[CRJ68]

Hello,
2011 335D. Got a "engine malfunction , reduced power" warning.

pulledsome codes
4530 Charging pressure control
4B81 EGR
4C2C air mass sensor area MAF?
4868 (no definition) also EGR?

The light clears. I've tracked out all I could get to rather easily and checked vacuum hoses, and looked for oil leaks etc...everything looks OK etc.

What I've noticed is when driving and producing boost a sort of fluttering or flapping sound is heard. goes away when car shifts (RPM drops) and then again when revs come up and Im assuming boost is being produced again. No noises in park/neutral when revving up or letting off.

Driving the car, it's down on power, but not terribly. Even when it goes into the "reduced capacity" thing it's not severe like a real limp mode. Car is also 100% stock 94K miles.

update:
I found today that if I drive like a granny (not the one from Pasadena) all is well. If I get into the boost a little I hear the flappy sound.
If I get into the boost heavy it will throw the "engine malfunction" light up. I'm no turbo expert so I'm not sure what all happens when you build boost. what kicks on, or opens, etc...

Maybe it's a solenoid?

[335dlci]

How are your vacuum lines looking ok?

[CRJ68]

thanks for the response. yeah they look good. At least all the ones I can get to and check.

If I can figure out what is happening when the small turbo starts boosting, I can maybe track down the noise. It's not really loud like if A/C is blowing I wont hear it. Sounds a bit like a flappy air leak or maybe a solenoid/relay rattling.


A little confused about parts involved; pressure converters valves on US vs Euro cars. mine is US...

I'm guessing if I can replace that vacuum stuff above the turbos, that might cure it.

[Nadir Point]

Not enough boost commanded, high EGT = the dreaded engine malfunction warning. Mine does it just because it's too over-fueled if I don't keep the revs up with my foot in it.

[335dlci]

Originally Posted by CRJ68

thanks for the response. yeah they look good. At least all the ones I can get to and check.

If I can figure out what is happening when the small turbo starts boosting, I can maybe track down the noise. It's not really loud like if A/C is blowing I wont hear it. Sounds a bit like a flappy air leak or maybe a solenoid/relay rattling.


A little confused about parts involved; pressure converters valves on US vs Euro cars. mine is US...

I'm guessing if I can replace that vacuum stuff above the turbos, that might cure it.

How old are they?

[CRJ68]

Originally Posted by Nadir Point

Not enough boost commanded, high EGT = the dreaded engine malfunction warning. Mine does it just because it's too over-fueled if I don't keep the revs up with my foot in it.

Exhaust temps?

[CRJ68]

Originally Posted by 335dlci

How old are they?

I'm assuming everything is stock @ 94K miles. there is some info in carfax about turbo work many years ago on the car. I've owned it 2 years. this is first real issue besides water pump I've had.

I hear the noise at about 2500RPM and then I let the car shift and RPM drop it goes away.

[Nadir Point]

It's hard to say, but that's what it sounds like to me, based on available evidence. Gotta figure out what's going fubar on the intake tract.

[CRJ68]

Originally Posted by Nadir Point

It's hard to say, but that's what it sounds like to me, based on available evidence. Gotta figure out what's going fubar on the intake tract.

do you know what opens, closes, changes when small turbo starts to boost?

If I drive the car like my wife would, you would never know there was a problem.

I saw post from YOZH (?) about electric valves and pressure actuators. Seems a sensor is feeling the boost and trying to make something happen and that is causing a leak or a chatter.

[Nadir Point]

Yeah, those guys will be the ones to decode the details. I'm just an old-school diesel guy with a feel for how they run.

Originally Posted by CRJ68

If I drive the car like my wife would, you would never know there was a problem.

That's because it's getting enough air until you put your foot in it and the turbos fail for whatever reason.

Mine don't fail - they're just not big enough. And nobody around here want to work on it anymore, thanks to the EPA diesel crackdown.

[CRJ68]

Originally Posted by Nadir Point

Yeah, those guys will be the ones to decode the details. I'm just an old-school diesel guy with a feel for how they run.

Thanks- I'm an old school muscle car guy...so not a big brain for modern cars. ran out of brain space long ago anyways..

