I had to replace my water pump and found a non used section of the water pump corroded. when I cleaned it out there was a pin hole in the timing cover. it looks like the hole is from corrosion on the water pump side, not from something rubbing on the inside. any thoughts on this? leave it, replace or some jb weld? I should state that I really do not want to replace unless it is a must. pump was working fine, the small water tube for the heater corroded is the reason for replacement.