a top end overhaul

[JACEK1]

Hello again!

Does "the engine needs to undergo a top end overhaul" mean "the engine needs to undergo a very extensive/expensive overhaul"?

Thank you.

 

[probus]

No.

A top end overhaul is much less than a full overhaul. It does not involve pistons, cylinders or crankshaft. You will be overhauling everything above the top of the cylinders: valves and their seats, valve lifters, gasket etc. I am 100% sure about this, having paid for the overhaul of hundreds of diesel engines.