[DementedF10]

Hello and I want to say I am new to this platform but not new to cars or boosted ones at all! I recently picked up a 2012 535ix. It runs amazingly well for 138,000mi and has had plenty of maintenance through its now 10 years. Car is mostly stock for now besides a MST intake and straight through exhaust. Car is also running a MHD stage 1 tune and XHD stage 2 I believe. The charge pipe is a factory replacement ( not sure why he did that but whatever)

My issue is that I am noticing a feeling like hesitation or almost like a miss when im hard on the throttle and in boost. normal driving is 100% fine. There are no codes per bimmerlink. Im wondering if this is a sign of fueling issue or possibly a leaking BOV etc. Is there any good way I can monitor or make use of bimmerlink to see what is going on? or any thoughts?

[ezaircon4jc]

No BOV. Unused boost is rerouted into the intake.

[95blkmax]

Not through bimmerlink that I know of (note that bimmerlink is supposed to be able to datalog but I personally have never seen a log generated by bimmerlink, so I can't vouch on how good/ if they're any good).

I'm assuming the last owner told you it had a S1 MHD tune but didn't give you the email linked to the VIN right? So in reality we don't ultimately know what tune if any is on the car at all? You'll have to buy MHD full suite so you can flash your own tunes first of all, but also use the monitoring feature. This allows you to record logs- which is what I would want to see to get an idea of the health of your engine. This would give a good direction as to any issues going on. Like if you have a boost leak, if you have a turbo that's not spooling well, if your fuel trims are out of wack indicating fueling issues, etc...

[DementedF10]

Since I originally posted this I have bought the MHD super license as well as Xhd license. I flashed the stage1 tune so I know exactly where it is now. Mainly because I desperately wanted to chill out the burbles. Was way too aggressive and annoyinh af! I also messed with the Xhd and currently am on stage 3 tune and wow I love how it shifts. I’m still feeling some odd hesitation at WOT but I think before I start trying to diagnose it any further, I’m going to knock out some basic maintenance items so I know I’m starting off with a fresh slate, like plugs, maybe coils pending what they look like, trans fluid and pan/filter etc. Thanks for the replies and Ill see where I’m at once I get more done.

[Dtex535]

Originally Posted by DementedF10

Since I originally posted this I have bought the MHD super license as well as Xhd license. I flashed the stage1 tune so I know exactly where it is now. Mainly because I desperately wanted to chill out the burbles. Was way too aggressive and annoyinh af! I also messed with the Xhd and currently am on stage 3 tune and wow I love how it shifts. I’m still feeling some odd hesitation at WOT but I think before I start trying to diagnose it any further, I’m going to knock out some basic maintenance items so I know I’m starting off with a fresh slate, like plugs, maybe coils pending what they look like, trans fluid and pan/filter etc. Thanks for the replies and Ill see where I’m at once I get more done.

Having the same problem after installing my mst intake, Ftp boost pipe/intake pipe and Gplus intercooler… fine under normal driving but if I get on it I get that hesitation/break up… never happened before. Did you ever figure out what was wrong?

[DementedF10]

So yes I did end up figuring out my issue. It was 100% unrelated to anything engine wise. I was convinced it was a miss or something engine related but it ended up being the transfercase clutches for the xdrive. I bought the Xdelete license to mess around with it and once it was in RWD only the issue was 100% gone! When you go back to AWD it does a clutch recalibration which solved the issue when back in AWD mode