[sturat]

I have a 2008 335xi with a Active BOV and 171,000 miles. I have been trying to figure out where the boost leak is and I have not had much luck. I get a a 30ff when I go above 3000 rpm and I am pushing the engine. The 1/2 engine light goes on and a warning chime but no loss in pressure I can feel and no limp mode. Just makes me back off all the time. I pulled off the charge pipe and fixed the MAF sensor that had been attached with self tapping screws, one of which was sheared off. I'm guessing a previous owners attempt at an install. That really didn't do a lot. When I am driving I have Bimmerlink on and my Boost Pressure can show 7,8 10 psi and then simply drop off to .3, .4 or even .00. Mind you I am not feeling any real loss of power. I see my Boost Pressure Setpoint at 14.2 to 14.7 so I am producing boost. When I have theses crazy low readings and I let up on the gas the waste gate opens and dumps air and the Boost pressure jams up above 10 and starts to drop. I'm not even sure it is the source of my error. I have no clue as to any software modification but I am wondering if there is a sensor going bad as this is intermittent. Hey I have narrowed my Christmas tree of engine errors down to a few and that part is feeling great. Any insight would be appreciated.

[relative4]

Post a log.

[mweisdorfer]

Originally Posted by sturat

I have a 2008 335xi with a Active BOV and 171,000 miles. I have been trying to figure out where the boost leak is and I have not had much luck. I get a a 30ff when I go above 3000 rpm and I am pushing the engine. The 1/2 engine light goes on and a warning chime but no loss in pressure I can feel and no limp mode. Just makes me back off all the time. I pulled off the charge pipe and fixed the MAF sensor that had been attached with self tapping screws, one of which was sheared off. I'm guessing a previous owners attempt at an install. That really didn't do a lot. When I am driving I have Bimmerlink on and my Boost Pressure can show 7,8 10 psi and then simply drop off to .3, .4 or even .00. Mind you I am not feeling any real loss of power. I see my Boost Pressure Setpoint at 14.2 to 14.7 so I am producing boost. When I have theses crazy low readings and I let up on the gas the waste gate opens and dumps air and the Boost pressure jams up above 10 and starts to drop. I'm not even sure it is the source of my error. I have no clue as to any software modification but I am wondering if there is a sensor going bad as this is intermittent. Hey I have narrowed my Christmas tree of engine errors down to a few and that part is feeling great. Any insight would be appreciated.

Spring values of your BOV?

Boost solenoids?

[Saif2018]

Originally Posted by sturat

I have a 2008 335xi with a Active BOV and 171,000 miles. I have been trying to figure out where the boost leak is and I have not had much luck. I get a a 30ff when I go above 3000 rpm and I am pushing the engine. The 1/2 engine light goes on and a warning chime but no loss in pressure I can feel and no limp mode. Just makes me back off all the time. I pulled off the charge pipe and fixed the MAF sensor that had been attached with self tapping screws, one of which was sheared off. I'm guessing a previous owners attempt at an install. That really didn't do a lot. When I am driving I have Bimmerlink on and my Boost Pressure can show 7,8 10 psi and then simply drop off to .3, .4 or even .00. Mind you I am not feeling any real loss of power. I see my Boost Pressure Setpoint at 14.2 to 14.7 so I am producing boost. When I have theses crazy low readings and I let up on the gas the waste gate opens and dumps air and the Boost pressure jams up above 10 and starts to drop. I'm not even sure it is the source of my error. I have no clue as to any software modification but I am wondering if there is a sensor going bad as this is intermittent. Hey I have narrowed my Christmas tree of engine errors down to a few and that part is feeling great. Any insight would be appreciated.

https://bmwtuning.co/bmw-n54-30ff-en...-repair-guide/

You've done the vacumn lines, checked cannisters for leaks/cracks, boost solenoids, IC connections and charge pipe connection points?

Not sure how accurate bimmerlink is, recommended using MHD and posting a Datalog on datazap.me

[sturat]

Thanks for all the input and ideas. I do not own MHD but seems like everyone likes it. I'll have to look into it. I did go through all the vacuum lines looking for leaks. I should just replace them as it is not expensive and after this many miles could be an issue with a small crack. Charge pipe connection is solid with the gasket pliable and the Silicone sleeve secured. Ill need to look into the boost solenoids too.

[sturat]

I ended up changing the boost solenoids as they were original to the car 173,000 miles ago. I still want to replace the hoses as those have a date code of 07 and are just a bit hard...but it fired right up and is running like a dream. No more boost leak error when I open it up. Thanks for all the input.

[stewbets]

Noice! Thanks for the update!