Problems after CP blowout

SoFloE82 · 03-23-2019, 04:20 PM

Looking for some theories on what may be wrong with my car.. this past weekend I finished the benchflash and port meth injection install on my 2013 135i. After the install the car fired right up. I loaded the MHD JB4 BEF and activated the correct JB4 menu for backend flash operation. The car started and drove well (under light conditions) for about 20 miles and a few on/off cycles.

Finally I was confident enough in the operation to push the car and see how it felt under boost with the newly raised targets. I was in map1 still and went WOT in 3rd gear from about 2500rpm. The moment the boost kicked up I felt an immediate drop in power and I knew something was wrong. I limped it to work where I opened the hood and saw the connection from the hot side of the intercooler to the CP had blown off. Its a hose connection to the aftermarket CP. I must have not seated it well after install.

I reconnected it and figured all was well, but when I restarted the car it still wasn't right. It would start fine and sounded normal, but when the revs dropped from start to idle, the car would start shaking. Seemed like a missfire but no codes. If I tried to give it gas, it sounded like 2step except I definitely don't have 2step. I checked all the connections I could see but didn't find anything loose. I had it towed to my local shop and they're going to look at it on Monday. I need to have the valve cover gasket replaced anyway.

Anyone have an issue like this before where the car wont idle and when you give it gas it sounds like 2step launch control? Any hints would be appreciated. Thanks!

Mike@N54Tuning.com · 03-23-2019, 04:45 PM

Have you checked if anything else popped off? Throttle body side?

Mike

SoFloE82 · 03-23-2019, 05:11 PM

Thanks, Mike. I was in the burning sun so I couldn’t dig too deep but I did take a feel on the back side of the throttle body for the vent connection and electric connection. Both felt solid. I did disconnect the CP from the throttle body to seat the lower portion of the CP so I was thinking maybe the o-ring unseated but I doubt that would cause this much of an issue if the car ran ok with the chargepipe fully disconnected (except while shifting (DCT)).

iminhell1 · 03-24-2019, 08:19 PM

Reset learned fuel trims and throttle.
I had similar on my N54, drove 110 miles with no intercooler. My fuel trims adapted to having no boost as did the throttle angles to match TQ requested. I had to reset both and drive about 5-10 miles for it to come back to normal.

03-23-2019, 04:20 PM	#1
SoFloE82 Private 6 Rep 43 Posts Drives: 135i Join Date: Sep 2011 Location: SoFlo iTrader: (0)	Problems after CP blowout Looking for some theories on what may be wrong with my car.. this past weekend I finished the benchflash and port meth injection install on my 2013 135i. After the install the car fired right up. I loaded the MHD JB4 BEF and activated the correct JB4 menu for backend flash operation. The car started and drove well (under light conditions) for about 20 miles and a few on/off cycles. Finally I was confident enough in the operation to push the car and see how it felt under boost with the newly raised targets. I was in map1 still and went WOT in 3rd gear from about 2500rpm. The moment the boost kicked up I felt an immediate drop in power and I knew something was wrong. I limped it to work where I opened the hood and saw the connection from the hot side of the intercooler to the CP had blown off. Its a hose connection to the aftermarket CP. I must have not seated it well after install. I reconnected it and figured all was well, but when I restarted the car it still wasn't right. It would start fine and sounded normal, but when the revs dropped from start to idle, the car would start shaking. Seemed like a missfire but no codes. If I tried to give it gas, it sounded like 2step except I definitely don't have 2step. I checked all the connections I could see but didn't find anything loose. I had it towed to my local shop and they're going to look at it on Monday. I need to have the valve cover gasket replaced anyway. Anyone have an issue like this before where the car wont idle and when you give it gas it sounds like 2step launch control? Any hints would be appreciated. Thanks!
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03-23-2019, 04:45 PM	#2
Mike@N54Tuning.com Joint Chiefs of Staff 4912 Rep 115,980 Posts Drives: 2007 335i, 2015 M3 Join Date: Dec 2008 Location: N54tuning.com iTrader: (89)	Have you checked if anything else popped off? Throttle body side? Mike
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03-23-2019, 05:11 PM	#3
SoFloE82 Private 6 Rep 43 Posts Drives: 135i Join Date: Sep 2011 Location: SoFlo iTrader: (0)	Thanks, Mike. I was in the burning sun so I couldn’t dig too deep but I did take a feel on the back side of the throttle body for the vent connection and electric connection. Both felt solid. I did disconnect the CP from the throttle body to seat the lower portion of the CP so I was thinking maybe the o-ring unseated but I doubt that would cause this much of an issue if the car ran ok with the chargepipe fully disconnected (except while shifting (DCT)).
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03-24-2019, 08:19 PM	#4
iminhell1 C2H5OH 3915 Rep 2,144 Posts Drives: 2010 SG 135i auto Join Date: May 2015 Location: Darwin, MN iTrader: (1)	Reset learned fuel trims and throttle. I had similar on my N54, drove 110 miles with no intercooler. My fuel trims adapted to having no boost as did the throttle angles to match TQ requested. I had to reset both and drive about 5-10 miles for it to come back to normal.
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