What should compression be in a 88 5.0?
 

I am looking at an 88 5.0 and I want to do a compression test on it before I buy. What should the numbers be for a motor in good shape?

Thank you.

Marc

So?

Depending on how you do it, maybe between 150psi and 180psi (that's a ballpark estimate) they should all be within 75% of each other according to Ford (any more differance indicates a large problem). Make sure to do the test with the engine warm, all plugs out, and with wide open throttle. Hope this helps.

I'd say shoot for 150psi, but as previously stated, it really does depend on several things. Most important is that the results are uniform. The highest reading shouldn't be more than 20% higher than the lowest reading. Also as mentioned, make sure the engine is warm, all plugs are removed for the entire test, the throttle is blocked at WOT, and the coil is disabled.

Take care,
-Chris