I am repairing a 1990 245 with what I hope was only a blown head gasket.
While putting it back together I noticed one of the driver side freeze plugs is installed backwards. I said " What a fool!" After removing it and attempting to re install a new one I noticed the block has a lip that prevents installation in the normal manner, like the other freeze plugs. My 1992 is not like this, all plugs have the oval facing in. I said "What a fool!", and put the new one in just like the old one I removed . Anyone know why this is? There is not nearly the gripping surface on this plug vs the others.

Volvo made a running change to the soft plugs in the 1990 model year. The earlier style is installed with the slight dome out, and struck firmly in the center to expand it into the hole in the casting. Yes, there is a ridge in the block to keep the soft plug from going into the coolant passages when you set it in place. The soft plugs have some kind of sealant put on the edeges before they are set in place. There are many opinions on what sealant is best, but they aren't supposed to be installed dry.

If you have doubts about how will the soft plug will seal, mix up some JB Weld and put it around the edges.

I prefer the late style soft plug like your 1992 car uses, but there must be hundreds of thousands of the early style sealing fine for many, many years.

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john

Thank you for the info. Wish I had not re installed the exh. manifold!
I will JB weld the plug I put in and leave the others alone.

^

It sounds like someone installed the later 40mm cup style plug in place of the 40mm disc type plug. To do so, the plug has to be installed backwards.

1 of my suppliers insists this is okay, but we don't agree.

I try to keep in stock ALL of the OHC freeze/core plugs, both early and late styles and I now stock the cylinder head locating dowels too.

Most of the plugs are Volvo OE, but I do have some aftermarket plugs, specifically the early 40mm disc style and the cam plug for the back of the block.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Hi,

That's good to know, Eric. My first and only experience with the disc type was a few years ago when I was putting a block heater on my daughter's 89 240. I wanted to have a spare on hand in case things went wrong and I had a heck of a time finding one.

The disc is a lot thicker than the cups I've remover before and I couldn't penetrate it with a screwdriver. I drilled a 3/16 hole in it and screwed in a 1/4 lag that I hooked to a slide hammer. I hit it repeatedly and hard enough that I thought I might break the block, but it wouldn't budge.

I though I'd put some heat on it, let it cool and try again. After making a cherry red spot the size if a penny, I heard a plink while I was hanging up the torch. Then I went and picked the disc up off the garage floor, a nice surprize.

I'm guessing they can be removed by driving the center inward with a blunt tool. I might have tried that at the time but I wasn't aware that the block was backing it up and thought it might have ended up inside. How do you remove them?

As an added note for reference, I put the heater into the second hole on the driver side. After removing the IAC valve and a few hoses, there's a clear place to work, and much easier than the recommended rear hole on the passenger side, which is painful. It's been working perfectly well.

Peter

Hello Peter,

To begin, the idea of putting the block heater on the drivers side away from the exhaust is brilliant.

I have installed a few of that style of block heater including on my own car for a month long vacation in Jackson Hole, WY.

But all of them were installed on B18 or B20 pushrod engines and although they do have core plugs on the drivers side, they aren't for coolant, so the block heater has to be installed near the exhaust on the passenger side of the block.

With the engine removed, I use a fairly large rolling head bar (see picture below) and a hammer and if the engine is in a car, I use an air hammer with pointed tip.

When removing, I aim off to 1 side about 1/2 way between the center and the edge and at an angle to avoid hitting a cylinder wall that might be behind.

The diameter of both the tools is such that without much penetration, the disc will deform enough to be popped out by prying with rolling head bar or the air hammer bit.

FYI, proper installation of the disc type plugs is nowhere as easy as the later style of plug.


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

I remember seeing a comression type plug for the B18 engine made of rubber with a plate on each side . It was tightened down compressing/expanding the rubber. Easy install no matter which feeze out plug needed replacement

I can tell you that that expandable freeze plugs are an effective temporary repair. The nut must be re-tightened after a few days of running and after some time installed the rubber will harden and not seal anymore. I used them on a customer's '75 245 w/B20F until the car could be left for proper repair. Fit them ALL the way in. -- Dave