335i jerk when let off throttle under WOT

westchester335i · 04-08-2014, 09:59 PM

I have a 6at 335i with 40k miles with JB4, tial BOV, strett CP and DCI. I have always had this issue after the tune was installed but I don't push my car enough to really realize how annoying it is.

Basically if I am WOT in any gear and I let off the throttle real quick the car jerks/bucks sometimes. Not all the time but 40% of the time it bucks and jerks. I will give two examples where it almost always occurs and I am just wondering if this is normal or not.

The buck/jerk is very noticeable. Everyone in the car feels it.

1. When in manual mode lets say in third gear going WOT and quickly let off throttle around high rpm car will buck/jerk.

2. When flooring car at high speeds and letting of throttle real quick car will sometimes buck and jerk.

No codes I sometimes get a boost leak code 30FF code once in a while but nothing else. Spark Plugs were changed 5k miles ago. Injectors were changed at 25k miles. And the HPFP is the original pump.

What could this be or this normal behavior?

matty231 · 04-09-2014, 03:15 AM

Mine does this too, but I think it's normal, there is a lot of power on the tranny at that RPM, so if you back off I think the shock knocks the power train a bit ... I get it a lot if i'm in first or second & let of the gas, the car sort of lurches a few times, but yes I wouldn't worry about it, just avoid doing it i'd think.

iturbo_bmw · 04-09-2014, 12:18 PM

happens to me as well. i figured it was normal cause it logically made sense to me

AllBlackBimmer · 04-09-2014, 01:20 PM

I bet if you would drive a Ferrari the same way, when letting off the gas it would "jerk" a little too due to the performance of the car. Obvious our cars don't have as much HP, but the same physics would still apply.

I would assume when you are pushing the car hard at WOT, your RPMs are 5-7k? ...and then letting off the gas and the RPMs drop to like 500-1k...

e92_enthusiast_1 · 04-09-2014, 01:24 PM

So if you let off the throttle smooth it's not the same symptom? It's probably related no? Same if you turn off JB4?

335BOY · 04-09-2014, 01:30 PM

Why would you guys keep hammering the throttle and getting out of it so fast? Especially if it causes grief? OP has all kinds of mods....ya think that might have something to do with it?

04-08-2014, 09:59 PM	#1
westchester335i First Lieutenant 34 Rep 356 Posts Drives: Sour Diesel and Haze Join Date: Oct 2013 Location: Westchester iTrader: (2)	335i jerk when let off throttle under WOT I have a 6at 335i with 40k miles with JB4, tial BOV, strett CP and DCI. I have always had this issue after the tune was installed but I don't push my car enough to really realize how annoying it is. Basically if I am WOT in any gear and I let off the throttle real quick the car jerks/bucks sometimes. Not all the time but 40% of the time it bucks and jerks. I will give two examples where it almost always occurs and I am just wondering if this is normal or not. The buck/jerk is very noticeable. Everyone in the car feels it. 1. When in manual mode lets say in third gear going WOT and quickly let off throttle around high rpm car will buck/jerk. 2. When flooring car at high speeds and letting of throttle real quick car will sometimes buck and jerk. No codes I sometimes get a boost leak code 30FF code once in a while but nothing else. Spark Plugs were changed 5k miles ago. Injectors were changed at 25k miles. And the HPFP is the original pump. What could this be or this normal behavior?
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04-09-2014, 03:15 AM	#2
matty231 Second Lieutenant 19 Rep 243 Posts Drives: '08 E90 335i M Join Date: May 2008 Location: Kiwi Land! iTrader: (0)	Mine does this too, but I think it's normal, there is a lot of power on the tranny at that RPM, so if you back off I think the shock knocks the power train a bit ... I get it a lot if i'm in first or second & let of the gas, the car sort of lurches a few times, but yes I wouldn't worry about it, just avoid doing it i'd think. __________________ 2008 BMW 335i M-Sport Black Saph w/ Dakato Black \| M-Sport \| Sunroof \| iDrive \| 6SP Steptronic \| Comfort Access \| Lights Package \| JDM Spec
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04-09-2014, 12:18 PM	#3
iturbo_bmw Major 84 Rep 1,099 Posts Drives: 335i, 530i Join Date: Oct 2012 Location: San Jose iTrader: (0)	happens to me as well. i figured it was normal cause it logically made sense to me
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04-09-2014, 01:20 PM	#4
AllBlackBimmer Colonel 815 Rep 2,869 Posts Drives: 2019 X3 m40i Join Date: Aug 2011 Location: USA iTrader: (-1)	I bet if you would drive a Ferrari the same way, when letting off the gas it would "jerk" a little too due to the performance of the car. Obvious our cars don't have as much HP, but the same physics would still apply. I would assume when you are pushing the car hard at WOT, your RPMs are 5-7k? ...and then letting off the gas and the RPMs drop to like 500-1k... __________________ 2019 X3 m40i:Carbon Black:Executive:Premium:Adaptive:Vernasca:699M:HK: Ambient:IND trim:M Mirrors:15mm spacers:Maxton lip:20% tint windows/pano:dsg paddles:TLG mudflaps 2008 328i E90 Jet Black:6MT:RWD:Premium:Sport:Xenon:MTEC V3 AEs:Front Splitters:CF spoiler:19" VMR FF v710
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04-09-2014, 01:24 PM	#5
e92_enthusiast_1 Lieutenant Colonel 35 Rep 1,652 Posts Drives: '10 AW/CR e92 6mt 335i Join Date: Mar 2012 Location: Chandler, AZ iTrader: (1) Garage List 2010 BMW 335i [0.00]	So if you let off the throttle smooth it's not the same symptom? It's probably related no? Same if you turn off JB4? __________________ COBB AP Stg 2+ FMIC Aggressive \| VRSF 3" Catless DP \| COBB FMIC \| BMS DCI \| CP-e Metal Charge Pipe \| 370+ whp/435+ lb.ft torque Last edited by e92_enthusiast_1; 04-09-2014 at 01:33 PM..
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04-09-2014, 01:30 PM	#6
335BOY Colonel 197 Rep 2,802 Posts Drives: 2017 SQ5 Join Date: Jan 2013 Location: Toronto iTrader: (0)	Why would you guys keep hammering the throttle and getting out of it so fast? Especially if it causes grief? OP has all kinds of mods....ya think that might have something to do with it?
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