[robplumm]

2010 335d, deleted, malone stage 2...

Recently changed out vac lines to silicone...MAF....and MAP sensors...

Was getting code for the MAP and there were leaks in the line leading to.the vacuum box, so decided to switch all since they never have been and car is right at 100k.

Since then, car is 1. Bit slower at take off and 2. Has a weird drop in power on gear shifts. It doesn't last long, but is noticeable. Almost like boost stops and kicks in again.

I've checked over the lines a few times to see if any splices were undone...all have good connections. Dropped old MAF back in to see if it made a difference...nada.

Looking for any ideas on what else to look for...

Have ProTool if there's any numbers to pull. Have reset adaptions on engine and tranny...

[Yozh]

Any codes?

[robplumm]

Originally Posted by Yozh

Any codes?

Just the AUC sensor...

[Yozh]

Have you reached out to your tuner for suggestions? You referenced that before the repairs your car was fine. You need to go over your work again to assure you have done everything correctly.

[Shmee]

Might be something to do with the tranny torque limiting it. Not sure why it would but the symptoms match up

[robplumm]

Originally Posted by Shmee

Might be something to do with the tranny torque limiting it. Not sure why it would but the symptoms match up

Almost what I'm thinking. Only seems to do it as it switches at about 60 when on the throttle heavy. Lighter throttle it doesn't seem to do it...thinking due to lower/slower torque build.

Thinking maybe TC slip bc of that.

Had thought about doing an xHP tranny flash anyway...may toss that at it and see. One of the things it seems to do is add pressure to the TC to deal with the extra torque of the tune.

[335dlci]

I tbink your 2 is related to 1 which occurred when you did the vacuum lines. This can cause weird transmission shifts.

[robplumm]

Originally Posted by 335dlci

I tbink your 2 is related to 1 which occurred when you did the vacuum lines. This can cause weird transmission shifts.

Apparently so. Looks like red line issue. Not sure if bit I left in (didn't take box off, cut and spliced into red line under it....so maybe 4-5in of original line left) or solenoid it plugs into. But red line doesn't hold vac and blowing some smoke into the line it pours out the back end of the vac box.

Aside...protools shows it's asking for 44psi at a nudge over 3k rpm. It's dropping from 36 to about 20 at that shift point.

Malone says that's way high obviously....should be asking for no more than 35-36.

Makes me wonder if it WAS sending that much and blew something out....

Will be remapping as well (they've updated the tune since I got it done in 2016...)

[335dlci]

Sounds like you have mixed up a line or two

[robplumm]

Originally Posted by 335dlci

Sounds like you have mixed up a line or two

Close...

So...I had gone over everything I could.

Finally took it to local shop (not one that did tune originally...other one I use)

They were baffled.

Vacuum held. No leaks. So confirmed what I knew there.

Deeper dive...many hours later...waste gate to small turbo staying open. Ok..that explains the drop at 3000rpm. Both waste gates open at that point...so pressure drops...until it can build back up in the now larger "container"

So...they reversed the lines on vacuum. And waste gates operated correctly
...just...now all power was on high end...which was an issue I had before.

Basically when I changed out the vac lines, I put.them on correctly whereas before they weren't.

Soooo....best we can surmise is that when tune was originally done, the vac lines were put on incorrectly and the tune adjusted to equate for what they were seeing. It never felt quite right, and was wife's car at time...so honestly didn't worry too much about it...now we're divorced and the car is mine...so...old issues getting fixed correctly bc I'm actually driving it (she didn't know what she didn't know and it was still better than before the tune)

I have a flashzilla enroute and am going to pull the tune to send to Malone. So...see what happens there.

[Shmee]

Okay now that I'm understanding what's going on better I can maybe add another comment. When I was doing my vac lines on my car I had a similar issue with basically no low end boost, which seems to be your issue? Basically baby turbo was doing nothing. I had no idea what was going on but all I I did was hook up my Carly scanner and cleared some random codes that came up and bam, baby turbo was back online again. Makes no sense to me but idk thought I'd add that in. This was a while ago and all is well.