Cleaning out a cast iron block

FIRE UP wrote:
TurboJimmy,
Long, long ago in a far away place, (Star Wars stuff, remember?) I used to rebuild engines for side job. When I pulled them and put them on stand to perform surgery on them, I'd take them all the way down to a gain as much access to any portion of the block I could get my little hands on.

Every single time, I'd pull every freeze plug and drain plug. You'd be surprised on how much SAND I'd find in there, big chunks of black carbon, solid chunks of pure rust etc. I'd have to pry much of it out and or, use a chisel and break much of it up to be able to remove it through the freeze plug holes. Once all the debris, sand and other big stuff was removed, then I'd hit with special, long nosed nozzle that I had for my garden hose. You'd still be surprised at what came out as a result of using that nozzle.

That was then, (from about '65 to, oh around '90 is when I quit that non-sense) and this is now. Unless it's an old hot rod, i.e. '60s Chevy etc., I won't even think about pulling an engine in a motor home. But, back to your issue. Yep, pulling the freeze plugs is the least you can do to get the closest inspection at the cheapest cost. Freeze plugs are cheap.

If you have one or, have access to one, you can use an "Inspection camera" to get into many tight places, inside the water jackets of that block. You know, the kind that Home Depot, Lowes, and other tool places sell. I got mine from Costco quite a while back and, it's not the best but, it sure works for getting into very tight places and seeing what's in there. Good luck.
Scott

Thanks! I'll start with the drain plugs, assuming I can free them up. If it looks bad, I'll start pulling freeze plugs. I'm hoping that the problem was the clogged radiator and not clogged coolant passages - maybe the gunk made its way through the block and accumulated at the radiator inlet. The rad shop told me that the stock high efficiency radiator is made of many smaller tubes rather than some smaller amount of larger tubes. Smaller tubes clog easier. Dunno.

Yanking the engine out isn't really that bad. On the '84 there's not a lot to unhook. The 454 comes out the door easily without the exhaust manifolds on it. Everything is easy to get at. Not that I want to do it again, but far better than replacing the TCC solenoid on a FWD Northstar Cadillac, for example (top of the list of things I will never do again).