[JLL]

Could anyone @XtremeRevolution explain exactly how the PCV diaphragm regulates the pressure inside of the crankcase? I'm trying to figure out if it would be possible to leak intake vacuum INTO the crankcase WITHOUT the diaphragm leaking externally. If that makes sense.... Thanks!

 

[JLL]

The PCV valve in the intake does not leak externally, it fails and allows the vacuum/boost become unregulated in the engine. Instead of a valve, it basically becomes a hole. An external leak may be eventually caused by this valve failing as it allows the block to become over pressurized and possibly blowing out the valve cover gasket, causing the oil cap to open, the front crank seal fail, the oil pan gasket to fail etc.

I'm not asking about the check valve in the intake manifold. I'm asking about the PCV diaphragm in the valve cover.

 

[JLL]

Yes, it is possible to fail in such a way that excess vacuum is applied to the crankcase. I see it quite often. No leak at the vent but the dipstick is so stuck in there that it's like trying to pop a Cork out of a bottle.

Sent from my BlackBerry Key2 using Tapatalk

Thanks for the reply.

 

[JLL]

Sorry, I did not see that you were asking about the regulator.

No apology needed

 

[JLL]

I have a 2015 Cruze factory intake with a bad PCV check valve if anyone needs a factory core to perform the external PCV fix upon. I will ship to you for roughly the cost of shipping only. Email at [email protected] or text 704.9O5.423O.
I will package and check with USPS for exact cost for a committed buyer.

You would probably be better off creating a For Sale thread here:

Cruze Parts

FS, FT, WTB: Chevrolet Cruze parts ONLY - This upper node is for parts that work for both generations.

www.cruzetalk.com

 

[JLL]

Okay so I'm wondering if these external kits are available, I'm pretty sure my intake will need it... I looked in there the other day and didn't see the little red thingy... also curious about the hissing noise, where does the hissing noise come from? Mine sounds like it's around the intake and only does it under boost pressure... turbo was replaced a few weeks ago and developed a boost leak and throws a p2261 code.

They sure are.

www.cruzekits.com

 

[JLL]

So I've been working on my sister's 2012 Cruze doing some long overdue maintenance. Struts, shocks, fluids, plugs and everything in between. Oil consumption, leaks and poor fuel economy (10 mpg) is what I'm seeing.
I stumbled upon this thread last week while researching some things for her car.
Tonight I ordered a 3.4 kit, thanks XtremeRevolution!
I did the three checks, valve cover diaphragm checked okay, intake check valve missing and pcv pipe to turbo check valve good. My concern is the valve cover. The idle didn't change when I covered the hole. The cap to the diaphragm is concaved inward, this normal?
My concern is, since this car appears to have had less than stellar maintenance and no history, should I go ahead and replace the valve cover or is the test I did good enough to verify all is well with the cover?

There's no reason to replace a good valve cover. If it doesn't leak and the crankcase holds the correct amount of vacuum, it's a good valve cover.