I honestly don't know, but I do know I even used to hear the same thing on CarTalk (man I miss those guys!). I just don't want him to make a decision without hearing both sides, and I don't claim to have any experience myself. I just know that if it were my engine, it wouldn't be worth the risk to me. Any risk of the cooling ports in the block itself getting plugged is too much risk IMO, but if someone else decides it's worth the risk to them then more power to them.

 

Fair enough. It's certainly good for the OP to know there are risks associated with the product. I personally have never seen an engine block with water passages small enough that they can be easily blocked. Typically, water passages are as open as they can be so coolant can flow easily. Radiators are where the coolant passages are small so the coolant will cool quickly as it passes thru, and correspondingly radiators are what I have heard about getting stopped up using a liquid glass leak sealant.


That said, I certainly haven't examined tons of engine blocks, so I could be wrong.

 

The problem with using chemical sealers is not the block never is it all the problems they cause with the rest of the system like blocking heater cores, radiators and thermostat.
If it a last ditch effort go for it.
You can bypass the heater core but hard to by pass the radiator.

 

Use the Force Luke.

Dooooo the head gasket

https://www.flickr.com/photos/76579732@N07/

http://jeffreyfall.com/jeffreyfall/landrover

 

Of course, you can't go wrong doing the head gasket, BUT:
In my personal experience, (yours may vary) the coolant leak at the right rear side of the engine was definitely absolutely the intake manifold gasket. A previous owner had the head gaskets done, and the IM job was simply botched. A compression test will tell you if you need head gaskets or simply intake manifold gaskets.

When I replaced my water pump, I discovered, upon removal of the old one, that there were several bolts that were less than finger tight. In other words, loose. See comments above about botched job. I figured tightening the bolts would likely cure my water pump woes, but I changed it anyway: I had gone this far, and I had a new water pump on hand.

 

I think the compression test is the only test I haven't done, but I don't believe I have the equipment for.

 

A compression test wont always tell you whether or not its HG on a D2 because often (like mine) the head gasket goes out between the water passage and the outside world instead of between the water passage and the cylinder.


Valley Pan gasket I a good guess, but honestly if I had it down that far and my head gaskets had a chance of being bad I'd just replace them. At that point you only lack the exhaust manifolds and the heads themselves.

 

True that; I had forgotten. In my case, very careful inspection revealed cause of leak.

 

Do the head gasket job. Why stress yourself wondering if or when it will fail and leave you stranded. Just do it already. You know it is leaking so start buying parts. Once you have all the parts and tools you need knock it out.

 

^what he said!