The only way to install the original style of plug is to pull the head.

However, you can find an expanding rubber plug at an auto parts store or hardware store.

Get the type that has a hex nut and not a wing nut so you can use a wrench to expand the plug.

The freeze plug is 45mm which is a little larger than 1 3/4".

I have several customers running around with this fix and they aren't leaking.

Don't feel too bad as the original style of core/freeze plugs are not easy to install correctly.

And I have repeatedly commented, I have NEVER seen any installation procedure for this style of core/freeze plug in any Volvo repair manual.

The tools I have for installing the 3 common sizes, 35mm, 42mm and 45mm(there are 40mm, 46mm and 52mm on later Volvo engines), I cobbled together from various pieces laying around my shop. The tools I made mostly keep the sockets I use for dimpling the center in place so I can keep the sockets moving around thus making a nicer looking dimple as opposed to trying to hold the socket in my hand while hitting it with a hammer.

But my tools don't keep me from over or under dimpling so I have whack the socket a couple of times and look to see if I think it is done.

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