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I'll post here as most users here have reasonable (trusty) answers, or suggest a good forum.

A friends 1986 PU failed the Cal visual smog due to high/excessive tail pipe blue smoke, it passed the general HC, and CO test, but failed the visual of the tail pipe. We did compression test 175psi +/- 5psi on all 4 cylinders.

I suspect leaky valve stem seals, at 250Kmiles, but the spark plugs look decent. The design of this engine requires to change the headgasket as the rockers bolts are also the head bolts, some forum users have succeeded in avoiding the headgasket replacement, but it seems risky.

Here are the spark plugs as pulled out on the right side and after cleaning them on the left... we should have replaced them, but this is remote sierras location... the nearest town is 40 miles away!
thank you and Happy New Year

My son has one. What a questionable design when you have to do some kinds of work on it.

I assume he took it out for a good long freeway drive before the test to cook out the exhaust system?

Maybe run some 20-50 oil for the test?

Straight 50wt is available as Valvoline Racing Oil. If you are going to go with a heavier oil, you may as well better your odds. 50wt is ok in California; no need to change it right away - many ran it in tired engines when I worked at a parts store in Santa Ana. Change the PCV valve? Maybe there is some way to isolate leakage through the valve seals versus through the oil control rings? With good compression, those seem like the only ways oil could get into the combustion, other than a head gasket failure or a crack in the head. Leak down test maybe? Listen with a stethoscope?

Rebuilding the head on the 22R/RE isn't that difficult.

If it is valve stem seals, it needs to be run for as long as possible before the test. It should burn up the oil that leaked into the cylinders while sitting. Unless they are so bad that they are actively leaking while running. But that would have to be pretty bad.

https://www.walmart.com/ip/Dorman-46110 ... 1995952232

This helped the SJ and ZJ with oil consumption a fair bit--AutoZone has them at pretty much every store. Might be enough to get it through emissions, although Idk if Cali likes those tanks.

Otherwise replacing the valve seals is the best bet I know of, unfortunately.

sierrablue wrote: ↑Tue Jan 02, 2024 8:23 pm https://www.walmart.com/ip/Dorman-46110 ... 1995952232

This helped the SJ and ZJ with oil consumption a fair bit--AutoZone has them at pretty much every store. Might be enough to get it through emissions, although Idk if Cali likes those tanks.

Otherwise replacing the valve seals is the best bet I know of, unfortunately.

That will help a lot if the oil is coming through the PCV.

Yeah, if you can find a place to hide it so it passes visual if the inspector's a.

But with compression like that he shouldn't have much blow-by. Maybe the compression gauge was a little optimistic?

I assume it doesn't use oil since it wasn't mentioned but good compression doesn't guarantee good oil rings. So, along with the heavy oil, run it low. I think it takes four so running only two would prolly be safe for the test.

Thank you for all the ideas, will pass to the owner. in fact it is using oil! The air filter enclosure is dry, no oil pooling.

It is smoking quite a bit on acceleration with new 15w40, my friend realized that there was at least 1 quart of oil missing from the oil change a few days ago. The drive to town of 40mins is enough to have the engine warm and toasty.

PCV was tested, carb is sucking ... there was no real changes in idle or acceleration when I pulled the PCV out of the valve cover, with 250k, not too sure what will be found under the valve cover!

No rush, it is a remote area, will probably do the seals when the weather cooperate, after getting the parts.

quick update, the owner decided to try some of that honey oil, which helped pass the visual, no smoke, but failed the HC and CO at the 2500rpm pre-test

High HC and CO likely means a failing catalytic converter. And its most likely failing because its filled with carbonized oil.

Odd that it passed before. What else did he do to it? Again, take it on a long drive to heat the cat up.

Did he try any of those magic fuel additives that are supposed to help you pass? They're gair-un-teed.

SJTD wrote: ↑Sat Jan 27, 2024 12:17 pm Odd that it passed before. What else did he do to it? Again, take it on a long drive to heat the cat up.

Did he try any of those magic fuel additives that are supposed to help you pass? They're gair-un-teed.

Yes, he did put some cleaner... not too sure which one! It may be a few weeks before we "me" look at it .... Most people are not too inquisitive when going thru the smog test. This last one was a pre-test, so no numbers were given, the tech said both HC and CO in the red... The drive to town is a good 40mins, so all systems are up to specs.

As a little note I went thru the smog with the 85, this is a test on the roller, the idle HC and CO were a bit high, but the tech said that the system does check for the idle numbers, it passed easily, albeit a bit higher than 2 years ago.... the choke seemed to stay a bit too closed, when I checked back in my driveway...

thank you for the ideas

Not just hot but cooked out. I wonder why he passed the first time.

The stuff I refer to isn't a cleaner. I think It's supposed to be in the fuel when you test. Might be just alkyhol or some kind of oxygenator. Seen them in the stores but never looked at one.

He could not remember what he bought.... Max something.... this is why I am helping him, and he helps me with electricals, he needs to fix my oscilloscope