J35 from a 2010.
boatload of issues leading back to bank 2 misfires. (4,5,6 front of car - cyl 4 has VCM as well as 1,2,3)

re-ringed 4,5,6 and quick 3-stone to deglaze the walls.

remanufactured cylinder head from Jegs - old one had leaking valves.

car ran great for 100 miles and then lost power and refused to start.
towed it and messed around with fuel parts.
it started, but literally on 3 cylinders. Plugs out on 4,5,6 to see if fuel would spray out and it started.
put plugs and coils back in and starts.
really bad idle for about 30 sec and then jumps to 3k RPM and blinking cell. Codes for misfires on 4,5,6 and random misfires bank 2.
checked live data - misfires start immediately on all 3 cylinder until a count of 250 before it goes to the 3k RPM.

checked for spark on 4,5,6 and it seems good.
test be removing pugs and coils and attaching them outside and resting on the install cover while cranking.

checked compression. 120s on 1,2,3. Mid 60s on 4,5,6. Weird.

checked belt timing. Dead on correct.
checked by removing accessory belt, crank pulley, and cover for bank2. Wanted to make sure everything is spinning.

while turning the engine by hand, there are definite tight spots. Does not feel smooth at all.
Dropped oil pan and removed pressure plate/torque converter screws to rule out the trans.

loosened connecting rod bearings and checked bearings to see if I messed anything up when I reassembled from re-ringing 4,5,6. All good.
left them loose and turned engine. Still tight spots.

Seems to be 2 tight spots about 30 degrees apart.

thoughts???
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Hey there,

By just reading what you have posted, I would remove and check piston/rings of cylinders 4,5,and 6. As you have stated that those cylinders have low compression and those are the cylinders that you have re-ringed. You could have mistakenly swapped or flipped rings. Aside from the rings, check if the valves for that bank are sealing correctly.

I'd say your next step is to perform a leak down test. This will be able to tell you if the cylinder is holding pressure. If its leaking, it can either point towards the valves not seating or its going pass the rings, into the crankcase (take off the oil cap and listen).

 

Valves adjusted? Do you have access to a borescope?

 

Any updates on this low comp bank #2?

Have you verfied that bank #2 valvetrain? Cams have been known to wear and delaminate and the oil passages in the rockers and shaft could have gunk in it causing oil pressure starvation to the valvetrain.

Im currently in the same boat as you on my 2009 Odyssey (j35a7 with VCM-2). Has random misfire and the front bank is always misfiring...and smokes badly when running on 6 cylinders... But no smoke when in VCM mode. Changed coil packs, plugs, and sent the injectors out to be cleaned. Timing is spot-on I just ordered all new OEM pistons and rings and will be swapping all 6 pistons out (like the Honda TSB specifies) Wasn't sure if I should deglaze or ball hone the cylinders at all. Looking at the all the Youtube videos of Honda dealerships and I talked with a couple technicians, they dont deglaze or hone. They just drop in new rings and pistons and call it good.... This goes against whatever I thought I knew about .. But if they don't get any "customer complaints" after the fix... it must be working, right?