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Cute little trick to diagnose blocked CCV system...

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I just came across this interesting little trick for diagnosing blocked CCV in the Volvo forum:

With the oil cap sealed, engine on, stick a balloon over the dipstick tube and see if it inflates. If it inflates you need to service the PCV system.


I think he meant with the dipstick removed, so the balloon goes over the dipstick housing.

No balloon, no problem, get an old dish washing glove, cut a "finger" off and tie it with rubber band.
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This was from my 2001 530i, it had a failed CCV and the dipstick tube (original non-updated version) was clogged

When a PCV system fails, usually it is from a clog ---> increased crankcase pressure ---> oil leak past the seal etc.

The video you posted above is from a different mode of failure: too much suction. Funny enough, this is exactly what you want in an M54 engine to reduce oil consumption.
The "BavarianE39 mod" is exactly that: creating a lot of suction to reduce oil loss from leaky piston rings.
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