I have a 1983 RX-7 with the 12A engine. The engine was rebuilt by someone who supposedly knew what they were doing, except when I stuck a hose in the radiator to fill the cooling system it started to float the engine oil out of the crankcase. This is not a weepy little leak between the two - we are looking at a BIG connection here.

Any suggestions on where to look? Before I initiate a teardown I wanted to look for the simple(?) stuff - oil cooler? (this car has the engine-mounted cooler, not the front-mounted air-to-oil cooler). Anything else? I figure a water jacket seal would not allow the coolant to flow into the crankcase that that rate, but I don't know a heckuva lot about these engines.

Thanks

 

Only thing I can think of is that one of the crankcase vent hoses is hooked up to the coolant system by mistake.
You will have to take a good look and distinguish the Coolant system from the oil system and vacuum system.

 

Thanks. I am hopeful it is something simple like that - however I don't necessarily see crankcase "vents" as such.

The plumbing around the oil cooler seems pretty simple - the one oil connection is internal and the other is via the banjo fitting near the firewall, through a bit of hard tube to a boss on the front of the block. One coolant hose/tube comes from a tee on the lower radiator hose nipple and another short one connects to the block just below the oil cooler. Both of these have tees that go through the firewall to the heater core, so I know they are coolant lines.

I'll keep digging.

 

I think he's talking about the line on the oil fill tube.