2013 Mazda 3 2.0 Skyactiv
I was informed that my hydraulic belt tensioner appears to be leaking oil and should be replaced. I also noticed similar oily/gunky buildup in the area by the tensioner.
Photos: https://imgur.com/a/1eJRw4x
Questions:
Photo #1: Does this definitely look like the tensioner is leaking oil and needs to be replaced? I wiped it off to monitor it.
Photo #2: Is the same oil/gunk buildup in the area next to the tensioner from the same source, i.e. all related to leaking tenisoner? Or is it a sign of a possible different issue?
Possible relevent background info (photo #3):
I had a minor oil leak from the oil control valve/solenoid seal that is on top of the engine valve cover and I had the OCV seal and the valve cover gasket replaced three months ago (apparently this a common issue/repair for this engine). I have been monitoring the OCV and it doesn't appear to be leaking anymore. I'm not suspecting this current gunky area is related to the OCV leak as I don't see any oil trail from the engine valve cover area to this area.
I definitely replace the tensioner but you never know with oil leaks so I would put UV leak detector in the engine oil and then see where the dial leaks out it glows green with a UV light after you drive it wherever a leak comes from
Thanks Scotty. I also posted this on reddit and a Mazda mechanic recognized and confirmed the tensioner is bad; he also said the additional oily area is not related to the tensioner leak but is because of a bad timing cover. Apparently both of these issues (especially the tensioner) are fairly common issues with this model/year. He said the timing cover leak doesn't look that bad and doesn't need immediate repair (he said probably ok for at least 10k miles), so I'm going to wipe the area clean and monitor it and perhaps add some dye as you suggested.