[cn555ic]

I just started the car and the boost solenoid towards the front of the engine made this weird ass sound like it was cycling on and off and couldn't close or open to the position it is suppose to be when idling...Very weird...It cycled on and off like it was jammed for like 15 seconds...I turned the car off and then started it again, and it still made the noise again...I went to the Procede to clear all the adaptations from 11-1 and then restarted the car...Upon startup the boost solenoid made the cycle on and off for like 2 seconds and then it went away..I am stumped...What do you guys think? I dont want to drive the car if there is something wrong...What does a non functioning boost solenoid do to a car if its not working properly?? I guess i am only boosting with one turbo if thats the case!

[OpenFlash]

Nothing is wrong with the solenoid. They can make funny buzzing noises from time to time. As long as the car is driving/boosting normally, go about your business. Each solenoid doesn't control each turbo. They both work together to control both turbos at the same time. If a solenoid where to fail, you wouldn't make full boost and trigger underboost codes.

Shiv

[cn555ic]

Originally Posted by shiv@vishnu

Nothing is wrong with the solenoid. They can make funny buzzing noises from time to time. As long as the car is driving/boosting normally, go about your business. Each solenoid doesn't control each turbo. They both work together to control both turbos at the same time. If a solenoid where to fail, you wouldn't make full boost and trigger underboost codes.

Shiv

Thanks SHiv...but it was so loud that it rattled the hood...Thats how I noticed it...It was very weird...If it happens tomorrow, I will take a video of the noise, I have never heard this noise come out of those solenoids before!

[OpenFlash]

Originally Posted by cn555ic

Thanks SHiv...but it was so loud that it rattled the hood...Thats how I noticed it...It was very weird...If it happens tomorrow, I will take a video of the noise, I have never heard this noise come out of those solenoids before!

When it happens, drive your car to see if boost is controlled normally.

Shiv

[scott135i]

DID IT SOUND LIKE THIS? I recorded this today on my mother's car... 2008 135i... same thing happened 2-3 weeks ago, but it went away...

And this is it happening a few weeks ago:

[cn555ic]

Originally Posted by scott135i

DID IT SOUND LIKE THIS? I recorded this today on my mother's car... 2008 135i... same thing happened 2-3 weeks ago, but it went away...

And this is it happening a few weeks ago:

Yes thats the same exact noise and the same location! Shiv what do you think of the video? I will look at the boost tomorrow closely to see what it logs...Just very strange.

[scott135i]

Car that it's happening on is stock at the moment, but is running PERFECTLY. Once tuned I'll check again. No codes, and feels strong. VERY WEIRD.

[cn555ic]

Originally Posted by scott135i

Car that it's happening on is stock at the moment, but is running PERFECTLY. Once tuned I'll check again. No codes, and feels strong. VERY WEIRD.

Yeah I never heard this sound ever and it was so loud that it made my hood rattle to the point that I noticed it and opened the hood....I restarted the car 3 times and use a piece of wood to gently give it a bang...On the 3 start of the car it sounded for 2 seconds and then went away...This was inside my garage and I have not taken the car after the noise went away..Cant take it out as when I start my car it wakes up my newborn son!
Have to check tomorrow and like Shiv stated look to see if the car is boosting correctly...I still dont think its normal and swapping out that solenoid doesn't look to be hard at all...

[michaelalex17]

that sounds odd

[cn555ic]

Originally Posted by michaelalex17

that sounds odd

Yeah tell me about it! WEIRD...but to me it sounds like the solenoid is jammed when it makes this noise, and wont open or close to the position it wants to...I will check again tomorrow and try to diagnose it better...Too dark in my garage and cold..

[OpenFlash]

Originally Posted by cn555ic

Yes thats the same exact noise and the same location! Shiv what do you think of the video? I will look at the boost tomorrow closely to see what it logs...Just very strange.

Since it happens to stock/no tune cars, it has to be hardware related. Maybe caused by some foreign material caught in the solenoid. I've heard that sound before one some cars so it's nothing to be worried about IMHO. If it bothers you or becomes more persistent, take it to the dealership and let them investigate.

[chappy]

Yes my rear pressure converter buzzes as well from time to time with the new 3-15 maps not the 2-14 maps shiv emailed me and i will upload back to the 3-15 maps again and shiv said to lower the wastegate value a little,so i will try that tomorrow night to see if it works, or i don't worry about it or just go back to the 2-14 maps which are very very good and smooth.

Shiv thanks very much for your quick response much appreciated,

[michaelalex17]

Originally Posted by shiv@vishnu

Since it happens to stock/no tune cars, it has to be hardware related. Maybe caused by some foreign material caught in the solenoid. I've heard that sound before one some cars so it's nothing to be worried about IMHO. If it bothers you or becomes more persistent, take it to the dealership and let them investigate.

