Today I noticed a popping sound while cruising at highway speeds that I could feel at the firewall. It was kind of random and sounded like a very muffled backfire. So what did I do immediately before that? I jacked up the car and rotated the tires. While doing that I also checked the front calipers for a noise that I had been hearing. A scraping after braking and during breaking while coming down an occasional very very large hill. As part of my exam, I pushed in the caliper pistons a little to be able to move the caliper and check for binding. All OK... Turns out I think it was a rusted dust shield. I pushed that back a little and the noise seems to be gone. Not sure what this new highway noise is. Prius has 225K miles. 2007. I checked for loose plastic underneath and nothing apparent. At less than highway speeds it drives fine and is quiet on turns and while braking.
Just a follow up. The noise and bumping under my feet happened this morning on my way to work. A 10 mile drive where I am on the highway at 65 mph. After getting off the highway I drove another 4 or 5 miles with speeds below 50. No noise on the drive back at noon it the same 10 mile highway run. This time nothing unusual. I am away from the car for the weekend but I plan on putting it up on ramps to see what’s going on when I return
When you get the bump and noise, do you by any chance also get a amber light on the dash for traction control being active? Posted via the PriusChat mobile app.
I didn’t notice any dash lights or warnings with this latest issue the car does have an issue while braking if I run over rough roads the traction light may come on and the brakes feel like the let go momentarily. Never found a solution to that. Been happening for years
Just drove up on ramps and nothing unusual stood out. I did notice it looks like my exhaust gasket is worn. I wonder if this could be the cause of my noises. I have had a cat efficiency code on and off and this would probably qualify as an exhaust leak although it’s not loud
Nice find, but I'd say 'gone' instead of worn. It should be a carbon donut. That gap is where some of it used to be. I have seen cats clogged badly enough that at higher power levels, the pipe will lift off the gasket to relieve pressure, kind of like a pressure cooker. Pounds the heck out of the donut gasket.
Right. Gone is a better description I don’t have drivability or mpg issues yet so I would be surprised about the cat being clogged but who knows.
From Post #1: Today I noticed a popping sound while cruising at highway speeds that I could feel at the firewall. It was kind of random and sounded like a very muffled backfire. Not sure what this new highway noise is. I would say you have your answer... and this: the car does have an issue while braking if I run over rough roads the traction light may come on and the brakes feel like the let go momentarily. Never found a solution to that. Been happening for years has been happening to not only you, but every owner of every Gen 2. Pretty much standard operation of the Gen 2 traction control/abs. Nothing to worry about.
The gasket may be self healing because the car has been driving better than ever. I actually had some sounds that were like pinging under hardly aggressive driving prior to this incident. Drove 90 minutes on highway and hills, got 48.5 mpg. Then when I was driving locally, the red triangle. I thought maybe a door open... but no. Damn I should have that scanner with me in the car. I noticed the air bag light on, check engine light on. I moved the car a few miles to another parking lot and got out to leave it there. Noticed a puddle below, went back and moved it back.. just water from A/C. moved back into the space. The triangle and check engine light were off. I was at a work site, so I got a ride to the hotel. Going to see if I can hookup a code reader in the morning. Seems like with 225K and 15 years, it may be suffering from old age. I haven't replaced the gasket yet because I have read reviews that no aftermarket gaskets will fit over the converter.
