I recently purchased a 2007 Subaru Outback 2.5i, with approx 146000kms on the clock.
As its a recent purchase, I'm going through preventative maintenance to ensure its running as good as possible.
One of these measures was to get my mechanic to carry out a cylinder compression test and a cylinder leakdown test.
Here are the results of these tests:
cylinder # | comp ----------------- 1 | 200 2 | 200 3 | 205 4 | 200
cylinder # | leak ----------------- 1 | 10% 2 | 8% 3 | 12% 4 | 18%
My mechanic says that all of these results are normal and within specs except for the cylinder 4 leakdown which according to him is leaking into the oil filler tube, which he finds very strange and has no explanation for.
Could you please help me understand these results, in addition to what my mechanic said? What do they mean? Also, do I need to worry about these results or take any additional actions?
- A cooling system pressure test was also carried out and was found to be all ok and within specs.
- A block chemical test was also carried out and was to be all ok and within specs. I don't understand what a block test actually is so I'm not sure what this means.