Intermittent PCV Squeal

andykrow · 08-25-2023, 03:55 PM

I have a 2011 335i, it's intermittently giving out the crazy squeal that seems to be associated with the PCV valve failure. When it happens it goes away when I pull the oil cap off.

Strangely, this doesn't happen all the time. It's usually at the startup idle when the car is already warm, and generally completely goes away after driving it for half a block or less.

Are there causes other than the PCV for this noise? Any thoughts on why it would be intermittent?

Thanks in advance!

whyzee125 · 08-26-2023, 11:31 AM

Your PCV is failing but it's not 100% blocked yet. You need a new valve cover. Very common on N55's.

andykrow · 08-28-2023, 02:21 PM

Is this the same as replacing the little PCV diaphragm thing? (When the rubber diaphragm gets a tear)

Or does the valve cover have other components of the PCV system that can fail?

08-25-2023, 03:55 PM	#1
andykrow Enlisted Member 6 Rep 42 Posts Drives: 2011 BMW 335xi Join Date: Nov 2020 Location: Steamboat Springs, CO iTrader: (0)	Intermittent PCV Squeal I have a 2011 335i, it's intermittently giving out the crazy squeal that seems to be associated with the PCV valve failure. When it happens it goes away when I pull the oil cap off. Strangely, this doesn't happen all the time. It's usually at the startup idle when the car is already warm, and generally completely goes away after driving it for half a block or less. Are there causes other than the PCV for this noise? Any thoughts on why it would be intermittent? Thanks in advance!
	Appreciate 0 Tweet Quote

08-26-2023, 11:31 AM	#2
whyzee125 Brigadier General 1680 Rep 3,645 Posts Drives: Dinan stage 2 335i Join Date: Jul 2014 Location: Chattanooga Tn iTrader: (0)	Your PCV is failing but it's not 100% blocked yet. You need a new valve cover. Very common on N55's.
	Appreciate 0 Quote

08-28-2023, 02:21 PM	#3
andykrow Enlisted Member 6 Rep 42 Posts Drives: 2011 BMW 335xi Join Date: Nov 2020 Location: Steamboat Springs, CO iTrader: (0)	Is this the same as replacing the little PCV diaphragm thing? (When the rubber diaphragm gets a tear) Or does the valve cover have other components of the PCV system that can fail?
	Appreciate 0 Quote