Morning All
A recent conzult power balance test highlighted an issue with No. 6. Despite this, car was running fine. Anyway, decided to change plugs yesterday for the cooler NGK PFR6B-11B's. No 6 plug had some oil on the end and evidence of a burn mark. Other plugs and all coilpacks were fine. Did a dry compression test and cylinders 1-5 showed 165psi but no.6 stopped at 90psi :sad: Re-tested and same readings.
As I said, the car seems to run fine - no hesitation, misfire etc but clearly there's a problem as there should only be a 14psi maximum difference between the cylinders. A little research suggests that as there is low compression on a single cylinder, it may be a broken ring, burned valves, or a burned piston.
1. If it was any of these items, would the car still run without any notable issues? If not, what symptoms should I be encountering?
2. If left unattended, what potential issues can I expect?
3. Other than a wet compression test, is there anything elseI can do to diagnose the problem?
Thanks, any thoughts or comments would be really appreciated.