#1 cylinder
92 22RE 120K

Just pulled the plugs and here is a pic of #1 plug. Others look like they've been there too long, but not wet or corrosion build-up like this one. No idea how long these NGK plugs were in there, wires are orig, maybe plugs are too? But the wetness and dark tannish/greenish (dare I say) corrosion concerns me. Truck runs fine and never overheats but I've only had it a short time. Timing guide was broken which I just replaced. Checked the valve lash while cold, and all seemed too small of a gap so I adjusted to .007/.011 cold. Truck did not smoke or anything like that and didn't notice any water in the oil or vise-versa. No smell of unburnt fuel when running and plug does not have a gas smell. Thanks!

 

Looks like cokeing (burnt oil), can see liquid iol all over the threads still also.

Valve seals, piston rings, puddle of oil in the plug galley seeping thru a bad sparkplug crush washer.

 

But it runs fine and no smoke at all?

 

 

i only wish that was true.

 

It is this. Put new plugs in and see how they look after a few days.

 

Hoping it's just this^^^. Then oil gets burnt.

 

sadly, galley looks bone dry.

 

Let's assume it was the last scenario.

unless and untill it's billowing smoke or consuming oil at a rate you don't feel you're willing to keep refilling.

If it was that you fixed the issue when you replaced the plugs. If it wasn't that you will start to see buildup sooner on that cylinder. Note pulling and reusing the same plug can damage/wear that crush washer.

A key factor, for this seepage, is the heat cycles. Dissimilar metals expansion ratios all that stuff, opens the threads and a damaged seal will allow the seepage.

Worst case in a similar fashion someone had to helicoil the sparkplug tap, now there are two places for seep and only one is covered by the plug washer/gasket.

..
Now if it's the other bits. A small percentage of 25% (one cylinder) down 10% is only (120/4=30*0.1=3) three HP on a fresh full power factory built 22re. You can lose that sneezing!

​​​​​​Small leaks don't accumulate while the engines running, same expansion principals in play, they soak into the micro layer of "normal" ash deposit and build over time. This wouldnt be any problem at all if they stayed attached, but what happens to the engine when that little chunk tries to exit at high velocity or wedges itsself agaisnt some of that aluminium. (Not all those divots you see are because someone broke a ring or plug)

Keep in mind there is always oil being burned in the combustion chamber, if there wasn't oil on all sides of the rings it's a bad thing (cylinder glazing). The crosshatch honing pattern holds oil for the rings to glide on, which is replaced with every stroke and consumed every fireing event.

The normal efficiency of combustion yields no smoke, so similar a small leak on one cylinder gets burnt by the heat from the other cylinders in the tail pipes. No smoke.

More problematic scenario! That cylinder gets the same amount of oil as the other but there is something wrong with its combustion (air fuel ratio, temperature of spark, or compression) yielding lower chamber temperature. Lower temperature means more unburned hydrocarbons and thus more built-up, and the potential for uneven expansion of head and block (warped deck, blown head gaskets).


Hope I didn't trigger anyone's anxiety disorders.

Bottom line is too much oil to fully burn at that cylinders temps. It could be too much oil volume, not enough heat, or just built over time.

​​​​​​​And for a freak curveball, could have been a trail fix and they had to use what was on the side of the road. someone pulled that out said "looks fine" and put it back in.

 

What is the best way to tell if it's rings or just bad valve seals? Compression test will just show either is the culprit and not pinpoint which one, correct? Leak down test?

 

Compression "tests" the compression with the valves closed, so leaking valve seals shouldn't have a major effect.

The biggest contribution from leaking valve seals is "overnight." The oil in the gallery above the valves leaks through to sit on the backs of the valves. In that scenario, you'll get smoke on start-up that quickly goes away.

I think L4wolvesf plan is the simplest. Replace the plugs, drive 500 miles, recheck.

 

Hard to make a judgement when you don't know how long that plug as been in service.

What happens to a new plug, and how long it runs before fouling will tell.

 

Put new plugs in drive a week see what you have

What did that spark plug boot look like ??

Some people can be quite sloppy pouring in oil.

The down side is not knowing how long the plug was in.

 

Boot & channel was dry. Plugs were probably in there a long time, however I do remember now that it did smoke for a second after starting it up after sitting for a while. But never had an oil smell and appeared white (not blue). Exhaust tip is not oily either. But now that I see this plug, I am thinking valve seals. Any downside to using the same valves or should I throw in new ones as well while I got the head off?

 

Just a through clean up, lapping in the valves (unless you see damage) and service on the rest should be good.