TroyN

I've searched but some said that some vacuum at the oil filler is ok, some said no. Which is it? I have suction but not the strong, can't-remove-cap type. Thanks!

deliriousga

There should be vacuum at the filler. To see if there's a problem with the separator, pop the engine cover and see if the oil filler tube is collapsing. If so, there's too much vacuum from the broken diaphram in the oil separator.

TroyN

Aha! Thanks for the reply, I'll check that.

Macster

gone out -- though I didn't know at the time it was the AOS (air/oil separator), I found with engine idling while I could unscrew the oil filler cap I couldn't remove it against the vacuum. I never looked at the oil filler tube to see if it had collapsed from the vacuum.

A healthy engine, with a healthy AOS, should not only have a bit of vacuum at the oil filler tube opening (with of course the cap removed!), the engine should be able to react to/compensate for the air leak removing the cap produces.

Sincerely,

Macster.