I buy those core plugs from a speciality wholesaler that still carries some parts for the old Volvos as Volvo no longer sells them.

I was not aware that Dorman has the correct size.

To remove the disc type of core plug, I use a punch with a pointed tip called a rolling headbar and for the front 2 core plugs, I punch a hole in the middle. Once through the plug, I pry sideways back and forth and the plug will come out.

FYI, the core plugs on the same side as the oil filter are removed differently.

I don't punch a hole in the middle as it is possible to hit a cylinder wall with the punch if you aren't careful, so I punch slightly off center and at an angle away from center.

Yes, there is a ring/ridge on the inside of each core plug hole that acts as a stop so the plug doesn't fall in. You need to clean this area scrupulously to ensure a good seal.

Why mess around with the wrong size core plugs? I have plenty of the correct size in stock for $2.04 each plus shipping.

--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502