Sluggish Acceleration

john6000777 · 03-01-2021, 02:59 PM

Hey what’s up guys I was wondering if anyone could help me figure out what my problem is. I have a 2013 X5 35i tuned on MHD Stage 1.

Long story short: the car has its moments when it feels extremely sluggish with bad throttle response and my MPG goes down the drain. It almost feels like an "unofficial" limp mode because I don’t get any codes or engine light. Usually on a cold startup the car feels fine but as I drive I can almost feel when the unofficial limp mode kicks in. This has been going on for about the past month and I feel the symptoms have been getting worse. Now, I am almost always in the unofficial limp mode.

I decided to take two logs: one when the car feels normal and another when it’s sluggish. I’m not a pro at reading logs so the only thing I noticed is that my Boost target drops from peaking at 13.4lbs when normal to only ~10.3lbs when the unofficial limp mode kicks in.

Here is the log when the car is sluggish:
https://datazap.me/u/johnogandouconn...L0XOEbO4pAoZuM

Any suggestions?

Thank you!

GTBrandon · 03-02-2021, 12:57 PM

You check the air filters?

randrews15 · 03-03-2021, 01:05 PM

What is the last time you replaced your plugs? Modded N55 motors typically need plugs changed every 15k and to be one step colder than stock plugs. I'd also look for slight vacuum leaks that may not be bad enough to throw a code. Lots of possibilities here without out knowing the mileage and history of the car.

X5 MAN · 03-03-2021, 03:50 PM

Check the MAF sensors

They may have gone bad.

Just one more thing to check as I had a similar problem .

03-01-2021, 02:59 PM	#1
john6000777 john6000777 2 Rep 7 Posts Drives: 2013 X5 35i Join Date: Oct 2019 Location: Connecticut iTrader: (0)	Sluggish Acceleration Hey what’s up guys I was wondering if anyone could help me figure out what my problem is. I have a 2013 X5 35i tuned on MHD Stage 1. Long story short: the car has its moments when it feels extremely sluggish with bad throttle response and my MPG goes down the drain. It almost feels like an "unofficial" limp mode because I don’t get any codes or engine light. Usually on a cold startup the car feels fine but as I drive I can almost feel when the unofficial limp mode kicks in. This has been going on for about the past month and I feel the symptoms have been getting worse. Now, I am almost always in the unofficial limp mode. I decided to take two logs: one when the car feels normal and another when it’s sluggish. I’m not a pro at reading logs so the only thing I noticed is that my Boost target drops from peaking at 13.4lbs when normal to only ~10.3lbs when the unofficial limp mode kicks in. Here is the log when the car is sluggish: https://datazap.me/u/johnogandouconn...L0XOEbO4pAoZuM Any suggestions? Thank you!
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03-02-2021, 12:57 PM	#2
GTBrandon Captain 260 Rep 709 Posts Drives: 13' M3 Competition Join Date: Dec 2016 Location: Northern VA iTrader: (2)	You check the air filters?
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03-03-2021, 01:05 PM	#3
randrews15 Lieutenant 289 Rep 553 Posts Drives: 2012 E93 M3 Le Mans Blue Join Date: Nov 2012 Location: Parrish, FL iTrader: (1)	What is the last time you replaced your plugs? Modded N55 motors typically need plugs changed every 15k and to be one step colder than stock plugs. I'd also look for slight vacuum leaks that may not be bad enough to throw a code. Lots of possibilities here without out knowing the mileage and history of the car.
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03-03-2021, 03:50 PM	#4
X5 MAN Lieutenant 78 Rep 491 Posts Drives: 2011X5 50iM-Sport;2016X3 35i M Join Date: Aug 2018 Location: USA iTrader: (0)	Check the MAF sensors They may have gone bad. Just one more thing to check as I had a similar problem .
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