Loss of acceleration at WOT, no CEL

MMMCOOKIES55 · 02-19-2014, 09:23 AM

Hey guys,

Not my car, but a friend of mine's. 2007 335 6MT bone stock with 48,000 miles on it. Intermittently upon cruising speed, a tiny little motor noise can be heard in the engine compartment (right side), whenever that noise is present and you go WOT or even 50% throttle, it feels as if it is in limp mode, severe loss of power. The odd thing is there is no check engine light, no codes present. any ideas before he heads to the dealer?

MDORPHN · 02-19-2014, 09:25 AM

Charge pipe. Either broken or detached.

Also, check cold-side connection to intercooler.

Neil

Ingeniator · 02-19-2014, 09:26 AM

Boost leak I bet. Odd that it isn't throwing codes though.

MMMCOOKIES55 · 02-19-2014, 09:26 AM

See I was figuring a boost leak when he described it to me but the lack of engine codes threw me for a loop.

MMMCOOKIES55 · 02-19-2014, 09:34 AM

Will check for boost leaks later this morning, will report back. Still doesn't explain the random motor noise?

Ingeniator · 02-19-2014, 09:50 AM

Quote:

Originally Posted by MMMCOOKIES335...

Will check for boost leaks later this morning, will report back. Still doesn't explain the random motor noise?

Your probably hearing the leak open up. I had one on my diesel on the intercooler boot. It would open at ~22psi and then seal back up at ~10psi. You would hear a clunk pop when it opened up.

MMMCOOKIES55 · 02-19-2014, 09:51 AM

Ah, didn't think about that^.

MMMCOOKIES55 · 02-19-2014, 01:58 PM

Well no vacuum leaks to speak of, anywhere. Just a thought, could the diverter valves be sticking? or faulty? They passed the vacuum leak test, just curious? I did find two vacuum tees broken and replaced those along with all the lines but that didn't change anything.

MDORPHN · 02-19-2014, 02:14 PM

Quote:

Originally Posted by MMMCOOKIES335...

Well no vacuum leaks to speak of, anywhere. Just a thought, could the diverter valves be sticking? or faulty? They passed the vacuum leak test, just curious? I did find two vacuum tees broken and replaced those along with all the lines but that didn't change anything.

OK, but what about the pressurized side of things -- the charge pipe (where it attaches to the throttle body) and the intercooler to charge pipe connection?

Neil

MMMCOOKIES55 · 02-19-2014, 02:26 PM

Charge pipe is fine, not cracked. Took the bumper off and checked both sides (cool and hot side) and nothing.

MDORPHN · 02-19-2014, 02:37 PM

Quote:

Originally Posted by MMMCOOKIES335...

Charge pipe is fine, not cracked. Took the bumper off and checked both sides (cool and hot side) and nothing.

Odd. And I take it that the C-clamp holding the charge pipe to the throttle body is in place?

Neil

MMMCOOKIES55 · 02-19-2014, 02:45 PM

Yes, in place. It is odd. Been scratching my head all day. I am to the point where I should install my JB4 onto his car so I can log and check things that way.

Jeff@TopGearSolutions · 02-19-2014, 03:12 PM

To throw the underboost code it needs to experience an underboost condition for 3-4 seconds so try Wide open throttle for at least 4 seconds during the power loss.

Also is there any sort of shutter or engine vibration during this time or just a loss of power?

If there is vibration and engine shuttering then get out of the throttle, right away.

It should throw a code on the 3rd limp mode if it didn't the first few times. There might be a shadow code stored which cannot be seen by regular code readers.

If the exhaust gets louder it may be a wastegate or turbo solenoid issue.

MMMCOOKIES55 · 02-20-2014, 09:38 AM

Update: and if someone could explain how that would be great unless it is pure coincidence and the symptoms have just subsided for now, but I swapped the diverter valves from my car to his and buttoned everything back up, the car is running great, no issues.

Ingeniator · 02-20-2014, 11:15 AM

Quote:

Originally Posted by MMMCOOKIES335...

Update: and if someone could explain how that would be great unless it is pure coincidence and the symptoms have just subsided for now, but I swapped the diverter valves from my car to his and buttoned everything back up, the car is running great, no issues.

Makes perfect sense. His diverter valves were not holding the boost. They were either popping open or would not close. That would be a boost leak just not to atmosphere.

MMMCOOKIES55 · 02-20-2014, 11:25 AM

that does make sense, thanks everyone for the input!

Jeff@TopGearSolutions · 02-20-2014, 01:14 PM

Quote:

Originally Posted by MMMCOOKIES335...

Update: and if someone could explain how that would be great unless it is pure coincidence and the symptoms have just subsided for now, but I swapped the diverter valves from my car to his and buttoned everything back up, the car is running great, no issues.

Makes sense indeed. I'm glad you found this because it also goes to show how the stock DV can potentially leak. There are a few guys who claim the stock DV don't leak and it's not necessary to upgrade them. This is proof right here that even on a stock car they will fail.

