I'm a little paranoid about the PCV system now (see https://landroverforums.com/forum/lr...morning-79655/) and I noticed on the new engine, there's a pronounced hiss or suction noise that comes from the PCV valve on top of the engine at idle. It is especially noticeable when I remove the dipstick while the engine is running.

Is this normal?

 

The crank gases recirculate back behind the TB and I hear similar when under my hood. As long as the fuel trims look good I wouldn't worry about it.

In my experience the software on these bad boys is pretty sensitive in terms of what it sees as out of limit resulting in a check engine light.

 

I have the exact same thing. However driveability is same. I tried replacing PCV with no luck, so I have two good PCV's, and I have the hard pipe that goes from the PCV back to the engine, will see if that changes anything. I think the hiss comes from one of the fittings on the PCV or the pipe fitting.

I still drive it with the hiss...

 

It is normal.

 

I don't think you're alone in this, as far as I know it's common on these engines. My LPG engineer commented on it, stating "they all do it" when he heard mine. If your car runs ok I'd not worry about it.