Recently my mechanic suggested i change my radiator to double cell for better cooling. I told him that the only time my car over heated was when the water pump went bad water finished in the radiator so the engine over heated. Otherwise, i've not had problem of over heating so why changing to the so called double cell radiator.

My questions are:
1. What then is double and single cell radiators?
2. What advantage/disadvantage does one have over the other?
3. When is it advisable to use one rather than the other?

The mechanic said than once a car engine over heats as in my case, (in my case the temperature meter got to the highest value), the engine may never be same and sooner than later will have to be changed. How true is this? I have asked this because my engine recently started emitting sky blue smoke and "shorting oil" so my mechanic said i have to change the engine. We were trying to trace what could have caused the sudden change in the engine performance. That was when he told me that the over heating could cause the problem.

Could somebody help clarify some of these issues. i cannot trust some of these mechanics anymore.

When a car overheats there's a chance that the head gasket would fail and also that the cylinder head may be warped. Remember a chance and not a for sure thing and depends on the severity and length of the incident.

Radiators could be single core, dual core or triple core like I have in my Mini Coopers. Without getting into confusing debacle lets just say that the more core could mean more effectiveness but also depends on the water pump power.