[Antetokounmpo]

Originally Posted by Sgop335

As some have pointed, could be the wg solenoids. Agreed dme could be commanding them to close but they can still be open when faulty.


They need to be checked correctly,

I thought solenoids initially. But unless I was driving with only one functioning one for a while (maybe possible) I don't think they would both fail at the same time.


Side note: here is an old log from when I was consistently 1-2psi under boost.

http://www.datazap.me/u/heel-toe/log...=0&data=4-6-21

I'm not sure if that would be a cause of 1 bad solenoid. But from what I've read, it is possible.

[Antetokounmpo]

Originally Posted by vtl

What happens when you start the car up, the exhaust is loud and you hit the boost solenoid with a mallet? If your solenoids are sticky they might respond to some percussive maintenance and if hitting it works then its definitely a solenoid issue.

Also if you shut off the car after its warm and working right and start it up again, does the issue come back again for another 15 minutes of driving?

Tapped the rear with a mallet this morning. It started making the buzzing noise identical to the video below.

[vtl]

Originally Posted by Heel Toe

Tapped the rear with a mallet this morning. It started making the buzzing noise identical to the video below.

There you go, the solenoid is definitely faulty. Replace both wastegate solenoids, these things are common to fail so they should be considered normal maintenance for these cars. Also all the rubber vacuum lines should be replaced while you're in there.

Replace the pair with these:
https://www.fcpeuro.com/products/bmw...id-11747626350

[Antetokounmpo]

Originally Posted by vtl

There you go, the solenoid is definitely faulty. Replace both wastegate solenoids, these things are common to fail so they should be considered normal maintenance for these cars. Also all the rubber vacuum lines should be replaced while you're in there.

Replace the pair with these:
https://www.fcpeuro.com/products/bmw...id-11747626350

Yep, thanks for the telling me about the mallet trick. I ordered two pierburg solenoids from ecs this morning. Although that's a better price at fcp euro. Oh well

[madmantwo]

I've also been having this issue. Super loud exhaust at random points during the first 15 minutes of driving. Logged it this morning and saw 0% WGDC on bank 1 (for some reason MHD won't let me log bank 2 also..).

I had the buzzing solenoids a few months ago and replaced them both, so I doubt both of them are failing and causing my issue. I'll check it out today though.

[Antetokounmpo]

Originally Posted by madmantwo

I've also been having this issue. Super loud exhaust at random points during the first 15 minutes of driving. Logged it this morning and saw 0% WGDC on bank 1 (for some reason MHD won't let me log bank 2 also..).

I had the buzzing solenoids a few months ago and replaced them both, so I doubt both of them are failing and causing my issue. I'll check it out today though.

0% on bank 1 during WOT?

You can log bank 2 by going to logging parameters" at least I think it's called something like that

[madmantwo]

Originally Posted by Heel Toe

0% on bank 1 during WOT?

You can log bank 2 by going to logging parameters" at least I think it's called something like that

No, sorry not at WOT. Usually when I'm coasting, the wastegates are at 50% duty cycle. Periodically, they are stuck at 0%, and that is when my exhaust gets obnoxiously loud for a minute or so.

What should my WGDC be when cruising/coasting? When driving around normally, mine is at 50% when coasting and then drops to anywhere from 20-40% while giving it slight throttle. If I floor it, obviously it shoots up to near 100% momentarily to build boost. I kinda assumed 50% was a normal value for it to hover at

[cstmx_ryder]

Similar issue with under boosting. For example, my target boost is 17 psi, and the log is showing 15.xx-16.xx.....about 1-1.5 psi under the target.

Here's the kicker, I was told that that's how it's suppose to be, that the 'actual' boost will NOT be the target boost. I get that, but I'm almost certain that the actual psi shouldn't be 1.5 psi below target boost, given that everything is healthy. This MHD tune isn't the first, or second tune I've had, and this certainly ISN'T the first time reading any logs........

For example, when I was on Procede V3, the target boost and actual boost is literally side by side on the logs, varying maybe .5 psi at the max.

