X5 diesel engine noise - With VID.
 

Hi guys. I don't post much on here, but do browse/lurk.

I have a 2009 X5 diesel and I'm trying to diagnose a noise. It sounds like a screeching.. loud scream. I've posted a video and was wondering if someone has heard this before. I've been searching all week and have yet to find something similar. Sorry for the poor quality video, but it's all I could come up with.

any help is greatly appreciated.
the engine light is related to nox sensor replacement.
currently have 210,000 km (130k miles)

https://www.youtube.com/watch?v=PclB_FxEEPM


***EDIT****
Alright, so I thought I would give an update to my issue. Long story short, its not solved yet. But here's what we did do.


Did a smoke test. Everything was good, except... where the wastegate is on the lower turbo. That's where you can see some soot escaping.. So the wastegate bushings/seals are gone.. and Looks like i'll need to pull the turbo off to get it rebuilt or swapped out.

I feel a bit of play. if I hold it closed, the noise goes away. Obviously I don't want to do this long term. I just wanted to see if I could replicate the noise while holding pressure on the wastegate so it doesn't move. Noise could NOT be replicated.

I also scanned for codes with a different machine and was able to get a few more out of it. I'll update the 1st post to show these for others searching.

they are:



4BB3: Nox sensor before denox cat- plausibility nox
4b6a: Nox sensor before denox cat - Plausibility
46B4: NOX Sensor before denox cat plausability nox.
4C04 - I think this could be EGT temp is too high (non-plausible)
4D16 - SCR system, efficiency: Efficiency too low
46A4 - NOx sensor after DeNOx cat., plausibility NOx: NOx signal offset too high at trailing throttle

Bearing or belt. For instance, (water) pump load rises by the square of speed, and your squeak happens at the highest rpm.

How's the tensioner?

Thanks for the reply, I don't think its the belt. (I could be wrong) I feel that its more based on load vs RPM too. At first I thought it was turbo bearing related, but the more i think about it, the more it leads me to believe it isn't. I haven't checked the tensioners. I suppose I could always do that. I would think that if it were the tensioners it would be through most RPM range?

if I drive around normally, (without spirited accelerating) the noise won't come on. You only hear it with a bit of load.

example; I drove to the opposite side of the city yesterday (40-50k round trip) and never once heard it.

Also, depending on load, that screech sound could happen on the lower RPM range. at first I thought it was the small turbo as it went away at 2,000 rpm. but the more I played around with it, I realized it was more dependent on load vs rpm.

Sounds like a turbo issue. Let us know what you learn. Taking it to an experienced indy?

I'm pretty mechanically inclined, I'd probably swap it myself. I just want to narrow it down before I rip it apart.

OK, well you have my best guess, just based on the video. What are the rpms when you detect that "screech". To me it has a metal on metal sound quality. Turbo bearings? I have not experienced a failure with this sound signature.

at first it was upto 2000, but yesterday when I took the video and tried to replicate the sound I noticed it would still do it on higher RPM. I *believe* the small turbo is upto 2000 RPM, and that's when the larger turbo kicks in. I could be wrong tho. That's why originally, I thought it was a high pressure (small turbo) bearing issue.

I'm hoping it's not a turbo issue as I'd probably want to replace both. (if 1 is failing, the other may not be too far behind) which would be quite the job. Replacing the lower turbo looks like 15hr book time for labour. 4.x hours for the small turbo. + the cost for all the parts.

When it does squeel, its only for a second or 2 as you can hear in the vid.

Just a guess but it sounds like a valve whistling. Do these things have bypass valves on the turbos?

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.

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.

According to OP it's because of the NOx sensors

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.

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.

:thanks:

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.

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

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

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.

"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.

wow, good to know. I believe the sensors were already replaced a couple of years ago too. I can't get inpa/ista working properly on my laptop. I'll see if I can get a friend to check that out for me. I appreciate your help.

Sure, keep us posted.
I have new versions ISTA/D standalone for WIN7,8 and I can install remotely. The ICOMs are down to under $200 now so a pretty decent system can be had for almost nothing.

The laptop I use for that is an old windows laptop that I have the bavtech installed on. If you have links to something, I'd definitely consider buying a new setup if I knew i could get it working :)

The only thing I use the inpa cables for now (I have 2) is to register batteries, and clear codes using bmwlogger on my mac.

Either way, I'll definitely update the thread as I get more info and hopefully resolve it.

I had a 4BB2: SES/CEL: Code 4BB2....Anyone else? - Bimmerfest - BMW Forums

http://www.xoutpost.com/846433-post20.html

Lemoned that car in 2011.

'Code' does not equal 'part'. These cars use the values from the sensor and how they respond after the DDE adjusts other control parameters to trap errors. It may be the sensor is bad, but far more likely it just isnt responding the way engineering said it should (and the DDE expects). You can have a clogged SCR orifice, bad metering value, bad SCR cat, etc, etc. You need to run test plans.


Good luck. This stuff is a PITA.

(Ive just posted my crap to give you a sense of a bad story- lets hope yours is more straightforward.)

