testing PCV

azureblue · Post by **azureblue** » 30 Oct 2023, 18:23

I read that a clogged PCV system will create a vacuum at the oil dipstick tube. Under idle at maybe 1K, I get a mild vacuum. At about 97K miles, does this mean I need to replace the PCV valve? Or is a mild vac Ok?

Thanks

Post by **Krons** » 31 Oct 2023, 05:39

A rubber glove over the oil fill after removing the cap should suck in toward the engine. Definitely should not inflate, or the pressurized engine will start pushing out seals.

If it fails this test you should change the PCV parts. What engine you have?

azureblue · Post by **azureblue** » 31 Oct 2023, 07:04

it's a 2014 S60 t5, 5 cyl., , and this engine does not have a lip to attach a rubber glove to.

Post by **volvolugnut** » 31 Oct 2023, 07:45

Can you use a plastic zip tie to attach a glove to the oil fill opening? Or get a used cap and add a small pipe nipple to the cap?
volvolugnut

azureblue · Post by **azureblue** » 31 Oct 2023, 16:32

There is no lip to attach anything to - the cap is flush. The dipstick shows a mild vacuum

Post by **Krons** » 31 Oct 2023, 18:28

Don’t overthink the glove test, I’ve even laid a plastic shopping bag over the oil fill. If it sucks toward the engine you are good. Just don’t let it suck it into the engine!

You just want to verify it has vacuum and the engine crankcase isn’t pressurized.

azureblue · Post by **azureblue** » 01 Nov 2023, 07:29

Thanks - So if there is a mild vacuum at the dipstick, that is the same a vacuum at the oil filler cap?

Post by **Krons** » 01 Nov 2023, 18:33

azureblue wrote: ↑01 Nov 2023, 07:29 Thanks - So if there is a mild vacuum at the dipstick, that is the same a vacuum at the oil filler cap?

Never heard of folks using the dipstick verify the PCV is functioning. I’d pull off the oil filler cap and double check .