High Mileage Used 2012 135i DCT - Scared to Tune?

[hotchicken]

Hey all, this is my first BMW and first higher performance car. I am interested in doing some tuning starting with a JB4, but I am a little nervous given my high miles.

I am the 2nd owner. Bought 9 months ago with 87K miles. Now have 95K. No warranty of course. Prior records I could find indicated normal maintenance OK and nothing exceptional.

I have had the pleasure of replacing a failed water pump, expansion tank, and chargepipe (went with aftermarket CP). Also repaired the oil filter housing leak (including new drive belt). Did VANOS recall repair.

In terms of maintenance, I have changed oil, had transmission service done (filters and fluid), rear diff fluid changed, walnut blasting, and had software updated.

I know having the water pump fail is normal, as is all the other stuff I have had done. Still that has made me feel like the car is a bit touchy or delicate, and so I am nervous about adding power.

No driving/running issues. I do feel a bit of a "rumble" under acceleration at around 2000-2500RPM. Could just be exhaust sound that I am perceiving as vibration, but that is the only time the car is not 100% smooth. I seem to feel it in my right foot on the accelerator pedal if that makes any sense. I may just be being paranoid after $2000 in repairs and $2000 in other maintenance.

Am I being a wuss here, or should I be afraid of tuning this higher mileage car?

Thoughts appreciated.

[e92ben]

Just tune it!! Enjoy the car! Looks like you did some maintenance already! You'll be fine

[hotchicken]

Originally Posted by e92ben

Just tune it!! Enjoy the car! Looks like you did some maintenance already! You'll be fine

Have a JB4 on the way. Still scared, but we'll see. Thanks!

[pepper135I]

Originally Posted by hotchicken

Have a JB4 on the way. Still scared, but we'll see. Thanks!

At how many miles did your water pump go ?

[hotchicken]

~89k. I was on the interstate. I was out of love for a few weeks.

[pepper135I]

Originally Posted by hotchicken

~89k. I was on the interstate. I was out of love for a few weeks.

Nice sounds like your car was mostly used for highway miles if that was the original water pump!

[houtan]

Is your car flashable? With the jb4, I would keep a close on your DCT slipping. BMS says it should be fine on the stock turbo, but people have experienced slipping on the stock turbo. The transmission sees lower than actual values because if the jb4 so it doesn't know to increase the required pressure to the clutch pack. With the BEF, you can increase the values going to the transmission. Again, you should be fine on the stock turbo, but I would keep an eye on slippage.

What did they do to service your DCT? Drop the oil pan?

[hotchicken]

Originally Posted by houtan

Is your car flashable? With the jb4, I would keep a close on your DCT slipping. BMS says it should be fine on the stock turbo, but people have experienced slipping on the stock turbo. The transmission sees lower than actual values because if the jb4 so it doesn't know to increase the required pressure to the clutch pack. With the BEF, you can increase the values going to the transmission. Again, you should be fine on the stock turbo, but I would keep an eye on slippage.

What did they do to service your DCT? Drop the oil pan?

I will keep that in mind for sure. Have a JB4 on the way. Would not upgrade turbo unless maybe the stock one dies. I won't be hammering it all the time. Just want the extra for occasional kicks.

They dropped the pan and changed two filters as I understand it.

Thanks!

[feignaw]

I didn't see you mention ignition system maintenance so be prepared to do plugs and possibly coils depending on how the timing looks in your logs once tuned.

[hotchicken]

Tech says plugs look good. I'll watch closely though. Thanks!

[The Wind Breezes]

Tuning has little marginal effect on most cars maintenance wise. I've heard of the DCT slipping but that shouldn't happen unless you're running high power, maxed out early / midrange boost on the stock turbos. If you want to tune the car to have most of the speed and a more linear power band you can dial back the power where the main torque spike happens. I think JB4 includes the ability to do this yourself.

[acoustix]

When I first purchased my DCT I had a few similar issues as you (oil filter housing leak, charge pipe) also had a rear crank seal leak.

I now have a jb4 and I am also running Meth. I have never regretted tuning the car and in fact, I actually recommend it because it wakes up the beast inside
Of course I still recommend looking over the engine compartment and problematic locations that are known for the n55 every once and a while/monthly.

Also PPK flash should help with the clutch slipping if it's comes to be a problem. I would recommend Cobb too but the 2012(some are flashable) and up guys are out of luck.

[houtan]

Spark plug replacement interval is reduced if you are tuned. I think the recommended interval is every 25k miles if you are tuned. Stock I believe they last double the miles.

Originally Posted by The Wind Breezes

Tuning has little marginal effect on most cars maintenance wise. I've heard of the DCT slipping but that shouldn't happen unluckyess you're running high power, maxed out early / midrange boost on the stock turbos. If you want to tune the car to have most of the speed and a more linear power band you can dial back the power where the main torque spike happens. I think JB4 includes the ability to do this yourself.

[hotchicken]

Good stuff. Mine will take a Cobb per their customer service.

[barnsdale]

I'm in the same situation - starting to rack up the KM's and I think the first thing I'm going to do is change the suspension, I honestly couldn't imagine adding more HP with the stock M sport suspension

[mike@x-ph.com]

My car is 120k miles pushing more than 20 psi ... Tune it, and enjoy

[hotchicken]

Originally Posted by mike@x-ph.com

My car is 120k miles pushing more than 20 psi ... Tune it, and enjoy

Yes!

[hotchicken]

Added BMS intake this week and JB4 last night. We'll see!

[hotchicken]

Installed the tune this weekend. Honestly kind of spooks me. Feels like I'm floating when I go WOT. Maybe a tire or suspension thing. Just feel disconnected from the road.

[ExigeS]

Originally Posted by hotchicken

Installed the tune this weekend. Honestly kind of spooks me. Feels like I'm floating when I go WOT. Maybe a tire or suspension thing. Just feel disconnected from the road.

I've read that replacing the rear subframe bushing with the M3 ones makes a massive difference here. I'm planning on doing that at some point as well.

[canadarob]

Use Whiteline KDT917 Subframe Bushings to fix your float problem. Cheaper than M3 bushings and much easier to install!

[houtan]

Originally Posted by canadarob

Use Whiteline KDT917 Subframe Bushings to fix your float problem. Cheaper than M3 bushings and much easier to install!

+1

Rent the tool from hpa, extremely convenient and makes removal very easy.