How can you tell if the top end is bad?

Question

How can you tell if the top end is bad?

Answer 1

The combination of a compression test and leak down test should tell you everything you need to know.

Answer 2

You need a compression tester. Take out a sparkplug then s***w in compression tester turn the engine over and record the compression results. Remove compression tester squirt some engine oil directly into the cylinder then put the compression tester back on and crank the engine, record and compare the results. If your compression goes up your piston rings are had (bottom end). If it does'nt go up and compression is low your valves are had (top end). Repeat for all cylinders and for the test don't let the engine start disconect all sparkplug leads or coil wire which ever is easier. Only remove 1 sparkplug at a time. Good luck.