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      11-16-2017, 11:04 PM   #1
New Member

Drives: 2008 135i 6mt n54
Join Date: Nov 2017
Location: Arkansas

iTrader: (0)

Unhappy What could cause late boosting?

Hey everyone! I need some help/input before i go any further. Im new to the site and the n54 for the most part. I have a 08 135i, n54, 6mt. All stock with stg1 mhd flash. Recently I had a devistating accident on passenger side that took out all lighting wiring and components , ambient air sensor, and radiator fan wiring. The upside is that nothing in the engine bay was harmed except the oil cooler. The downside is the insurance would only total it out because the damage was more than what i owe. Being a mechanic i decided to fix it myself cuz i love the car too much to let it go.

The car ran perfect before the wreck. After fixing control arms and oil cooler i took it for a spin (all wiring damage as described above has not been attended to yet) and zero power and engine starts missing. Run codes and cyl 1 and 3 are missing. Change those 2 plugs and engine smooth again but still no power. I did more examining and notice the canisters were also damaged so after doing research i bypassed them because i read of many people deleting the cans with no problems. Still nothing. Take another look and thought i found the problem when i noticed the passenger side ic pipe got pulled out during impact (yes, lots of damage but nothing that cant be fixed, so i thought) the o-ring looks fine so i put it back in and everything seemingly clipped back in just fine. The vacuum line to the front wastegate actuator was untouched but was very loose so i changed all vac lines.

Now the car boosts but its random psi levels and usually doesn't start boosting till around 4600 rpm. Changed boost solenoids and didnt help. Used hand vacuum pump to test wastegates and they're fine. Weird thing is that when engine is cold it feels much better and will sometimes start boosting sooner in the rpm band like around 2500rpm but once the engine warms up i cant get boost till alomst 5k rpm and peak is always a different number ranging from 3psi to 11psi. Could it be the ic pipe o-ring even though it looked fine? The car was perfect b4 the wreck. Need some good input please. My only codes are for radiator fan activation and ambient air sensor. No 30ff or anything like that. Dont have a way to do a boost leak test at the moment and i just need some more experienced advice before moving any further. Thanks in advance!

Heres my most recent log. Not sure if its a good enough log though. Let me know if more info is needed

Last edited by N54guy08; 11-20-2017 at 02:43 PM.. Reason: Title change
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