Boost Solenoid Failing Prematurely?

ferocity02 · 10-23-2015, 01:36 PM

A few months ago I had this very loud tapping sound at idle happen to me and was told it was a boost solenoid (they had about 88k miles on them). While it was tapping I lightly hit each boost solenoid with a screwdriver, and one hit to the front solenoid and the tapping instantly stopped.

So I replaced both solenoids with Pierburg solenoids from ECS Tuning. The tapping went away for a few months but came back this week about 1000 miles later. Again, while it was tapping, I lightly smacked both solenoids with a screwdriver and the tapping stopped instantly once I hit the rear solenoid.

Why are these failing so often? I was thinking that it could be related to setting the MHD wategate rattle setting to 0% which keeps the gates open on decel. I'm also running the E40 map which target 21+ psi. Perhaps these settings are stressing the solenoids too much?

ECS is sending me a replacement since they are still under warranty.

Here is a video of the tapping, tapping starts at 29s:

Sgop335 · 10-23-2015, 06:59 PM

Not sure if your solenoids failed. Have you checked their opeartion with a vacuum gage, say at idle? Also, i dont think they see any boost so 21 psi shouldnt matter. Their only purpose is to open or close the wg with vacuum.

terryd5150 · 10-24-2015, 05:17 PM

Have you replaced all the vacuum lines and checked the reservoirs for cracking around the inlets & outlets?

ferocity02 · 10-24-2015, 09:51 PM

Yes all lines were replaced about 5k ago and the reservoirs are fine. It's definitely the boost solenoid.

Just curious why it failed so quickly. Could be coincidence I guess. I'll replace it and see how long it lasts but I'm wondering if it's getting stressed too much (exceeding duty cycle for example) by forcing the wastegates full open the majority of the time.

PNWN54 · 10-25-2015, 12:00 PM

I get the same kind of noise periodically as well. Were you having any symptoms of boost leak?Have you noticed any performance difference with replacing boost solenoids? Also running Wedge E40 tune.

ferocity02 · 10-25-2015, 03:41 PM

Quote:

Originally Posted by Rock&Roll

I get the same kind of noise periodically as well. Were you having any symptoms of boost leak?Have you noticed any performance difference with replacing boost solenoids? Also running Wedge E40 tune.

No noticeable difference after replacing the solenoids, just no tapping sound. No boost leaks, I checked.

N54Society · 12-16-2015, 05:44 PM

Quote:

Originally Posted by ferocity02

No noticeable difference after replacing the solenoids, just no tapping sound. No boost leaks, I checked.

Has the noise returned? I'm thinking I need to replace mine as well.

ferocity02 · 12-16-2015, 06:33 PM

Quote:

Originally Posted by vbp6us

Has the noise returned? I'm thinking I need to replace mine as well.

That sounds awful! Have you tried smacking the boost solenoids like I did?

I have not replaced the possibly-faulty solenoid since creating this thread. The tapping sound has not come back. I should replace it though before the warranty on the part expires.

10-23-2015, 01:36 PM	#1
ferocity02 Colonel 530 Rep 2,083 Posts Drives: 2013 135is Join Date: May 2014 Location: USA iTrader: (8)	Boost Solenoid Failing Prematurely? A few months ago I had this very loud tapping sound at idle happen to me and was told it was a boost solenoid (they had about 88k miles on them). While it was tapping I lightly hit each boost solenoid with a screwdriver, and one hit to the front solenoid and the tapping instantly stopped. So I replaced both solenoids with Pierburg solenoids from ECS Tuning. The tapping went away for a few months but came back this week about 1000 miles later. Again, while it was tapping, I lightly smacked both solenoids with a screwdriver and the tapping stopped instantly once I hit the rear solenoid. Why are these failing so often? I was thinking that it could be related to setting the MHD wategate rattle setting to 0% which keeps the gates open on decel. I'm also running the E40 map which target 21+ psi. Perhaps these settings are stressing the solenoids too much? ECS is sending me a replacement since they are still under warranty. Here is a video of the tapping, tapping starts at 29s: __________________ 2013 135is DCT Carbon Black Metallic
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10-23-2015, 06:59 PM	#2
Sgop335 Colonel 648 Rep 2,013 Posts Drives: 07 335i e92, 08 535i Join Date: Jun 2014 Location: MD iTrader: (1)	Not sure if your solenoids failed. Have you checked their opeartion with a vacuum gage, say at idle? Also, i dont think they see any boost so 21 psi shouldnt matter. Their only purpose is to open or close the wg with vacuum. __________________ 335i e92 TPC 19Ts
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10-24-2015, 05:17 PM	#3
terryd5150 Head Fry Cook at McBurgertown 507 Rep 1,005 Posts Drives: 2015 435i M-Sport 6MT Join Date: May 2015 Location: Greenville, SC iTrader: (9)	Have you replaced all the vacuum lines and checked the reservoirs for cracking around the inlets & outlets?
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10-24-2015, 09:51 PM	#4
ferocity02 Colonel 530 Rep 2,083 Posts Drives: 2013 135is Join Date: May 2014 Location: USA iTrader: (8)	Yes all lines were replaced about 5k ago and the reservoirs are fine. It's definitely the boost solenoid. Just curious why it failed so quickly. Could be coincidence I guess. I'll replace it and see how long it lasts but I'm wondering if it's getting stressed too much (exceeding duty cycle for example) by forcing the wastegates full open the majority of the time.
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10-25-2015, 12:00 PM	#5
PNWN54 MR. Rocket 46 Rep 398 Posts Drives: 2010 E92 335i M-Sport Join Date: May 2013 Location: Portland, OR iTrader: (2) Garage List 2010 E92 BMW 335i [0.00]	I get the same kind of noise periodically as well. Were you having any symptoms of boost leak?Have you noticed any performance difference with replacing boost solenoids? Also running Wedge E40 tune.
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