been the DCT. I did read about the pros and cons of it before purchase, but I didn’t fully appreciate just how awful it is at low speeds. The AT in my 20-year old Dodge Dakota behaves better below 20mph. As with many people on this forum, it really bugged me. But thanks to 1addicts I have already made some improvements and have a plan for more.

I have a plan now to do all the initial maintenance, and also for some mild performance enhancements. Basically I’m trying to summarize what I have gathered from you all so far. I would love your feedback on my plan. Thanks in advance.

Initial maintenance @ 45,000 miles, new to me (except for tires and brakes)

1) Change oil (and every 8K miles, with Castrol Syntec European Formula SAE 0w-30 or similar. BMW says 10K miles using the BMW OEM oil but it’s super expensive)
2) Flush coolant - no record of it being changed (flush every 40K miles? BMW says only when coolant is cloudy? Is there a specific coolant standard I need to look for?)
3) Flush brake fluid - no record (every 35K miles approx).
4) Flush diff - no record (every 40K miles approx)
5) Leave spark plugs - new OEM plugs 10K miles ago (every 30-50K miles)
6) Replace coils - no record (every 50-80K miles, before adding more power)
7) Replace intake filter and cabin air filter
8) New AGM battery (same amp hours as existing 4 year old unit, need to code and register it)

DCT problems

This is what I have done so far with my DCT. I would say that all up i have reduces the problem by about 50%, but would love to do better.

1) reset various engine and trans adaptations, e.g. throttle, idle, MAF (perhaps needlessly?)
2) reflashed DME with MHD Stage 0 map
3) reflashed DCT with XHP Stage 3 map
4) bumped idle up by 200rpm to deal with rpm fluctuations due to A/C compressor

This is what I still plan to do:

1) Have indy mechanic update DME firmware to latest
2) Apply fixes from SIB 12-15-14
3) DCT fluid change? (BMW says DCT fluid is lifetime. Many 1addicts are skeptical and recommend a fluid and filter service in the 50-80K range. Should I consider this step? Any chance it will improve the shifting?)

Upgrades

I’d like to add 50-80 HP eventually to this car. It looks like I can do that with very few mods. Is this a sensible list?

1) Replace charge pipe - stock one is very weak and can’t take more boost
2) Larger FMIC - any recommendations?
3) MHD Stage 1+ (is the PPK better?)
4) No need for intake changes other than a reasonably clean and new stock filter
5) No need for exhaust changes for this kind of power. But I would love to hear my car more. The BMW Performance exhaust sounds the best to me. I can’t find one to buy anywhere. So instead I ordered a Supersprint resonator delete pipe and intend to do the DIY Performance exhaust mod that 1addicts seem to like (welding some of the holes shut inside the stock muffler).

[iminhell1]

My opinion. Put the car through some paces before you do any upgrades. The cars have handling quirks and more power only makes them worse. Make sure you have a good grasp on how the car drives stock and the things you want to change to suit your driving style becomes very apparent.

[tracer bullet]

Your maintenance list looks solid. You could consider power steering and DCT fluids as well. I won't say you need them, just to round out your list of all options to think about.

Upgrade list looks pretty standard. MHD is the go-to these days. Subframe bushings are fairly common as well. If you do any spirited driving around corners you'll feel some tail waggle form them being soft. Tires, too, depending on what you have now.

Can't tell you about the DCT, sorry.

[NorthernDancer]

Originally Posted by iminhell1

My opinion. Put the car through some paces before you do any upgrades. The cars have handling quirks and more power only makes them worse. Make sure you have a good grasp on how the car drives stock and the things you want to change to suit your driving style becomes very apparent.

Follow what this gent said. Also learn how to really drive the car. That means driving schools [often called HPDE].
Get REALLY good tires and brakes.
Learn to do your own oil changes and brake fluid flushes.
Good Luck

[a4nut]

Good call in the XHP flash. I have the stage 2, and the whole reason I got it was due to the DCT surging at low speeds with the ac on. I've had it flashed for about a year, and he not done any resets like you have, but I have experienced no surfing this summer in my daily commute. I can't tell you what's different, but maybe just that I've recently decided I like the mode of driving there the lever is to the left, but the sport button is not depressed. I've been driving like that for a few months as I like the shift points, so maybe it has learned a smoother style…but now that I've typed that, I'm sure it will come back today.

My 2 favorite mods are the suspension upgrades and the dinan stage 2. Makes a world of difference in my opinion.

Great car, and enjoy it!

[mfindigital]

My DCT had issues too, all resolved with my MHD Stg 1 flash years ago.

These cars aren't down on power, they have plenty. The issue for some drivers (like myself) is that our pathetic little stock turbo loses a TON of power over 5k RPM. When I dyno'd (on terrible 91 CAN) with my Stage 2+ tune with catless DP, I made about 320whp at 5100 RPM. That number drops DRAMATICALLY after that, bottoming out at about 250whp at 6750 rpm or so.

