After process of elimination to find the cause of my overheating engine, Westerbeke 13, (210 - 225 degrees), my heat exchanger has an internal leak! I brought it home to rinse out with vinegar and confirmed (with food coloring) that the raw water side is leaking from the "thin tubes" with the anti-freeze side. Can this explain the overheating? Interestingly, my antifreeze levels were never low. I assume the antifreeze side has higher pressures than the raw water side but levels didn't drop. Can this be repaired or is it time for a new heat exchanger? Should I look for another cause for the overheating? Thanks!