MMMCOOKIES55 · 02-20-2014, 01:15 PM

Quote:

Originally Posted by Jeff@TopGearSolutions

Makes sense indeed. I'm glad you found this because it also goes to show how the stock DV can potentially leak. There are a few guys who claim the stock DV don't leak and it's not necessary to upgrade them. This is proof right here that even on a stock car they will fail.

Right, exactly. Lot of debate about DV's on here. Makes me want to fork out for some Forged DV's.

Big Busa · 05-18-2014, 08:54 AM

Hmmmm! Could be the answer I've been looking for! Gonna check my dv today!

02-19-2014, 09:23 AM	#1
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Loss of acceleration at WOT, no CEL Hey guys, Not my car, but a friend of mine's. 2007 335 6MT bone stock with 48,000 miles on it. Intermittently upon cruising speed, a tiny little motor noise can be heard in the engine compartment (right side), whenever that noise is present and you go WOT or even 50% throttle, it feels as if it is in limp mode, severe loss of power. The odd thing is there is no check engine light, no codes present. any ideas before he heads to the dealer?
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02-19-2014, 09:25 AM	#2
MDORPHN Colonel 297 Rep 2,898 Posts Drives: AW 1M Join Date: Oct 2010 Location: Wash, DC iTrader: (0)	Charge pipe. Either broken or detached. Also, check cold-side connection to intercooler. Neil
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02-19-2014, 09:26 AM	#3
Ingeniator Major 34 Rep 1,093 Posts Drives: 07 335XI(90) 09 135I(82) Join Date: Nov 2013 Location: Fort Mac, Alberta iTrader: (1)	Boost leak I bet. Odd that it isn't throwing codes though. __________________ 07 335XI (A008006) 6AT ~94K miles JB4 G5 ISO VSRF DP's 09 135I M (VK80379) 6MT. Race Project car. 1) Install Cobb/piggyback? and Motiv 600 Kit[HTA3076R w/ tial .82] 2) JRZ or Moton suspension. 3) Build high flow intake manifold with multi-port fuel and relocate OFH 4) Build full cage 5) Complete staged twin setup with HTA4205R [w/Tial 1.16] 6) Complete dry sump system
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02-19-2014, 09:26 AM	#4
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	See I was figuring a boost leak when he described it to me but the lack of engine codes threw me for a loop.
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02-19-2014, 09:34 AM	#5
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Will check for boost leaks later this morning, will report back. Still doesn't explain the random motor noise?
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02-19-2014, 09:51 AM	#7
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Ah, didn't think about that^.
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02-19-2014, 01:58 PM	#8
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Well no vacuum leaks to speak of, anywhere. Just a thought, could the diverter valves be sticking? or faulty? They passed the vacuum leak test, just curious? I did find two vacuum tees broken and replaced those along with all the lines but that didn't change anything.
	Appreciate 0 Quote

02-19-2014, 02:26 PM	#10
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Charge pipe is fine, not cracked. Took the bumper off and checked both sides (cool and hot side) and nothing.
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02-19-2014, 02:45 PM	#12
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Yes, in place. It is odd. Been scratching my head all day. I am to the point where I should install my JB4 onto his car so I can log and check things that way.
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02-19-2014, 03:12 PM	#13
Jeff@TopGearSolutions 3461 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	To throw the underboost code it needs to experience an underboost condition for 3-4 seconds so try Wide open throttle for at least 4 seconds during the power loss. Also is there any sort of shutter or engine vibration during this time or just a loss of power? If there is vibration and engine shuttering then get out of the throttle, right away. It should throw a code on the 3rd limp mode if it didn't the first few times. There might be a shadow code stored which cannot be seen by regular code readers. If the exhaust gets louder it may be a wastegate or turbo solenoid issue.
	Appreciate 0 Quote

02-20-2014, 09:38 AM	#14
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	Update: and if someone could explain how that would be great unless it is pure coincidence and the symptoms have just subsided for now, but I swapped the diverter valves from my car to his and buttoned everything back up, the car is running great, no issues.
	Appreciate 0 Quote

02-20-2014, 11:25 AM	#16
MMMCOOKIES55 Major 350 Rep 1,376 Posts Drives: '17 M3 ZCP/ '16 ATS-V Join Date: Oct 2009 Location: Apex, NC iTrader: (3)	that does make sense, thanks everyone for the input!
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05-18-2014, 08:54 AM	#19
Big Busa Private 14 Rep 78 Posts Drives: 15' 335i M Sport Saloon, soon! Join Date: Jun 2013 Location: NC iTrader: (0) Garage List 2013 honda accord e ... [0.00] 2008 Suzuki Hayabusa [0.00] 2011 Nissan Maxima [0.00]	Hmmmm! Could be the answer I've been looking for! Gonna check my dv today!
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