My 2008 (97K miles) sounds like it has an exhaust system leak somewhere-- very audible engine rumbling whenever the ICE is running. The sound first started a couple of months ago, not loud at first, has been slowly getting worse. Otherwise the car appears to be running normally, no significant change in mileage performance. Would it be reasonable to take the car to a chain muffler shop (Midas, Cole, etc.) or should I stick with the dealer (which I assume would be more expensive)? Any advice appreciated.
Yeah any muffler shop can handle it. Its just good old exhaust pipes under there. Most likely the connection at the bottom of the exhaust manifold has come loose. There's 2 bolts that are spring loaded. Just need to tighten them a bit. Mine came a little loose too. Or you have some serious rust issues as I see where you live and have a rusted out muffler. Takes 5 mins to figure that out. Do like I do and take advantage of the car on a lift and duke the tech a few bucks and ask him if ok to look under the car yourself and inspect front and rear suspension for any bad rust issues. If anything you don't like take a picture and post it.
@prius_cub here in Virginia recently reported his manifold upstream of the muffler was rusted thru...think he DIY'ed a fix ..he posted some pics. Have not heard too many cases but I guess winter salt could be a culprit. 2008 Loud Engine Noise | PriusChat