Freeze plug from hell.
 

What a fun night I've had.

On my 87 R10 6.2 Diesel, the left rear freeze plug on the side of the block was weeping. It has been getting worse, to the point that I was losing about 2 cups of coolant at night when the block would cool off.

I decided to change it and found the left exhaust manifold in the way. When I went to remove the manifold, the bolts hit the frame before they are fully removed from the manifold, so basically I get them all loose from the block, lift the manifold and they all fall down into the pan I had catching the antifreeze I drained.

The freeze plug itself was fairly straightforward except I couldn't swing a hammer to drive the old one out or the new one in without hitting the frame, control arm or shock. I finally used a handle off of my pickle fork and my 1 1/16" socket to successfully drive the old plug out and the new one in.

After three hours, I finally got the new plug in and the exhaust reinstalled by teeter tottering the bolts, a manifold gasket and the manifold itself to get the manifold in place. I didn't have the 6 or 8 gallons of antifreeze / water over at my shop so I didn't even drive it home.

I probably should have changed the other five freeze plugs, but two are behind engine mounts, two are behind the starter and one is the block heater. I guess I will do them when they start leaking!

That thing really makes me like working on my small blocks in my other trucks!

Re: Freeze plug from hell.
 

In situations like this I usually stick with the old saying...

If it ain't broke dont fix it.

Sounds like you had enough irratation changing one freeze plug.

Hey Joe, I know this won't help now, but I've got a couple of tips.

The reason the exhaust manifold bolts wouldn't come out is because your motor mounts are wearing out. I was doing some exhaust work one day on my 6.2L, and I had the same problem. I had been able to remove the manifold before with no problem, so I was kind of stumped. After looking at the motor mounts, I discovered that the mount on the side I was working on had come loose, so the engine was sitting lower in the frame rails than it was supposed to. The 6.2L is hard on the motor mounts. Mine don't seem to last longer than 50,000 miles before they start sagging.

If you need to do the work again, either replace the mounts, or just put a jack under the motor and lift it up a bit. It helps a bunch!

Also, you can buy rubber freeze plugs that clamp into place, in cases like yours where you can't drive them in.

Wish I could have helped sooner!!