The VTTO valve cover breather to solve PCV Squeal

[guslealisla]

I am writing this to see if anyone has made this attempt and if it worked.

I currently have the squealing that is a result of overpressure from either the pcv valve, the valve cover, or the front or rear main seal. I purchased the PCV valve and I plan to hack it to replace it. However, I have found that for most the issue arises again. This seems likely due to tuned higher power configurations.

I see that the VTTO crankcase breather is popular on the n54 and does fit the n55 although maybe not DOT compliant...

Has anyone tried this as a solution?

https://vargasturbo.com/product/vtt-...case-breather/

[ferocity02]

You don't want to run an open breather. There are multiple good reasons for the crankcase to be under vacuum during normal operation.

I suspect you can easily "externalize" the vacuum side of the PCV system. Run an external PCV valve and route it back into the intake manifold. This is a common mod on N54's and I did it myself.

[iminhell1]

Originally Posted by ferocity02

You don't want to run an open breather. There are multiple good reasons for the crankcase to be under vacuum during normal operation.

I suspect you can easily "externalize" the vacuum side of the PCV system. Run an external PCV valve and route it back into the intake manifold. This is a common mod on N54's and I did it myself.

It's not an open breather.

Originally Posted by guslealisla

I am writing this to see if anyone has made this attempt and if it worked.

I currently have the squealing that is a result of overpressure from either the pcv valve, the valve cover, or the front or rear main seal. I purchased the PCV valve and I plan to hack it to replace it. However, I have found that for most the issue arises again. This seems likely due to tuned higher power configurations.

I see that the VTTO crankcase breather is popular on the n54 and does fit the n55 although maybe not DOT compliant...

Has anyone tried this as a solution?

https://vargasturbo.com/product/vtt-...case-breather/

The squeal is a result of under pressure, or too much vacuum in the crank case.
Over time the lip on the front/rear seal gets brittle. This does not allow it to hold back as much pressure as it did new. The only fix here is replace seal/s.

The more common problem is a crack in the valvecover.

Also, page 12:
https://www.1addicts.com/goodiesforyou/n54-3.pdf




In the pic, Red is active under pressure, sucking air in.
Yellow is active under vacuum, sucking air in.



On modified cars, lets say pushing two times the factory boost and above, and/or those with high miles and loooose rings, The problem becomes a flow issue. The clogged ports and the small PCV valve just creates too much restriction and air can't pass fast enough, building pressure.
The yellow side is very flow limited for high boost cars and is in part why many (everyone should) the 'head ports' are blocked and the pressure side of the PCV is eliminated ... this is where to 'PCV delete' cap comes into play.

[guslealisla]

Originally Posted by iminhell1

It's not an open breather.


The squeal is a result of under pressure, or too much vacuum in the crank case.
Over time the lip on the front/rear seal gets brittle. This does not allow it to hold back as much pressure as it did new. The only fix here is replace seal/s.

The more common problem is a crack in the valvecover.

Thank you for the information. I have a 2011 with an N55. The engine was rebuilt and it has new seals but the stock valve cover. It appears that the PCV system is different in the N55.

Yesterday I changed the car to map 0 and the squeal is gone however it does still seem to have an odd pressure or vacuum sound that is much less audible.

I would imagine the issue is my valve cover, I am going to attempt the PCV valve replacement but I don't have much hope for it working. If it doesn't then I will need to replace the valve cover when I get an exta $1,000 ( I would have the shop do it)

Thanks again

[iminhell1]

PCV is not serviceable on the N55.

Sounds more like you have a vacuum leak. Check the lines to the turbo.