[Antetokounmpo]

Okay I FINALLY fixed this stupid issue. I didn't have much time to last 2 weeks to really look at it after replacing the solenoids which didn't solve the problem. (Although now I think I can confirm one of my old solenoids was bad) I was driving with 0 boost the last 2 weeks.

Tonight I had time to make up some tools to adjust the rear actuator rod. I tried to loosen the 10mm nut and it was totally rusted and I couldn't budge it. Even with 2 coats of PB blaster. I tried for a while then started playing with the rod. It felt pretty smooth and tight so I called it a night and started the car up to move it and voila, I could tell the wastegate was shut since it was much quieter now and no more rattle. Took it for a drive and it's right on target boost and spooling even better than before with the new solenoids.

http://www.datazap.me/u/heel-toe/log...a=4-6-24-29-30


I'm going to *hope* the actuator was binding or something. It felt super smooth once I start wiggling it.

I'm going to keep an eye on it this week and see if it binds again or whatever was going on. If it happens again I'll probably call my indy and see how much he'll charge to put a new actuator on. I don't have time to drop the subframe.

Originally Posted by cstmx_ryder

Similar issue with under boosting. For example, my target boost is 17 psi, and the log is showing 15.xx-16.xx.....about 1-1.5 psi under the target.

Here's the kicker, I was told that that's how it's suppose to be, that the 'actual' boost will NOT be the target boost. I get that, but I'm almost certain that the actual psi shouldn't be 1.5 psi below target boost, given that everything is healthy. This MHD tune isn't the first, or second tune I've had, and this certainly ISN'T the first time reading any logs........

For example, when I was on Procede V3, the target boost and actual boost is literally side by side on the logs, varying maybe .5 psi at the max.

See above

[ferocity02]

Originally Posted by madmantwo

I've also been having this issue. Super loud exhaust at random points during the first 15 minutes of driving. Logged it this morning and saw 0% WGDC on bank 1 (for some reason MHD won't let me log bank 2 also..).

I had the buzzing solenoids a few months ago and replaced them both, so I doubt both of them are failing and causing my issue. I'll check it out today though.

WGDC will always be the same for both banks (I think) so there is no need to log both.

Sounds like you have the same issue as me. The DME is commanding 0% WGDC and your solenoids are obeying by opening the wastegates. Therefore, this is not a solenoid issue. The OP's wastegates were stuck open even when the DME was not commanding 0% WGDC.

I still have no idea why my DME is randomly commanding 0% WGDC. It's usually while cruising, rarely during stop and go driving, although it does happen occasionally. Someone on bimmer_********** suggested it was part of the DME conducting tests of the lambda probes. I am also getting codes for one my rear O2 sensors, signal and aging. But I replaced them about 5k miles ago. I'm going to replace the front lambda probes and see if that makes any difference.

[madmantwo]

Originally Posted by ferocity02

WGDC will always be the same for both banks (I think) so there is no need to log both.

Sounds like you have the same issue as me. The DME is commanding 0% WGDC and your solenoids are obeying by opening the wastegates. Therefore, this is not a solenoid issue. The OP's wastegates were stuck open even when the DME was not commanding 0% WGDC.

I still have no idea why my DME is randomly commanding 0% WGDC. It's usually while cruising, rarely during stop and go driving, although it does happen occasionally. Someone on bimmer_********** suggested it was part of the DME conducting tests of the lambda probes. I am also getting codes for one my rear O2 sensors, signal and aging. But I replaced them about 5k miles ago. I'm going to replace the front lambda probes and see if that makes any difference.

Any update after replacing the lambda probes?

[ferocity02]

Originally Posted by madmantwo

Any update after replacing the lambda probes?

Won't have time to replace them for at least a couple weeks unfortunately.

[!LEFTCOAST!]

Originally Posted by ferocity02

Won't have time to replace them for at least a couple weeks unfortunately.

Any update? Curious to see if you resolved the issue.

[ferocity02]

Originally Posted by !LEFTCOAST!

Any update? Curious to see if you resolved the issue.

No it didn't. I replaced the lambda probes a month or so ago and that DME is still randomly commanding 0% WGDC while cruising and sometimes (rarely) in city traffic. Next step is to replace the rear O2 sensors since they are still occasionally giving me aging and signal error codes.

