Hi folks,

Just purchased a new-to-me 86 22RE engine in a 4runner and got a compression test done.

Results:
1, 3, 4 - 150 PSI
2 - 125 PSI

The test was done with a very cold engine (been sitting for 2 days).

The mechanic shop didn't think it was a concern for an engine that age and, at operating temperature, would likely seal up even better.

Thoughts?

PS - I'm about to drive this 3600 miles cross-country and operate it on the very remote Nevada desert floor for a month. 😅

 

I’m sure it would be somewhat better warm. Mine tests low on cyl 4, but you wouldn’t guess the way it runs and still knocks down 21-22 mpg on the highway. I put engine restore in it but have not done another comp test yet. Drive it.

 

Rule of thumb is within 10% of highest and lowest reading.
I assume valves are adjusted properly?
If you do a dry and wet compression test, and see an improvement when the wet is done, that generally narrows focus on rings.
You may have just sludged rings. You could try changing the oil and filter and adding a cleaner like Rislone to the oil, then running it. You'll have to do another oil change in 500-1000 miles to get the cleaner and dirty oil out. If you do run a cleaner to the oil make sure to check the oil level frequently. If the level drops while cleaning that's normal, just add some more.

 

A friend of mine, a professional mechanic by trade, told me you could get your vehicle warmed up real well, shut it off, and pour a small amount, about a dixie cup worth, of diesel fuel into the oil. Run it for 4 or 5 minutes, certainly no longer, shut it down, and drain out the old oil. Put a new filter on, new oil in, and voila! The inside of your engine, including the piston rings, will be much cleaner.
Be careful, changing the oil of a hot engine can be dangerous. You can get burns from hot oil, and hot metal on the vehicle. Just be cautious. I used to do a "hot oil change" ever third or fourth oil change. Having over an hour's hiway drive both ways for work piled the miles up pretty quick.
Apparently the diesel helps break up the crud that builds up where the oil goes in your engine. Then, it all flows out with the old oil. I never tried it, but he swore by it. Did it every oil change he did. Seemed to work well for him...

Pat☺

 

I could see that working. The real old school guys would drain the oil and replace with atf, then run for a few minutes. But that’s too edgy for me. Fine line between thoroughly cleaning and destroying.