First time doing a compression test. Apologies for noob comments during the video : ) Cylinders 1, 2, and 3: 210 psi right away Cylinder 4: 170 psi After adding a capful of oil to each cylinder, they all go up to between 225 and 250, with the 4th cylinder at 235. The things I'm reading say piston rings are worn. The difference between the first 3 and the 4th is 40 psi. The difference after adding the little bit of oil is +/- 12.5 psi across all 4 (less than 6% variation, or 10% from highest to lowest). So the question is, is it bad enough to warrant an engine rebuild? I used to get 36 mpg freeway now I'm getting 30. Some of that could be due to other problems though. Comment away!
compression, test, worn, piston, rings, saturn, sl2, 1994, psi