[b1mmr]

If I hop on the interstate after work (1 mile if that) I get random increases in volume from my exhaust as well with no effect on speed. It doesn't stay that way and I've seen it in a thread somewhere before so I basically dismissed it. I also get off at about 6am when it's the coldest.

[!LEFTCOAST!]

Originally Posted by b1mmr

If I hop on the interstate after work (1 mile if that) I get random increases in volume from my exhaust as well with no effect on speed. It doesn't stay that way and I've seen it in a thread somewhere before so I basically dismissed it. I also get off at about 6am when it's the coldest.

My exhaust randomly becomes extremely loud as well but only if I'm traveling up hill.

[b1mmr]

Originally Posted by !LEFTCOAST!

My exhaust randomly becomes extremely loud as well but only if I'm traveling up hill.

I'm not sure if the incline is relevant but I did leave work the other day and the road after pulling out of the lot is a long incline and I remember thinking to myself "damn you're loud.." I've got a muffler delete but you can def tell when the waste gates are open.

One possibility in my case could be that the car doesn't want to build boost to reduce strain on cold hardware.

Does yours do it warm? Also rattle prevention will increase the loudness.

[!LEFTCOAST!]

Originally Posted by b1mmr

I'm not sure if the incline is relevant but I did leave work the other day and the road after pulling out of the lot is a long incline and I remember thinking to myself "damn you're loud.." I've got a muffler delete but you can def tell when the waste gates are open.

One possibility in my case could be that the car doesn't want to build boost to reduce strain on cold hardware.

Does yours do it warm? Also rattle prevention will increase the loudness.

Yeah, it does it at operating temp. Running mhd but have never messed with the rattle fix option. I figured it was one or both of my wastegates giving out. I'm fully catless so it's noticeable once it happens as exhaust becomes really loud and cabin drone kicks in

[b1mmr]

Originally Posted by !LEFTCOAST!

Yeah, it does it at operating temp. Running mhd but have never messed with the rattle fix option. I figured it was one or both of my wastegates giving out. I'm fully catless so it's noticeable once it happens as exhaust becomes really loud and cabin drone kicks in

Hmm.. Mine seems fine at temp. It could be the wg but it could also be the solenoids as suggested by others.

And YEEESS.. I love my muffler delete but the open wg gets brutal at times and conversations put on pause without question. :

[Joe_435i]

Originally Posted by Harambe

Okay I FINALLY fixed this stupid issue. I didn't have much time to last 2 weeks to really look at it after replacing the solenoids which didn't solve the problem. (Although now I think I can confirm one of my old solenoids was bad) I was driving with 0 boost the last 2 weeks.

Tonight I had time to make up some tools to adjust the rear actuator rod. I tried to loosen the 10mm nut and it was totally rusted and I couldn't budge it. Even with 2 coats of PB blaster. I tried for a while then started playing with the rod. It felt pretty smooth and tight so I called it a night and started the car up to move it and voila, I could tell the wastegate was shut since it was much quieter now and no more rattle. Took it for a drive and it's right on target boost and spooling even better than before with the new solenoids.

http://www.datazap.me/u/heel-toe/log...a=4-6-24-29-30


I'm going to *hope* the actuator was binding or something. It felt super smooth once I start wiggling it.

I'm going to keep an eye on it this week and see if it binds again or whatever was going on. If it happens again I'll probably call my indy and see how much he'll charge to put a new actuator on. I don't have time to drop the subframe.





See above

Did this completely resolve your issue? My car is doing the same thing and wanted to know if I should start with the rear actuator.

After doing some reading it could be three issues.
1. sticky waste gates
2. rear actuator needs adjusting/lube
3. Boost solenoids

I don't have any codes and my turbos are 1.5 years old. I do notice the WGDC drop to 0% more often when it's colder outside. It mostly does it on the freeway while cruising.

[madmantwo]

I just had my turbos replaced and I no longer have the issue FWIW.

[Joe_435i]

Originally Posted by madmantwo

I just had my turbos replaced and I no longer have the issue FWIW.

Nice! Did you get your turbos replaced because of rattle or another issue?