Why does my 2010 I4 sound like a tractor?
2010 Venza 2.7L I4 AWD. The video is a couple months old but it still makes this noise. The best way I can describe the sound is a tractor-like rattle, kind of a repetitive, clattery noise. It is most noticeable at idle, and doesn't really seem to get worse with acceleration. I just barely changed the oil and added some stop leak stabilizer as well. And it still makes this noise. It has been doing it for at least a year, maybe two. There are no warning lights or anything, and all systems work as they should. I'm just wondering if I need to be concerned, or if it's old engine stuff. The car is just about to roll over 270k miles so I don't really think it's worth obsessing over and throwing tons of money at. But if I can save myself a big problem in the future by replacing something now, I'd much rather do that.
I'm mainly thinking it's either the valve train or maybe the AC pulley. If the AC pulley goes bad, could it affect the rest of the serpentine belt or would the ac just stop working?