94eg!

iTrader: (2)

Old thread I found, but I'm now in the same boat. I ran the test on my J35 V6 (from an 04 Pilot) and double checked everything. Still got the same results.

Compression Test:
- Engine fully warmed
- Brand New OTC Compression Tester
- Long Reach test adapter (matches plug length)
- All plugs removed
- WOT
- 10 compression cranks

1 - 235psi
2 - 230psi
3 - 232psi
4 - 231psi
5 - 227psi
6 - 235psi

Leak-down Test:
- Performed imediately after compression test
- Brand New OTC Leak-down Tester
- Each cylinder set to TDC
- 75psi Test pressure

1 - 1% (74psi) - into crankcase
2 - 5% (71psi) - into crankcase
3 - 4% (72psi) - into crankcase
4 - 7% (70psi) - into crankcase
5 - 44% (42psi) - into exhaust
6 - 4% (72psi) - into crankcase

I would think a stuck, burnt or miss-adjusted exhaust valve would also cause low-compression readings

DumpdEJ6

This may be completely off-base, but my Subaru Forester also had this issue, even in neutral it wouldn't rev out past 3k rpm. Turns out the catalytic convertor had melted and was literally choking the engine past 3k. If no air can get out, no air can get in.

I know it doesn't take into account the bad leakdown results, but just throwing ideas out there since your mechanical timing seems like it's good to me.

EDIT: didn't see it was an old thread, not sure if this pertains to your issue, 94eg!.

94eg!

iTrader: (2)

According to Honda's flowchart, it could be overly tight valve lash on the exhaust for that cylinder. I waited till the next morning and popped the valve cover off. One of the two valves seemed tighter than normal. Directly after adjusting it, that cylinder managed only 8% leak (69psi). This was with the engine stone cold after sitting overnight.

Engine still runs funny though. Booooo. But at least I know the bottom and top ends are both sealing.