1970FuryConv
Old Man with a Hat
I have a 1970 318 original engine in a Fury. The engine is leaking coolant on both sides of the block. I thought that the problem could be fixed by removing the old rusty freeze plugs and replacing them with 4 rubber expansion plugs from Advance. Did the job, I pressure tested the cooling system, and the test was perfect at 16 psi. Drove the car. No leaks. Came back a few days later, coolant on the garage floor under the engine. A few months passed, always the same thing, drive the car, no leaks when I parked it, puddle a few days later. I drained the cooling system again, including removing both block drain plugs. I then removed the rubber expansion plugs, so the block was completely drained. I hammered in new brass freeze plugs and DID NOT add antifreeze. A day later, I have the leak at the center of each side of the block, even though the block is drained. There are droplets on each side of the block at the oil pan rails, oil pan, auto trans cooling lines, and right side exhaust pipe, plus small puddles on the floor below side of block. I'm wondering if the heads could have warped upward in the center just enough that coolant pooled somewhere in the heads is draining out the between the bottom of the head and the top of the block and then down the side of the block - masquerading as a freeze plugs leak, but actually a much larger problem. Could coolant have pooled somewhere in the heads and be draining out as I described? Could a block with this slow leak pass a pressure test? The block was completely drained when I installed the freeze plugs. It's hard to believe that the coolant is coming from the block. Left side of block below, but leaking both sides.