Powertrain Malfunction- post exhaust install

WhiteWalker · 07-03-2014, 02:38 PM

Recently installed a Meistershaft GTC on my '11 550i Dinan S2.

Under medium+ and steady throttle-- 5th and 6th gear , the car delivers a POWERTRAIN MALFUNCTION since installing my exhaust.

The boost seems to vanish and the car is not lifeless, but certainly running with significantly less power.

Recently had it at BMW where my mechanic advised of a potential vacuum left open when the new exhaust was put on. It was supposedly corrected and I also upgraded to Dinan S3.

First time out of the shop where I had the room, same result Powertrain Malfunction.

Any advise or thoughts would be appreciated.

Dhu · 07-07-2014, 04:10 PM

Had a very similar thing happen when I installed the dinan exhaust. Ultimately 10 months later, the check engine light came on and I took it to the dealership. They replaced all 8 fuel injectors...haven't a problem since....

ferrarif1 · 07-07-2014, 08:13 PM

Does this happen with the exhaust valve open? When I had my M5 exhaust, I forgot to connect the vacuum valves and the increased back pressure caused a reduction in boost / drivetrain malfunction. Reconnecting the valves to allow full flow solved the problem.

WhiteWalker · 07-07-2014, 09:22 PM

Actually figured this one out with out a trip back to the dealer.

The seal on the vacuum bypass hose under the hood failed and was leaking air. I cut the hose down a 1/2" and resealed.

No further problems and back to full power!

Very strange feeling driving with 0 turbo assist, all motor.

07-03-2014, 02:38 PM	#1
WhiteWalker Private First Class 16 Rep 136 Posts Drives: BMW Join Date: Feb 2013 Location: USA iTrader: (-1)	Powertrain Malfunction- post exhaust install Recently installed a Meistershaft GTC on my '11 550i Dinan S2. Under medium+ and steady throttle-- 5th and 6th gear , the car delivers a POWERTRAIN MALFUNCTION since installing my exhaust. The boost seems to vanish and the car is not lifeless, but certainly running with significantly less power. Recently had it at BMW where my mechanic advised of a potential vacuum left open when the new exhaust was put on. It was supposedly corrected and I also upgraded to Dinan S3. First time out of the shop where I had the room, same result Powertrain Malfunction. Any advise or thoughts would be appreciated.
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07-07-2014, 04:10 PM	#2
Dhu Private 2 Rep 76 Posts Drives: 2011 550 Join Date: May 2013 Location: SF Bay area iTrader: (0)	same thing Had a very similar thing happen when I installed the dinan exhaust. Ultimately 10 months later, the check engine light came on and I took it to the dealership. They replaced all 8 fuel injectors...haven't a problem since.... __________________ _______________________________________________ Dinan Stage 5 550i, Dinan springs, Dinan Exhaust, Shockware
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07-07-2014, 08:13 PM	#3
ferrarif1 Major 320 Rep 1,061 Posts Drives: F85, G05, E46M3 Join Date: Mar 2013 Location: Boston iTrader: (5)	Does this happen with the exhaust valve open? When I had my M5 exhaust, I forgot to connect the vacuum valves and the increased back pressure caused a reduction in boost / drivetrain malfunction. Reconnecting the valves to allow full flow solved the problem.
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07-07-2014, 09:22 PM	#4
WhiteWalker Private First Class 16 Rep 136 Posts Drives: BMW Join Date: Feb 2013 Location: USA iTrader: (-1)	Actually figured this one out with out a trip back to the dealer. The seal on the vacuum bypass hose under the hood failed and was leaking air. I cut the hose down a 1/2" and resealed. No further problems and back to full power! Very strange feeling driving with 0 turbo assist, all motor.
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