Boost leak?

sniper7799_9977

New Member
Mar 22, 2021
9
0
0
Hey guys

Just got my car back from the mechanic after having the 16T turbos installed on my 2006 E92 N54, Took it for a test drive and all was good then the next day done the same thing but got a engine light (cylinder 5 misfire) so i pulled over turned the car off and cleared the codes and it hasn't came back but now I've got no boost and running lean

mechanic has told me the turbos/vacuum lines etc are fine so i replaced the boost solenoids and diverter valves thinking that may be the cause but it didn't resolve it

All the parts replaced when turbos got installed
HPFP
Vanos Solenoids
Thermostat,
Charge pipe
Intercooler
inlets
Radiator
o2 sensors
RB PCV

car is also catless with downpipes

Any ideas what else could cause no boost?
 
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sniper7799_9977

New Member
Mar 22, 2021
9
0
0
Probably not without blowing oil everywhere. I'm just throwing out places to check. Did you get any logs? They might show something.
No logs yet, have to order another Mhd adapter, I’ve noticed some oil around the vacuum pump? I pulled the hose of and the vacuum seems to stuttering its not a steady flow, also brake pedal is abit stiff on cold start, would a failing/leaking vacuum pump cause low/no boost?
 

NoGuru

Lieutenant
Jan 9, 2018
955
402
0
Just North of Detroit
Ride
BMW 335is
No logs yet, have to order another Mhd adapter, I’ve noticed some oil around the vacuum pump? I pulled the hose of and the vacuum seems to stuttering its not a steady flow, also brake pedal is abit stiff on cold start, would a failing/leaking vacuum pump cause low/no boost?
I can't answer that. I wonder if you have a clogged or failing PCV system. Might be another thing to look at.
 

Slowagon54

Specialist
Aug 21, 2020
53
13
0
No Boost because you are running lean and dme is limiting power. Check the o2 sensors... they may have been damaged during install? A log would be great of course
 

sniper7799_9977

New Member
Mar 22, 2021
9
0
0
No Boost because you are running lean and dme is limiting power. Check the o2 sensors... they may have been damaged during install? A log would be great of course
That’s the thing, the car was boosting then just stopped the next day also not getting any errors on idrive, very odd

could a faulty/leaking fuel injector cause no boost like that without any codes?
 

Slowagon54

Specialist
Aug 21, 2020
53
13
0
4th gear, start WOT on 3k rpm... if car is running fine. In your case i would just try to get a log to see what is happening. No need to go WOT until redline of course.
 
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