| Moreso trying to see if I have any other options before pulling the head... again History: I rebuilt the Z engine, had it bored + 0.5mm, heads decked and completely rebuilt/reground. After initial assembly, I was having issues running on 4 cylinders. Narrowed it down to bad valves (Exhaust valves sticking open) see HERE Got it back together 6 months ago, was running OK. Ran an ECU power balance test and... cylinder 6 still not contributing. So I disconnected the injector and drove it into my garage. Been working on other projects for the last 4 months but finally got back around to the Z. After tearing it down again... Leakdown test shows cylinder 6 intake valve is leaking. See below Left valve not closing fully (Picture taken with cam and lifters removed)
 Valves open (Reinstalled cam and lifters)
 I don't see anything obvious on the valve stem that would cause it to hang up, using the bore-scope again the gap seems even all around suggesting the valve isn't bent (Or if it is, very slightly) Anything else I should try before removing the head, and finding a new machine shop to fix the old machine shops (two round of) mistakes?
------------------------------------------------------------------
1992 300ZX NA 5 Sp (Dead)
1990 300ZX NA Auto 2+2 (Dead)
1990 300ZX TT 5 Sp (Est. 400 HP)
1990 300ZX TT 5 Sp (Est. 600 HP)
2004 G35 Sport 6MT (DD) |
Opinions on Valves Sticking - 
