HELP!!! We have a Discovery Series II V8 that had water in the oil and was overheating we pulled the heads and had them pressure tested and surfaced (both were warped) reassembled and test drove about 15 miles with no problems. returned to shop and parked and let idle for 1 hour then it began to overheat and has water in the oil again. WE NEED HELP PLEASE!!!

 

You more than likely have a dropped cylinder liner. There are steel liners in the cylinder bore that can drop after the block overheats causing the gaskets to not seal properly. You need a new engine block. roverlandparts.com sells used complete engines, I can't find a site that sells just engine blocks right now.

 

Atlanticbritish.com sells short blocks, which is the engine without the heads.

 

Craneman, just went through this SAME exact thing, found a used motor for $500 and am currently installing it

good luck !