After downshifting, engine is very loud

OK so I have a 2000 Toyota Camry with 120,000 miles. The car was quiet as can be; it was great. Just today, I was coming back from a long trip (210 miles) with the cruise control set at 60 MPH. I came to a moderate hill, and I guess the car felt the need to downshift 3 times to maintain the speed. Was in 4th gear, then 3rd and 3,000 RPM, then 3 seconds later 2nd gear and 4,000 RPM, then another 3 seconds later 1st gear and 5,000 RPM. A couple seconds later I crested the hill and gradually got back into 4th gear. Since then, there haven’t been any performance issues, but now the engine is very loud; it sounds like a hot rod with one of those engine-sound-amplifying tailpipes. Any ideas?

You need to get the exhaust system inspected. Just a guess here, but be prepared to replace the whole thing from the manifold back, including one or both catalytic converters. One of the catalytic converters may have gone into meltdown, blocking the exhaust and causing the power loss, until something gave way and now the exhaust leaks somewhere forward of the cat at fault.

While I don’t believe it is possible for the cruise control to stay engaged and the transmission to shift all the way into 1st gear - your story is your story. My 2000 Camry (a V6 motor) would cut off the cruise if the speed got below 30 mpg. So, if you were still going over 30mph and in 1st gear you’d be running the very high rpm’s you indicate. This must have been a very steep hill.

All I can imagine is the motor was putting out much more rpm than normal and perhaps your blew a hole in your exhaust system. A 2000 Camry might just have an old exhaust pipe, or connection, that was ready to give out and the high rpm and volume of exhaust did the trick.

Wow…would the car be safe to drive after something like that?

There is the issue of exhaust fumes getting into the cabin and that could have some safety and medical issues. If you drive with the windows down, you should be able to make it to the garage to get it repaired.

Not sure if it makes any difference…I did not hear any abnormal sounds at the time of the incident, and since it is bitterly cold, I had the windows closed, and I smelled no fumes or anything for the remainder of the trip (about 50 miles).

I think you had an exhaust restriction, possibly in the catalytic converter or muffler and the engine finally blew through it, causing a hole somewhere in the exhaust system, forward of the catalytic converter.

Yikes…how expensive could this be to repair?

Your car is now 10 years old so be ready for some more expensive repairs. This could be expensive or cheap and it all depends on what came apart. Perhaps a couple of pipes that are in good ahspe just came apart due to a clamp that rusted out. Or, perhaps you just blew out the muffler and the other pipes are ok thet will be about $100. If as I suspect the majority of the exhaust is just old and about to fall apart you may need a new muffler, and some pipes too. If the cat is OK then less than $500, more if the cat is bad.

All you can do is take it to a shop where you think you’ll get a fair price and see what they say. Since the car is driveable I’d get quotes from a couple of places before deciding who will gets to do the job.