Who can diagnose this?
#11
Heres the one i got. I like it.
#13
Bore scope came today. Checked my cylinders. The mirror that it came with I couldn't see anything to see any scarring on the walls but looking straight down in I can see the top of my cylinder 4 with oil on it and running down the side of the walls.
#14
Check your valve clearance, if they're tight your seals will be the first thing to go. I would have gotten OEM seals, the intake ones are a different size than the exhaust. It's best to leave the guessing to Honda. They're also pretty cheap from Honda.
#15
Right. Oil pooling on top of piston indicates valve seals. The concern is if valve guides are bad or not.
#16
Since it is primarily only affecting one cylinder and compression is good across all cylinders maybe just take a guess that the guides in #4 are ok, replace the seals, and watch it? Is that the thing to do? Is there a way to assess the guides without pulling the head? Maybe just have an experienced hand give the valve stems a little wiggle from the top with the springs off and rule out any dramatic guide wear?
Last edited by rpg51; 03-13-2017 at 05:04 AM.
#17
I want to tackle this job myself, but I called Honda and a local performance shop anyway to get a price quote. Honda quoted me $920 for labor. I'm still waiting on the local shop to call back when they aren't busy. I ordered OEM seals from Honda. Apparently they only come in packs of 10, so for 10 of each seal came out to $40. I'm going to just hope the guides are good and just press on with what seals. Hopefully I am able to get to it this weekend.
#18
The supertech ones are also different sized between exhaust and intake?
#19
You can check if the guides are bad once you pull the valve spring. With the valve dropped about 1/2" into the cylinder wiggle it, there shouldn't be any more than a tiny imperceptible amount of play. If you can hear the valve make noise when you wiggle it(from slapping the guide walls), you have worn guides, and it's only a matter of time before the guides mess up the valve seat.
The service limit for valve guide play is .009" on the exhaust .006" on the intake, measured with a dial indicator with the valve 10mm, or a little less than a half inch off it's seat, any more than that and you'll eventually have ovalized valve seats. If you did the valve adjustment to specs, you know what .009" of play feels like, and it's not a lot.
Like previous posters mentioned, if the compression and leakdown are good chances are the valve seats are fine, and the guides are within specs.
The service limit for valve guide play is .009" on the exhaust .006" on the intake, measured with a dial indicator with the valve 10mm, or a little less than a half inch off it's seat, any more than that and you'll eventually have ovalized valve seats. If you did the valve adjustment to specs, you know what .009" of play feels like, and it's not a lot.
Like previous posters mentioned, if the compression and leakdown are good chances are the valve seats are fine, and the guides are within specs.
#20
Registered User
you could inspect for oil buildup on the valves by peering through the exhaust/intake ports.
why is there no carbon buildup on your pistons after 170,000 miles?
why is there no carbon buildup on your pistons after 170,000 miles?