A few days ago, I decided to help a few friends with this AP1 S2000. After burning up to a quart of oil every 800’ish miles, they were asking me to see what was wrong with it. Even my SR20DET doesn’t burn oil nearly that fast. Something was up with the S2K. So, I figured, why not do a leakdown and compression test?
Tools of peace. One thing is for sure, it’s a lot easier to turn the crank from above the engine bay on an S2000 than it is with a 240sx with stock fan clutch. On a 240sx, you have to turn the crank from under the car, which is kind of a pain in the angus. S2k, you can do it above — nice!
Just when I was about to start, I turned on my little compressor from Harbor Freight, and it was leaking. Apparently, the drain valve’s o-ring was broken, so it was on constant drain. Luckily, I had some leftover paintball gun o-rings, and one of them fit to repair the valve! Sweetah! So, the compression test numbers were roughly equal, around the 135’ish range. From what I understand, it’s a bit low for an S2K. I poured a cap of oil into cylinder #1, and the compression shot up a bunch, which means the rings may be going. The leakdown test showed about 30% leak across the board. So, what does that mean? It means the engine is getting a little tired, and it wouldn’t hurt to start saving for a rebuild.
As a thank-you to my fine work, I was treated to some fine dining at the local Mexican Restaurant, called Luna’s. Really really classy. You see the look on this guy’s face, sitting on the donkey? That was my face the whole time in the restaurant because it was THAT pleasant.
How’d you figure that putting in oil, and compression numbers shooting up possibly results in bad rings. I’m trying to put two and two together for future reference.
The oil acts as a film and improves the sealing between the rings and the cylinder walls. This works mainly if the rings themselves are going a bit bad or are getting worn out. If the rings are in otherwise very good condition, then the addition of oil into the cylinders won’t make much of a difference.