I have not performed a compression or a leak down test. I'm going to try to perform them soon also a friend is supposed bring a boroscope(?) to inspect the piston chambers. Engine oil is Castrol Edge high mileage 5w-30, usually changed every 6 months as i hardly do 1-2k miles per year.

What are the methods to inspect valve stem or guide seals?

 

Consistency and nature of that smoke, it's oil. What is your current oil consumption? Leak-down test maybe the best, cheap test to attempt. It's prolly oil rings or valve stem seals. Or both.

Good luck with the fix!

 

^^^ yep

Low mileage would not correlate to worn guides, but age could correlate with bad valve stem seals. Even a late 2002 is 19 years. Not like that's a common thing around here, but if the engine saw extended oil change intervals with crappy oil or sat for long periods, it's possible the seals are failing. At 54k now 19years later, who knows, maybe it didn't see much use or was put into storage at some point.
Another possibility would be switching oil types/brands. Kind of like the thing where people are scared to switch to Syn from Mineral on a high mileage engine thinking it will cause leaks (I did this on my wife's MDX @ 179k miles; almost immediately it developed a RMS leak). The various seals in the engine become conditioned to one oil type/additive package, and then sometimes switching can shock the seals, causing elasticity issues etc.

Here's a valve stem seal DIY. To inspect properly or replace, valve springs have to come out. Great time to do those AP2 retainers though!
https://www.s2ki.com/forums/s2000-un...t-diy-1170027/

A borescope can be pretty cheap, or pretty expensive. If your buddy has one with an articulating head that'd be better. I have a cheapo from Amazon that displays onto your laptop...crappy resolution, non articulating. At work we have a high end one ($28k) that we use for inspecting aircraft engines...that's just the scope. The various tips cost between $5k and 10k each. It's insane what it can do. You can snake your way into an impossible spot, photograph a defect, freeze frame it and measure it to 0.001". Pretty cool. And they have better ones capable of 3D modeling for depth measurement...wow.

 

Where is your oil level? Up to the H? In the middle?

 

Thanks to all of the comments. Billman, I try to keep the oil level just below the high mark, measured on the driver side of the dip stick.

I pulled out the spark plugs and they all have oil residue. If it was a mechanical failure such as valve stem seals or piston rings, wouldn't the all 4 cylinders having the issue seem highly unlikely? Perhaps its some sort of crankcase ventilation/pcv valve issue that is effecting all of the cylinders? I did remove and wiggle the pcv and the ball within it shakes freely.

And here it gets even more confusing. I possibly have fixed it, at least for the time being. I changed the oil in preparation for the winter storage and after driving for a while the smoking is gone. Did the old oil thin out and was somehow making its way into the piston chamber and burning?

 

What is your PCV setup? Have you tried replacing it? Sounds like a lot of burn off to just be that but worth a check to see if crank case pressure is high.

 

If your old oil had a lot of moisture in it, it may have been causing the smoke.

Maybe you make a ton of short trips and the oil has been in there forever.

Still very strange that an oil change cured it.

BTW, one of your plugs looks much more sooty than the rest.

 

The far left spark plug is the only one looking oil-fouled. The far right looks like that cylinder was burning rich. Two in the middle don't look bad.

 

PCV set up is an 04-05 valve cover with the 04-05 OEM PCV. Hose routing is OEM. There is no catch can. And yes, the car for the most part only sees short drives. There is no misfire code at the moment but I'll look into replacing the spark plugs soon before it becomes an issue.

Would vacuum caused by decelerating with the car in gear cause the oil to be sucked into the intake manifold?

 

Could send your oil to get tested