I sent you a PM. I have Rheingold (and DIS) both working with a 20 bucks connector from Amazon -> Amazon.com: KCRIUS(TM) K+D CAN USB Interface OBD2 Cable Diagnostic Scanner for BMW only: Automotive

All running on a WindowsXP Centrino Sonoma laptop.

I don't think it gets any cheaper...

Thanks for the info guys.

Just a bit of an update. I brought it by my friend's shop. We took it for a test drive. It was hard to replicate. (of course) However, we did a bit of a stress test by holding the brake and trying to build some boost stationary. (yep, I know this is hard on the transmission) From that (also had 2 techs listen for it) it sounds like a boost leak somewhere.


We did notice some soot buildup around the bypass valve, and also some soot where the pipe goes into what looks like throttle (is this normal?)

Alright, so I thought I would give an update to my issue. Long story short, its not solved yet. But here's what we did do.


Did a smoke test. Everything was good, except... where the wastegate is on the lower turbo. That's where you can see some soot escaping.. So the wastegate bushings/seals are gone.. and Looks like i'll need to pull the turbo off to get it rebuilt or swapped out.

I feel a bit of play. if I hold it closed, the noise goes away. Obviously I don't want to do this long term. I just wanted to see if I could replicate the noise while holding pressure on the wastegate so it doesn't move. Noise could NOT be replicated.

I also scanned for codes with a different machine and was able to get a few more out of it. I'll update the 1st post to show these for others searching.

they are:


4BB3: Nox sensor before denox cat- plausibility nox
4b6a: Nox sensor before denox cat - Plausibility
46B4: NOX Sensor before denox cat plausability nox.
4C04 - I think this could be EGT temp is too high (non-plausible)
4D16 - SCR system, efficiency: Efficiency too low
46A4 - NOx sensor after DeNOx cat., plausibility NOx: NOx signal offset too high at trailing throttle

Whats the latest with your X?
I have the same issue/noise so I pulled the inlet air tubes on low pressure turbo (lower big turbo) and the high pressure Turbo (top turbo) to check for shaft play. lower turbo is fine, but the top turbo has play in the shaft which is causing the compressor wheel to rub under full boost. I am in the process of finding a replacement CHRA (center section of turbo) or a rebuilt turbo and have been told buy 2 rebuilders who spoke to Borg Warner that it is a dealer only item.
I am not convinced that that is the case as B/W is having them rebuilt so they must be available unless they are rebuilding it themselves.
Has anyone had luck finding a replacement unit other then through BMW? My turbo part number is 5439 971 0088 (BorgWarner KP39-1873ECD310.12ACCXX) BMW part #11657811405.

So here's your update... My sound got worse as I put more mileage on the vehicle.

I thought it was my turbos. I bought bohl turbos and had them installed at a shop as I didn't have the time and just wanted it "done" The day it was supposed to be done, the guy calls me and says "There's a manifold stud/bolt on your head thats broken" I asked him to remove it, drill it out.. whatever, just get it done. (I had supplied all new gaskets, bolts, o-rings..etc) He claimed he wasn't able to, but said "it'll be fine.." He bolted it all back together with the new turbos, new seals around all the charge pipes, and a new red chargepipe. He also couldnt find my supplied gaskets that are used for the turbo to the manifold. So he reused my old gaskets. Anyways, he Started it up and got the EXACT SAME SOUND.
Except now, its worse. I should have just done it myself. Anyway, it'll be torn down next week and if I have to rip the head off to have it drilled out, so be it. I'll use all brand new gaskets as well for obvious reasons. But I honestly feel the noise I'm getting is definitely from these gaskets.

my old turbos had some play, but nothing significant. Again, none of the impellers were rubbing against the housing tho.
Hope this helps

TLDR: Replaced turbos, it wasn't the turbos.

I have discussed this matters with some friends in Europe and turbo problems on a BMW diesels are almost unheard of. Even after upping the stock power 60-70%. And if a turbo wheel rubs against the housing it will be gone in a short time.

Ouch, That sucks! Good luck with it and thanks for the update.

Sure hope you didn't pay for someone to put it back together broken! If he couldn't get the stud out, why didn't he stop and find someone who could?

Bet that's your issue though, it sounds like a vac/pressure type noise that'd get louder with increased manifold pressure (increased load/RPMs). If you had an internal turbo issue you likely wouldn't hear it AND your turbo would be smoked quick. Don't forget those things spin at 25,000+ RPMs.

Sounds like the shop tried to say 'stop', OP insisted 'just get it done' and the shop finally relented and said 'yeah, it should be OK'.

Bit of a cluster IMO. People complain about dealers throwing parts at the issue....

:(

My d sounded very similar to yours when several of the exhaust manifold nuts were loose. That was at 52k. Tightened them up and the sound stopped.

A bit of a long shot, but defective vibration damper (=crankshaft pulley) can cause similar squeaking. To check its state, you have to use a flat screwdriver as visually you can't really spot it splitting until it falls apart completely.