Its not 110 degrees today so, I unplugged and plugged back in all sensors and junk I could find in the vacuum EGR system.

Took it out and let er' rip. I still hear the sound at about 2500 to 2800 RPM (flappy paper type sound) I revved further which before was giving me the fault. (the flappy got a little louder) no fault this time. I'm assuming at some point the large turbo is producing here and the flappy sound went away...and by then I'm doing 110 and had to slow down.

I put it in "manual" and held it at 2500 rpm while driving the noise is constantly there. ...need to put one of my kids up under the hood I guess.

[CRJ68]

Originally Posted by Nadir Point

Yeah, those guys will be the ones to decode the details. I'm just an old-school diesel guy with a feel for how they run.



That's because it's getting enough air until you put your foot in it and the turbos fail for whatever reason.

Ahhh...That's a good thought right there- I do notice my car is a little more stinky lately, like it's running rich.

[Nadir Point]

The DPF's not gonna last long like that either. You are in an M57 death spiral.

[CRJ68]

Originally Posted by Nadir Point

The DPF's not gonna last long like that either. You are in an M57 death spiral.

Message received Thanks again !

[CRJ68]

At this point I gotta think it's a leak. I try and use technical terms whenever possible...

at about 2200 rpm its a blip-blip-blip-blip

at 3000rpm it's a louder more spaced out blap blap blap blap

[335dlci]

Originally Posted by CRJ68

I'm assuming everything is stock @ 94K miles. there is some info in carfax about turbo work many years ago on the car. I've owned it 2 years. this is first real issue besides water pump I've had.

I hear the noise at about 2500RPM and then I let the car shift and RPM drop it goes away.

So at 94k they are way overdue. Especially stock rubber lines.

[CRJ68]

Originally Posted by 335dlci

So at 94k they are way overdue. Especially stock rubber lines.

Ok- I'll get after them. Thanks

Got these codes today

4b7f EGR Pressure Before turbine signal
4530 charging pressure Control deviation
P0299 Turbo Underboost

Just posting in case someone has similar issue....and finds this one day

[335dlci]

Originally Posted by CRJ68

Ok- I'll get after them. Thanks

Got these codes today

4b7f EGR Pressure Before turbine signal
4530 charging pressure Control deviation
P0299 Turbo Underboost

Just posting in case someone has similar issue....and finds this one day

Yeah do your lines. A lot of issues happen from lack of vacuum
Been documented since mid 2010s. I have done mine twice...

[Yozh]

4530 is basically not enough boost. The blap-blap-blap you are hearing could be a good boost leak. As was suggested replace your vac lines while you are at it. But go over the whole thing and make sure you have no boost leaks.

[CRJ68]

Originally Posted by Yozh

4530 is basically not enough boost. The blap-blap-blap you are hearing could be a good boost leak. As was suggested replace your vac lines while you are at it. But go over the whole thing and make sure you have no boost leaks.

Will do

I did search all the old posts for days and days ...and saw everything from vacuum lines to turbo seals. motor mounts, AC line weights, EGR valves, MAF sensors.
Once I got the P0299 error and searched that, things definitely got a little more specific

Hopefully I'll get it taken care of here this weekend.
appreciate it everyone.

[CRJ68]

Finally tore into it. What a pain in the azz...

Some hoses looked pretty nasty and the vacuum control valve where the red hose goes, only holds pressure on one side (the black hose side)

I'm guessing that the culprit. Unless that's normal? it has that cap thing on the end and thats where the "leak" is.

this thing

https://www.ecstuning.com/b-genuine-...MaAnhwEALw_wcB

[Yozh]

Originally Posted by CRJ68

Finally tore into it. What a pain in the azz...

Some hoses looked pretty nasty and the vacuum control valve where the red hose goes, only holds pressure on one side (the black hose side)

I'm guessing that the culprit. Unless that's normal? it has that cap thing on the end and thats where the "leak" is.

this thing

https://www.ecstuning.com/b-genuine-...MaAnhwEALw_wcB

Input side shall hold vacuum. It’s normal.

https://youtu.be/pcSvCFIqP-w