+1 since it happens on stock cars, i'd take it to the dealer.

[joec500]

+1 been happening on my car for the last 30k+ miles, I just thought it was pressure building in the system.

[scalbert]

To me that sounds pressure, or rather, vacuum related. I would check to see if it drives normally as it may be just a sound that occurs at a certain duty cycle and vacuum level; hitting a certain harmonic causing something to resonate.

[OpenFlash]

Originally Posted by scalbert

To me that sounds pressure, or rather, vacuum related. I would check to see if it drives normally as it may be just a sound that occurs at a certain duty cycle and vacuum level; hitting a certain harmonic causing something to resonate.

+1 I've always dismissed it as an harmonic. Which makes sense since you can change/elminate the sound by changing the DC o solenoids. And since different DME versions run the solenoids at different DC at idle, you are going to see some cars making that sound while others aren't.

Shiv

[cn555ic]

Originally Posted by shiv@vishnu

+1 I've always dismissed it as an harmonic. Which makes sense since you can change/elminate the sound by changing the DC o solenoids. And since different DME versions run the solenoids at different DC at idle, you are going to see some cars making that sound while others aren't.

Shiv

I dont know....just went out with the car and when the engine bay is relatively cold the solenoid doesn't act up and the first couple of runs the solenoid near the rear of the engine doesn't make this strange noise...When it doesn't make this noise the boost hit its targets....Once the engine and that area get really hot (under the DPs) it starts making that noise again and I cannot hit the 15.5 psi and its only getting me around 11-12 psi....I am going out again later and check this out again once the engine is fully cooled....To me its not normal and the sound coming from it is not a moan but something that seems to be jammed....Like a circuit trying to repeatedly open a stuck valve noise....What does that solenoid actually do and if one is bad would it not allow a car to boost what the target is? I already looked into a replacement as its seems not hard to change out..part number is 11747595374 at realoemparts.com

[themyst]

Originally Posted by cn555ic

I dont know....just went out with the car and when the engine bay is relatively cold the solenoid doesn't act up and the first couple of runs the solenoid near the rear of the engine doesn't make this strange noise...When it doesn't make this noise the boost hit its targets....Once the engine and that area get really hot (under the DPs) it starts making that noise again and I cannot hit the 15.5 psi and its only getting me around 11-12 psi....I am going out again later and check this out again once the engine is fully cooled....To me its not normal and the sound coming from it is not a moan but something that seems to be jammed....Like a circuit trying to repeatedly open a stuck valve noise....What does that solenoid actually do and if one is bad would it not allow a car to boost what the target is? I already looked into a replacement as its seems not hard to change out..part number is 11747595374 at realoemparts.com

My 135i made the noise scott135s videos show, wastegate solenoid failed. But Shiv's right, if it fails it will throw underboost codes, like my 135i did stock. Dealer took care of it.

[cn555ic]

No codes at all. That's the weird part. The noise is not coming from the wastegate solenoid but 100% positive it's coming from the rear boost pressure solenoid. The one closest to the front of the car doesn't make this cycling noise at all

[cn555ic]

I just checked the vacuum tubing that goes from the vaccum tank to the solenoid thats making the noise...I am not sure but it looks like the tubing seems to be hitting my RR catch can bottom portion and seems to have either melted some of it away or from abrasion...I cant see if there is a pin-hole around that area but I do see that a portion has been sheared away from either the high temps of the can or from years of rubbing...I am going to change out that vacuum tube and see if that cures the noise....I have to let the engine cool down totally to get into that area...Too damn hot..Keep you guys posted

This week has not been a good week...Find out positive terminal was not tightened enough which was the reason for my ABS malfunction warning and the interior lights dimming!! lol The switch to my meth kit went bad....cheap ass switch, and now this issue with this rear boost solenoid! Before all this the car was running stronger than ever!

It has to be either a bad boost pressure solenoid or this vacuum tubing that is leaking...

[Jeff@TopGearSolutions]

I got the same exact noise... heard it yeterday.

Tried to get it on video but it went away as soon as I did.

It didnt happen till 3-15 update

It sounds like there was a vacuum cleaner going across the rug near my turbo's.

Seriously...

I have a RR Catch can too

[Jeff@TopGearSolutions]

Originally Posted by scott135i

DID IT SOUND LIKE THIS? I recorded this today on my mother's car... 2008 135i... same thing happened 2-3 weeks ago, but it went away...

And this is it happening a few weeks ago:

YES thats what mine was doing!

Is everyone on the latest software update? Cause it also happened after that too.