Strange hum from intake

Ruster82 · 04-29-2021, 07:16 AM

I have got a 2006 335i E92, the only modifications it has are DCI and a remap.

After driving and coming to traffic lights or parking up I can hear a loud hum coming from the rear intake cone.

Anyone had this before or have any idea what it could be?

My best guess atm is the PCV system is struggling which is why I can hear it through the rear cone (the one the PCV pipe from the valve cover connects) and seems to be after boosting mostly

I only started hearing this today and will try and get a video uploaded to help with suggestions but for now anyone have an idea?

Ruster82 · 04-29-2021, 07:17 AM

I forgot to add the car has done 92000 miles

lookalikehuuh · 04-29-2021, 10:19 AM

Do you have a video of the sound?

Ruster82 · 04-29-2021, 12:35 PM

Yes I took one as soon as I got home:

https://streamable.com/wc6x1l

Dave92N54 · 04-29-2021, 01:18 PM

Definitely sounds like it's coming from the rear inlet or that area. Check to make sure the inlet is still connected to the turbo, the rear is known to pop off or even crack where they connect to the turbo.

lookalikehuuh · 04-29-2021, 01:33 PM

That sounds extremely similar to when the PCV fails so I think your suspicions of it coming from that pcv pipe is correct.

Ruster82 · 04-29-2021, 01:44 PM

Thank you both for the input, I will take a closer look over the weekend, weather permiting.

If it turns out to be the pcv pipe has anyone had one apart to see whats inside I guess a one way valve that could be clogged

Bimmer_Bro · 04-29-2021, 03:59 PM

Quote:

Originally Posted by Ruster82

Thank you both for the input, I will take a closer look over the weekend, weather permiting.

If it turns out to be the pcv pipe has anyone had one apart to see whats inside I guess a one way valve that could be clogged

Just buy the RB turbo pcv valve or the bms one. Both a upgrade over stock. Very simple to install. I'm sure the piping going from the check valve to the rear inlet is fine. You would get a oil drip if it was cracked. I'd Replace the valve and go from there

Ruster82 · 04-30-2021, 12:38 PM

I have already replaced the PCV valve with an upgraded one a while ago but thank you for the suggestion.

I haven't had a chance to have a proper look yet but today it didnt make a sound so might be a bit difficult to track.

There is a secondary PCV built into the valve cover if I read a post correctly when I first started looking into the PCV system, If it's not the pipe going from valve cover to intake pipe then possibly time to change the valve cover

04-29-2021, 07:16 AM	#1
Ruster82 Private 28 Rep 96 Posts Drives: 2011 320d Efficient Dynamics Join Date: Aug 2020 Location: Devon, UK iTrader: (0)	Strange hum from intake I have got a 2006 335i E92, the only modifications it has are DCI and a remap. After driving and coming to traffic lights or parking up I can hear a loud hum coming from the rear intake cone. Anyone had this before or have any idea what it could be? My best guess atm is the PCV system is struggling which is why I can hear it through the rear cone (the one the PCV pipe from the valve cover connects) and seems to be after boosting mostly I only started hearing this today and will try and get a video uploaded to help with suggestions but for now anyone have an idea?
	Appreciate 1 Bimmer_Bro393.00 Tweet Quote

04-29-2021, 07:17 AM	#2
Ruster82 Private 28 Rep 96 Posts Drives: 2011 320d Efficient Dynamics Join Date: Aug 2020 Location: Devon, UK iTrader: (0)	I forgot to add the car has done 92000 miles
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04-29-2021, 10:19 AM	#3
lookalikehuuh Major 700 Rep 1,229 Posts Drives: 2006 330i, 2007 335i Join Date: Sep 2014 Location: San Diego, CA iTrader: (0)	Do you have a video of the sound?
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04-29-2021, 12:35 PM	#4
Ruster82 Private 28 Rep 96 Posts Drives: 2011 320d Efficient Dynamics Join Date: Aug 2020 Location: Devon, UK iTrader: (0)	Yes I took one as soon as I got home: https://streamable.com/wc6x1l
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04-29-2021, 01:18 PM	#5
Dave92N54 Major 528 Rep 1,165 Posts Drives: 09 E92 335i 6MT Join Date: Nov 2020 Location: Westminster, Maryland iTrader: (0) Garage List 2009 BMW 335i [10.00]	Definitely sounds like it's coming from the rear inlet or that area. Check to make sure the inlet is still connected to the turbo, the rear is known to pop off or even crack where they connect to the turbo. __________________ 09 E92 335i 6MT / Alpine White / Coral Red / VRSF 7.5" / VRSF DCI / VRSF Catless Downpipes / VTT Charge Pipe / Turbosmart RacePort Gen V / RB OEM Billet Turbos / CD919 Custom Tune / Bilstein PSS9s
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04-29-2021, 01:33 PM	#6
lookalikehuuh Major 700 Rep 1,229 Posts Drives: 2006 330i, 2007 335i Join Date: Sep 2014 Location: San Diego, CA iTrader: (0)	That sounds extremely similar to when the PCV fails so I think your suspicions of it coming from that pcv pipe is correct.
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04-29-2021, 01:44 PM	#7
Ruster82 Private 28 Rep 96 Posts Drives: 2011 320d Efficient Dynamics Join Date: Aug 2020 Location: Devon, UK iTrader: (0)	Thank you both for the input, I will take a closer look over the weekend, weather permiting. If it turns out to be the pcv pipe has anyone had one apart to see whats inside I guess a one way valve that could be clogged
	Appreciate 1 Dave92N54528.00 Quote

04-30-2021, 12:38 PM	#9
Ruster82 Private 28 Rep 96 Posts Drives: 2011 320d Efficient Dynamics Join Date: Aug 2020 Location: Devon, UK iTrader: (0)	I have already replaced the PCV valve with an upgraded one a while ago but thank you for the suggestion. I haven't had a chance to have a proper look yet but today it didnt make a sound so might be a bit difficult to track. There is a secondary PCV built into the valve cover if I read a post correctly when I first started looking into the PCV system, If it's not the pipe going from valve cover to intake pipe then possibly time to change the valve cover
	Appreciate 0 Quote