Hello,

I have a 97 Honda Civic with about 150,000 miles on it, I bought it a year and a half ago and have never had a problem with it, keep up oil changes and have a full histroy of service work done on the vehicle. I am by no means a mechanic so when my car started to make this buzzing kind of noise a couple of days ago I got alarmed. It happens when I am i shifting in lower gears and it is almost like a rattle kind of sound. When I get going it seems to go away and it is not there all of the time! Does not seem to happen in reverse and the car seems to run fine except when I am trying to pass or go up a hill it seems to have lost a bit of power? I am not sure what to believe when I go to a mechanic because I have been burned by them in the past so if I have a good idea of what it is before i take it in I would feel much better about what they are going to be working on, my muffler seems to be louder now as well? Any help would be much appreciated!!

 

Do you have a check engine light? When you first start the car, does it turn on then off?

As for the louder exhaust, it's possible that your exhaust has rusted out or that you have a loose heat shield. That could account for the buzzing/rattling. Things resonate at different frequencies so when you shift gears, you might hit that frequency.

 

Sound like a bad muffler could be indeed a bad muffler, or a hole somewhere else in the exhaust system. Idle the engine and block the tailpipe with a rag. If there are any holes, you will hear gas hissing out of them as the pressure builds. On the models other than EX in that year range it is real common for the manifold on the front of the engine to crack.

 

+1 on the cracked manifold. I just did mine earlier this summer. Called around to junkyards, hoping to find a non-cracked one... no such luck. I heard from a few places that the few that DIDN'T crack early in their lifetime are very quickly stripped off the junk car and installed on someone not wanting to pay for a new manifold. Needless to say, I had to buy a new one...

However, replacing the cracked manifold restored some fuel mileage and cleared up that pesky CEL that stared me in the face every day

As far as rattle, about a year ago I had to replace the spring bolts a little further back from the manifold. They had loosened off and the exhaust would rattle at idle, but not at 1000rpm or above. So that's another think to look into