X5 diesel engine noise - With VID.

[ard]

Originally Posted by ZetaTre

Why's the check engine light on?

.

Ding Ding Ding we have a winner.

AMAZING that someone wants an internet diagnosis "before pulling it apart" yet blithely ignores the CEL and all the codes and info one can find there.

[finnbmw]

Originally Posted by ZetaTre

Why's the check engine light on?

According to OP it's because of the NOx sensors

[Dr. Anthony]

Originally Posted by ZetaTre

Why's the check engine light on?

Have you tried to have someone rev the engine while you try to pin point? You may consider a mechanical stethoscope and touching things around see where's coming from.

It's hard to diagnose noises the internet, but a couple of things coming to mind are the joints in lever controlling the wastegates or the bypass valve that are a little dry or possibly a tear in the membrane of one of said actuators. For example the non-US cars that have a vacuum actuated EGR valve make similar whistle noises when the membrane cracks.

The CEL is on because I need to replace my NOX sensors.

I had my wife rev it a bit while I checked, but couldn't tell where the sound was coming from. If I had to guess, it would be the front or front passenger area of the motor. I'm in Canada. I think our X5s are the same.

[ninja_zx11]

just throwing a wild guess Here to diagnose vacuum related noise.
Disconnect the hose from vacuum pump and try again.but first make sure there is no other error code stored in the DDE.Removing vacuum hose might trigger temporary error codes.

Warning: you must be knowing this but would like to add that Please don't drive with hose removed as you wont have any brakes without vacuum.

[Dr. Anthony]

Originally Posted by ard

Ding Ding Ding we have a winner.

AMAZING that someone wants an internet diagnosis "before pulling it apart" yet blithely ignores the CEL and all the codes and info one can find there.

[Dr. Anthony]

Originally Posted by ninja_zx11

just throwing a wild guess Here to diagnose vacuum related noise.
Disconnect the hose from vacuum pump and try again.but first make sure there is no other error code stored in the DDE.Removing vacuum hose might trigger temporary error codes.

I'll take a look. I can clear the codes with my bavtech cable. The same ones reappear the next day (or whenever I have put on enough mileage) but they're teh same NOX related ones. (my nox sensors need replacing)

I'm also going to try the same with my bypass valve.

[ard]

In air leak can cause odd noised under various running conditions as air if forced through a orifice (think wind instruments) ...AND...unmetered air entering the engine can ALSO cause the DDE to think you are getting erroneous NOX readings and trip codes.

I would NEVER think a code that says "nox sensor" means unequivocally that the nox sensor is bad. Never. Good guess perhaps, but not the only thing that can trip codes.

my 2 cents

[bawareca]

Originally Posted by ard

In air leak can cause odd noised under various running conditions as air if forced through a orifice (think wind instruments) ...AND...unmetered air entering the engine can ALSO cause the DDE to think you are getting erroneous NOX readings and trip codes.

I would NEVER think a code that says "nox sensor" means unequivocally that the nox sensor is bad. Never. Good guess perhaps, but not the only thing that can trip codes.

my 2 cents

I didnt hear anyone here replacing the NOX sensor. And why will both (?) fail at once?

[Dr. Anthony]

Originally Posted by bawareca

I didnt hear anyone here replacing the NOX sensor. And why will both (?) fail at once?

Originally Posted by ard

In air leak can cause odd noised under various running conditions as air if forced through a orifice (think wind instruments) ...AND...unmetered air entering the engine can ALSO cause the DDE to think you are getting erroneous NOX readings and trip codes.

I would NEVER think a code that says "nox sensor" means unequivocally that the nox sensor is bad. Never. Good guess perhaps, but not the only thing that can trip codes.

my 2 cents

You're absolutely right. I've run out of ideas so before it gets too crazy, I'm going to have a friend's indy shop take a look at it for me this afternoon.

Also, the code (3 codes) are all referring to the name nox sensor.

they are:

46B4: NOX Sensor before denox cat plausability nox.
4BB3: Nox sensor before denox cat- plausibility nox
4b6a: Nox sensor before denox cat - Plausibility

to me, I'm reading it as the nox sensor before the cat has died.

[bawareca]

"Plausibility" means that the readings of the sensor are out of the range that is stored in the DDE's maps. If someone can rust test schedules in ISTA that wive a tons of information about the problems and tips to help pinpoint the problem. I am quite sure it is not the sensor(s) itself.