Could consider the mod with a metal external check valve as well.

 

I bought this one, coming from Ukraine and will supposedly arrive tomorrow. It was linked from a youtube video that did a deep dive on the issue . https://www.ebay.com/itm/116338088398

 

Easy job too mate, if when you take the old one out the rubber membrane is gone you’ll know it needed sorting.

 

Remember to fish out the debris in case it clogs the pump.

 

When I took off the hose to check a week ago, there wasn't any oil residue and it was making the correct noise as per the videos I've seen of correctly working check valves, but I figured I should give it a shot for 30 bucks. Car is 12 years old , but only has 65K miles on it. I noticed it was way more sluggish than it should be after getting a Dragy a couple of months ago, so I'm working through trying to diagnose it.