Question for car mechanic about oil filter.
just changed oil and oil filter in Mazda 2 diesel for 1st time. same engine as fiesta 1.4 tdci. All went to plan, but when I removed the oil filter cap I am sure that there was no old o-ring fitted on the cap. The new filter came with a new o-ring in the box, but when I tried to tighten cap with o-ring in place it was impossible to do without the o-ring coming out of the groove. The new o ring seemed a bit too big for fitting into the groove also. My question is ...as the car didn't appear to have one fitted before I should be ok to tighten up with one missing? I ran the car engine for 5 mins with no leaks.