Yep, that is becoming more common with mileage or mods.

BTW, some soot on/around turbos is OK, I believe there's even an tech.article from BMW about it.

You sure like chiming in on threads with your negative nonsense don't you?
Where did I say the shop said "lets stop" and I said "no, lets continue"

I see you continually replying to threads with your smart remarks, yet offer nothing.

A+ :thumbup:

I never knew that was an issue. I'll take a look and see next week.
Thanks for the info

I took a video of the high pressure turbo for our viewing pleasure.
https://youtu.be/2oQgK-6g3O0

I would say thats quite a bit of play. My stock ones had no where near that amount of play

Ok, thx, I thought that might be the case, I'm surprised it's not making more noise then what it is. Looks like I'm going to have to bite the bullet and get it from BMW since I can't find a quality rebuilt one. Plus if I get it from BMW it has a 2 year warranty I believe?

I have a contact for you. He's in new york, so depending how far that is from you, he could probably even do the swap for you.

Give Jess a call at Bohl Diesel. He's the one who built my new turbos. You can even upgrade them if you're looking to make more power. I opted for stock-ish replacements.

He's quite knowledgeable as well.

BMW — Bohl Diesel Performance
(518) 859-2351

Thank you for the contact Dr Anthony. I live in the Chicago area and enjoy doing the work, but I will definitely give him a call. Assuming he has your old core perhaps he can rebuild that and ship it to me then I send him my core so my X is not down long.

I'm sure he has some cores that he can build for you.
I ended up paying extra to keep mine, and I'm glad I did since there was nothing wrong with them.

Sounds good, I'll give him a call tomorrow.

So have you found out what was/is(?) causing the noise? I know of a similar case and wonder if it's possible to remove both belts for a quick ride to rule out the pulley.

Did you resolve your issue? I still have the same noise as you and want to get it resolved.

I did. turns out my turbos were perfectly fine :/ Oh well, atleast now i have a spare set of turbos. Anyways, my issue was the exhaust manifold gasket.
one of my studs broke. (previous dealer repair) and the air was escaping between the flange and the gasket. It totally makes sense tho. The gasket is 5 thin pieces of metal.

Remember the sound you'd make when you put a thick blade of grass between your thumbs and blew through it? Same concept.. similar sound.

Interesting, that does make sense. Was it the top turbo to manifold gasket or manifold to head gasket? i ask because i pulled my small turbo off today to send it to Tims Turbo (whom i believe rebuilt yours for Bohls, but i could be wrong, too many turbo conversations lately) and i noticed the bolts where not as tight as i expected them to be, not loose but easily broke free. i also notice there was soot under the gasket, which means a leak.
Thank you very much for the feedback!

Mine was right at the head. one of the studs had broken off. It was the one closest to the front of the motor. on the top right. I spent a lot of money trying to nail it down. Hope it helps!

That helps a lot! thanks.

Good luck! let me know how it goes.

Will do.

I seem to have a leak.I see soot in picture that I'll post.It has a mild exhaust leak sound at speed.It might be hard to see,it's all around where that wire goes in.Any ideas?
https://postimg.org/image/s4hkivwnn/
My iPad doesn't post pictures on forums now for a few years.

That leak is from the bypass actuator rod due to the cast iron wearing with use. (they should have put a replaceable bushing in there). mine is doing that and the other used 35ds i have seen are also doing it. i have not heard if there is a fix for it other than replacing the turbo.

Thanks.Is that something that would be under warenty? I just looked and there is soot leak at bypass bushing.

OK, So its resolved! well more or less.. With the small turbo off I was able to see the top stud on #1 cylinder was broken off! i spent the day yesterday drilling and tapping it (after buying a 90deg air drill small enough to get in there, nice drill bits and a set of easy-outs of course) once that was done i decided to check the bottom stud on #1 and when i tried to see if it was tight by applying maybe 5lbs of pressure it fell right out, broken off in the head. The top bolt pulled the manifold tight the head nicely and hopefully will do its job and keep it there so i don't have to replace the lower stud,
the noise is gone and it seams to have more boost since its not blowing out the manifold.
I bought this 09 X5 used and per the service records BMW was the only one working on it before i bought it with 74k miles. No mention of them working on or near the exhaust manifold other then replacing the DPF, EGR cooler and SCR which they don't need to remove the manifold for that so not sure if the studs just fatigued over time and snapped maybe due to the manifold twisting or such or that a mechanic took it off for some other reason and over torqued them.

Thanks again for the help!

Not sure, I bought mine used with no warranty so i never checked.

It's great you guy have it all sorted now! I'm doing a 2 tank trip to a dealer I know will sort it out for me.Local shop straight ( doesn't want to mess with it) out doesn't see what's wrong.Says it's perfect .lol Thanks for your help !

If you are in California OR A STATE THAT FOLLOWS CA EMISSIONS WARRANTY, there is a 7 year 70k warranty on the Turbo.

It is shocking how many people do not appreciate these warranties (and BMWs ability to goodwill if just outside)