So as a fun, zip around town car, the low end torque is tough to beat. If you like to wind it out, at least go with a Pure Stage 1 turbo, though Stage 2 is much better. You don't build any power after 5100rpm with the PS2, but you also don't lose any.

[Kootenay135i]

Thanks so much for your helpful replies everyone

[zx10guy]

I just had to have all the adaptations reset on my car due to the DCT issues. Car drives as it should again. I had it done a while ago which fixed the problem for about 3 years. I then had it come back and had a mechanic friend attempt to do the reset with mixed results. Since my dealer was able to get a longer lasting fix done on my car I went back to them recently. Spent $169 for them to do it which I'm sure many of you all will say I spent too much. Don't care. I don't have the equipment handy and I don't want to be going shop to shop trying to figure out who can get this done properly for me.

So I'm interested in those that have done the XHP flash on whether this will truly fix this issue. I don't drive my car that much now as I have a daily beater. So I suspect I won't have to revisit this issue for much longer than 3 years.

As to the oil change intervals, I'm moving to every 5k miles. Makes it simple to keep the math straight in my head on when an oil change is needed.

I did a partial DCT fluid change. Only had the oil drained out of the pain instead of dropping the trans pan. Because I didn't have the trans pan dropped, I didn't replace the internal oil filter in the trans. The only filter that was changed was the filter on the side which is accessible directly. The only catch is the trans had to be dropped a little to gain clearance to get the filter in and out. This was done a bit after 80k miles.

I would also add to your list to check the serpentine belt. Maybe just replace it even if it doesn't look worn. There is an off chance that if the belt breaks due to age in your case, it can get wrapped around the crank and get sucked past the front main seal. Depending on when you realize this has happened will determine if you are looking at just dropping the oil pan to get the belt bits out or a whole new engine. In my opinion, it's not worth the gamble. And you might as well replace the tensioner and idler pulleys at the same time. I did this work and it's not that bad. Made easier if you have some specific tools. I was able to get mine done without having to remove the radiator fan.

[Aceway]

Originally Posted by a4nut

Good call in the XHP flash. I have the stage 2, and the whole reason I got it was due to the DCT surging at low speeds with the ac on. I've had it flashed for about a year, and he not done any resets like you have, but I have experienced no surfing this summer in my daily commute. I can't tell you what's different, but maybe just that I've recently decided I like the mode of driving there the lever is to the left, but the sport button is not depressed. I've been driving like that for a few months as I like the shift points, so maybe it has learned a smoother style…but now that I've typed that, I'm sure it will come back today.

My 2 favorite mods are the suspension upgrades and the dinan stage 2. Makes a world of difference in my opinion.

Great car, and enjoy it!

So XHP fixes the strange DCT behavior with AC on?

[Kootenay135i]

Quick update. First visit with the euro specialist indy mechanic. Turns out there's a couple of quite inaccessible and urgent transmission leaks. He thinks the root cause of my DCT problems are due to either low DCT fluid level or to the 10 year old DCT fluid.

"Both side and bottom Transmission pans are leaking. Upper electrical connector is leaking as well - Transmission has to come out to do repairs."

So first fix the leaks, then filter and fluid service on the DCT, then they will update the DME and transmissions s/w to the latest and reset the adaptations. They have to get parts in so it's going to be another 2 weeks until I know if this fixes resolve the issue.

This one is going to be spendy...

[zx10guy]

What your shop reported is pretty common with these DCTs from what I've seen around here. The top leak is probably with the mechatronics. From what I recall, the bottom pan is plastic and tends to leak due to it being well...plastic (warpage...heat cycling...age).

[Samuel Wikerson]

I have the exact same car, and I'd advise you to forget any improvements. The car will let you know what needs attention. For example, the car will eventually go into limp mode, and you'll discover you'll need a water pump and of course new coolant. No sense doing a coolant flush now, LOL!

What I'd advise you to do is keep an eye on the oil filter housing gasket. If it starts leaking and you don't fix it, it can lead to a catastrophic problem that'll destroy the engine, the accessory belt sucked into the engine. The next item is to change the oil and filter at least once a year or every 10K miles. Also keep an eye on the condition of the accessory belt and pulleys. I wouldn't let them go over 60K miles.

I have had a lot of experience with the DCT. The first thing to do is pull off the cover and check for leaks, since they are common. Next, I'd plan on doing a service on it at 50K. I did a write up how to do it. Also, if you have stalling, odd noises, or surging issues, there is software update that'll fix it. Guess how I know?

Finally, I'd stay away from tunes, JB4s, or any hot rod "improvements". You'll need the money for the eventual and predictable repairs. At the moment, my car is at the independent for misfires on cylinders 1, 5, and 6. I had this problem before, and it turned out to be an injector. I suspect this time it might be a coil(s).

Oh, and forget the dealer. Start doing research to find a good independent. They aren't that easy to find.

