I have a 94 Firebird with 3.4L V6 (automatic). Whenever I accelerate while driving in city traffic, the engine makes a rather ugly farty noise. It sounds kind of loud, but the loud which is bad loud, not good loud, if you know what I mean. What I am hearing does not reflect the sound of a power, rather it sounds annoying and similar to sound of clearing your throat. I reaize it is only a V6, but a friend of mine had a 94 Camaro, and the engine sounded alot nicer, quiet, etc. I am not sure of the noise I am hearing is normal for an auto V6. I have had the car for a year now, and I haven't owned a V6 Camaro/Firebird in the past. I changed the muffler to a Borla, which sounds nice, but still, when I drive it, the sound of the engine seems to monopolize the interior cabin. I had the muffler shop do a quick visual inspection of the manifolds and pipes, and they reported no irregularities. Does anyone know what might contribute to the sound I am describing? I don't hear any hissing or anything like that. Its just that when I press the gas and the engine accelerates, it sounds like a #$@ lawn mower farting along. Seriously, it is starting to **** me off to the point I am considering selling the car to buy a V8, a rather drastic solution. When I first bought the car, this sound quality didn't stand out and I didn't notice it at all. Now, as I am becoming more and more interested in performance and powe, it is really starting to bother me. It's almost embarrasing when I press the gas on this bird.

Thanks folks.

Any advice is appreciated, thanks!

 

do u have any holes in the exhaust? also what kinda of condition is ur Cat in?

 

According to a recent muffler shop visit, I do not have any holes in my exhaust. My muffler and tailpipe are brand new. The cat is in rusted condition, and doesn't look like its been changed for the life of the vehicle. I haven't done any tests to determine the integrity of the cat, but there is no obvious damage to it. The noise is coming from the front of the vehicle anyways, it doesn't seem to be positioned in the area where the cat is located. Do you think a bad cat might contribute to what I am hearing?

 

The most likely culprit is the catalytic converter from what you have explained. Go make a friend and have them work the gas pedal while you listen under the hood. If the noise is coming from the front, and your exhaust is in good condition, then the noise should be found in the engine compartment. Another possible culprit is a leak at the manifold, so your focus under the hood should begin there.

 

You are exactly right about the manifold. I was in the muffler shop this morning getting a high flow cat installed, and the mechanic there heard an irregular hiss or noise coming from the passenger side manifold. They suspect it is either cracked or something like a broken seal or bolt. Without me agreeing to pay money to let them start taking things apart to do a close up problem diagnosis, I do not know exactly what it is. However, they highly suspect the manifold as the culprit. Great. Right after I spend my #@$ money over the weekend to install a Borla muffler and magnaflow cat + 2 oxygen sensors (mine were totally rusted out and not working correctly). Now this maifold issue is going to cost me. What a #$@ depressing thought taking into consideration the financial hit I just took in the last 72 hours. Any words of advice before I throw myself off the nearest bridge?

 

Glad to hear that we got on the right track. You have a few choices with the manifold. First, you can replace it. You can either buy one new or a used one from a junkyard. I would recommend used if you choose this route. Also, you can attempt to weld it to repair it if it is cracked. It may just be a broken/loose bolt that needs replacing. That should not be expensive. You can also suck it up and deal with it. There will most likely be little performance loss, it will just be loud. Finally, you can purchase aftermarket headers. Personally that would be my take on the situation, as spending money might as well be an improvement. And the cost of headers will probably be not much more than getting a stock replacement completed. Keep an eye out on ebay and the classified section of this site and V6 camaro specific sites and you might catch a really good deal.

If you throw yourself off of that bridge, can I get your car?