I’m looking for technical help or recommendations on: Part ID please.
Can anyone ID this part please. Connected to the cam cover. Breather hose nice and snug, however the valve attached to the cover has worked loose. Slightly. Used to be snug. Is this item supposed to be airtight for the vacuum or is wiggle room OK. Not the best description but nevertheless, best I can do. If it needs replacing, part number and how to please. Many thanks. Phil
They do wiggle a bit, most PCV pipes nowadays are clip in so not super tight. In any case I’d suspect if it actually was bad enough to leak you’d see some oil around it or the car being a maf car wouldn’t be running as well as it should.
Cheers Dean. Yup, no leaks and idles, runs fine etc. As a belt and braces, avoiding an expensive new cover, I’ve 3M foam thin striped it, creating a thin gasket around the base and 2 thin cable ties acting as tidy wrap around washers. You’d never notice unless looking hard or specifically at. Nice and snug now. Will run her later to see if there is any improvements or differences. Thanks for the time taken to suggest and info…
While it is true PCV valves tend to have hardened seals after a while, this is not a PCV valve. PCV valves vent gases into the intake manifold, not into the air intake.
The NC PCV valve is white and is on the other side of the engine
Now I need an engineer to explain why there is a PCV valve on the cam cover AND a ventilation tube. I think I understand, but not sure.
My understanding is the vent tube provides a vacuum when the engine is running. At idle, its a low vacuum. At WOT, high vacuum, and on cruise, medium vacuum.
The PCV valve is a spring actuated one way valve that the vacuum can overcome. Its supposed to vent crankcase oily gases straight into the intake manifold.
So, it seems to me, those who fit a small filter to the camcover are actually disabling the PCV valve, because there is no vacuum to the cam cover, and little wonder they end up with a oil soaked filter, or crankcase gases finding another exit, and causing camcover gasket failure. With the engine running, if I remove the oil cap, it not pulling a vacuum.
If there is a leak at the breather, then there is less vacuum under WOT (high throttle) and the valve isn’t operating as normal.
Conventional wisdom states “If neglected, a faulty PCV system will cause condensation inthe oil that leads to blocked passages and damaged bearings, excessive oil consumption, pressure buildup that leads to seal blowouts and oil leaks, and carbon buildup in the intake - any of which could destroy an engine.”
Is this a reason for MZR failures; a leak on a plastic cam cover that people ignore because there is no oil mist?
On UK cars the PCV valve is on the side of the engine block under the intake manifold, not visible to the naked eye and a PITA to change.
The pipe from the side of the cam cover to the intake pipe downstream of the MAF is only a pipe and the part that it attaches to on the cam cover is only a means of connecting it, it’s not a valve although it may contain a restriction. The pipe is referred to as a “ventilation hose”. I am of the understanding (although I can only find this written for ND and not NC) that the ventilation hose is used to transfer blow-by gas upstream of the throttle body during high engine load when there is no intake manifold vacuum to draw the blow-by gasses out of the crankcase.
The pipe ensures that the PCV system is closed to prevent the escape of blow-by gas to the atmosphere.
