2012 Mazda3 171,000 miles Is this normal clacking noise for a high mileage Mazda or do I need to take it to a mechanic?
Hard to tell off the video. If you are worried about it, take it to a mechanic. In person it would be easy to diagnose.
After listening to some examples on the internet of what rod knock sounds like versus just normal engine ticking, I'm pretty sure it's just engine ticking and not rod knock. My Mazda 3 continues to do the not die.
With the hood closed it's hard to tell. even with it open it would be difficult to tell. @Mod_Man said it, if you're worried, bring it to a mechanic and have it diagnosed.
The way camshafts are geared they rotate at half the speed of the crankshaft on a normal 4-stroke engine.
Relatively slow ticking is usually a valve tap and not destructive unless very loud. Engines will run for years and years that way, though on cars like Hondas with manually-adjusted tappets it's an indication they should be adjusted. The noise will vary with engine speed but not load.
Rod knocks are deeper, faster noises and when really bad you can feel them. Knocking will increase under engine load. Rod knock means an engine rebuild is required or it will self-destruct in short order.
It seems not to be rod knock. I am 99% percent sure. I would take it to mechanic just to be on the safe side.
