hand banana

@Billman250

rpmgem

PM’d Billman for a rebuild list

Billman250

Did you completely rule out the intake and exhaust valves as source of the compression loss?

rpmgem

Are there for for sure signs that tell it’s the intake/exhaust valves? My mechanic basically just assumed it’s the rings. I could hear the air escaping during the leakdown but was hard to tell exactly where it was leaking from

Slowcrash_101

You can tell if it's the rings by putting a small amount of oil in the cylinder and doing a compression test. If rings are bad, if you put a bit of oil(like a tsp) in the cylinder it will bump compression. No change then it's either valves or head gasket.

Honestly though I doubt it's rings, since it's only one cylinder, the chances of bent or burnt valves is high.

rpmgem

Appreciate the compression tip I’ll redo the compression test adding a bit of oil to cylinder 2 and see if anything changes. What gets me thinking is the head has around 30k on the rebuild and no mis-shifts that would cause a bent valve. Will report back with the updated compression results, thank you to everyone chiming in

Billman250

Compressing test is useless, only a leakdown test, following the audio signal of the leak, will determine valve condition.

rpg51

I have little doubt that the first thing he will say is that you don't decide the treatment until you have the diagnosis. Also, if ends up being a bottom end problem, think long and hard about embarking on a rebuild project with this engine. These pages are filled with failed bottom end rebuilds. Its a tough engine to rebuild. Lots of good money thrown after bad. That's my take anyway.

rpmgem

UPDATE**

So I redid Compression today:
cylinder 1-160
cylinder 2-80
cylinder 3-155
cylinder 4- 170

I added a small amount of oil in each cylinder for a wet test and each cylinder bumped up about 10psi. When we did the leakdown, I heard air escaping not sure exactly where. My mechanic was already saying it’s rings but with the wet test what do you guys believe? Bad valves?

rpg51

The diagnostic data you are missing is the location of the air leak during the leak down. I wouldn't make any decisions without that information.