[NorthernDancer]

Good indy garages are not that difficult to find. First of all, ask another BMW owner [who has an older car].
I also go to bmwcca.org>Chapter finder>website. Often they'll have a list of "Resources" or their newsletter with ads from trusted BMW indys.
For Chicago, I found:
1. 7th Gear Auto repair in Schaumburg
2. thewerkshop.com
3. northstarmotorspoets.com
4. Olsons Custom detailing

[Samuel Wikerson]

Chicago must be a lot different than my state. I called every independent in my area, and none of them wanted anything to do with the DCT.

My experience with auto repair shops is they'll always tell you they can fix it until you find they can't.

[fast1eddy]

What I'm going to say will likely be controversial but I'd put everything you can into maintenace and keep the engine stock. I've done a lot upgrades to my car, mostly suspension and they made the car better. The power mods didn't really enhance the car for the street. At least for me. The extra power just means I use less rpms.

[Samuel Wikerson]

Actually, I'll be glad to get rid of this car. Dumb repairs keep happening like the overflow coolant bottle sprung a leak! I was stuck for doing the repair at the dealer who had the part for an outrageous price.

The problems I've had with this ride never happened with any of my previous cars. And they aren't unusual either being experienced by many people on this forum. A lot of this stuff is due to poor engineering and sloppy quality control, and from what I've read, the problems only get worst as you move up in the models.

My bottom line is no more BMWs for me.

[dtla1]

Originally Posted by Samuel Wikerson

Actually, I'll be glad to get rid of this car. Dumb repairs keep happening like the overflow coolant bottle sprung a leak! I was stuck for doing the repair at the dealer who had the part for an outrageous price.

The problems I've had with this ride never happened with any of my previous cars. And they aren't unusual either being experienced by many people on this forum. A lot of this stuff is due to poor engineering and sloppy quality control, and from what I've read, the problems only get worst as you move up in the models.

My bottom line is no more BMWs for me.

I'll buy it for cheap, lesson the load on your worries.

BTW, which software update fixes your problems? DCT software issues always seem to be a crap shoot and doesn't really seem like 1 update/software change fixes all.

[Samuel Wikerson]

Well my misfires were due to one dead coil and two functioning intermittently. I had all 6 replaced. More dollars flying out of my wallet!

My independent does lots of BMW service. He is very grateful for the brand, since he receives a significant amount of revenue from repairs.

Ever hear of the Car Ninja? BMWs built his million dollar repair facility:

Notice the Ninja smiles a lot likely thinking about the size of the repair bills, LOL!

[fast1eddy]

If you're gonna own a BMW and want to keep repair bills down you need to DIY. I just put in new coils. Literally a 30 minute job with basic tools and knowledge. Didn't even pull my car into the garage.

[Samuel Wikerson]

Originally Posted by fast1eddy

If you're gonna own a BMW and want to keep repair bills down you need to DIY. I just put in new coils. Literally a 30 minute job with basic tools and knowledge. Didn't even pull my car into the garage.

I've done tons of repair work on cars over the year, and I know how to use diagnostic tools and interpret the results. However, I have an excellent independent who charges fair prices and does excellent work. He has also done work where I have supplied the parts saving me from difficult jobs I preferred not doing. For example, there have been some things that were difficult due to using jack stands that were relatively easy with a lift.

In any case, his labor rate is $118/hour which is a bargain in my area. Also, he has noticed things that needed attention that I completely overlooked. Another plus is he knows the best brand of parts for BMWs.

My point is an experienced tech will save you money in the long run especially when you are only concerned with maintenance and keeping your ride on the road. Of course, if you enjoy screwing around with cars and want to do "improvements", then the cheapest route is DIY.

[tracer bullet]

Originally Posted by Samuel Wikerson

Of course, if you enjoy screwing around with cars and want to do "improvements", then the cheapest route is DIY.

Agreed, but - if you've done tons of repair work over the years, it's a valid suggestion to have DIY'd the coils. It's basic tools, and the hardest part of the job is just being sure you don't forget to plug in all the connectors at the end. You are free to choose not to do it of course, but as a general idea for folks feeling slightly handy, this is one to go for.

[Samuel Wikerson]

Originally Posted by tracer bullet

Agreed, but - if you've done tons of repair work over the years, it's a valid suggestion to have DIY'd the coils. It's basic tools, and the hardest part of the job is just being sure you don't forget to plug in all the connectors at the end. You are free to choose not to do it of course, but as a general idea for folks feeling slightly handy, this is one to go for.

Well it's really hot around here, and I don't mind spending a couple of hundred dollars for labor. It just isn't a big deal.

Also, when I ran a scan, it only told me that cylinders 1, 5, & 6 were misfiring. Having had the same problem previously, cylinder misfires, it turned out to be injectors. That time is was done under warranty.

When I was younger I did everything from painting the house to rebuilding engines. I had too, since I didn't have any money. Also, I've never been too keen about getting my hands dirty, and my situation is entirely different today.