exhuast noise - 1992 325is

[IvanB]

When i bought the car, it seemed noiser that I remember a stock 325is being,

clearly audible from inside the car with the windows rolled up, esp starting out from a stop.

The stock cat was replaced last month in an effort to get the car smogged(it eventually passed smog, barely) . after replacing the cat the exhaust system was still noisy.

I put my ear near the muffler and it sounded like noise was coming from that area, sooo I bought a new ansa muffler and had that installed today.

guess what... its even louder!

The muffler guy said that whoever installed the cat converter used an aftermarket one and its smaller than the original OEM cat, so he thinks the noise is not being dampened by the cat.

I asked him about a resonator and he said that my car didnt use a resonator and that the noise control came from a combination of the cat and the muffler.

has anyone else had this problem? do I have to use a stock muffler and cat to get the car 'as new' quiet?

I thought that mufflers made things quiet -- has anyone else heard of a cat being used to quiet an exhaust system?

anyhow thanks for the help!

[Furious]

mufflers actually can varry in noise depending on performance of the exhaust, the ansa muffler you got, is it a performance aftermarket upgrade?

[IvanB]

the ansa muffler is considered an OEM "comaptible" muffler. Its not a performance muffler upgrade.

it looks pretty boring, similar to the OEM muffler in size, its just aluminum instead of painted black like the OEM muffler.

[MyBimmer3]

I think the 92 325 does have a resonator because my '93 325is has one and im sure a 92 does too. what does this sound sound like? is it a raspy noise? vibrating sound? clicking? etc? give me an idea and i think i might be able to help ya help. because the resonator is the one thing you didnt look at yet i would look into that then if that doesnt fix it i would say its not fromt he exhaust, it could be ffromt he engine and is just being projected out the exhaust.

[MyBimmer3]

if it is a clicking noise it could be comeing from a stuck or partialy stuck exhaust valve or a exhaust vlave with a broken spring causing it to bounce instead off creating a good seal. there are so many things that create bad nioses and so many types of noises that you really need to describe the noise. in as much setail as possible. IM not an expert ( only 16) but ive learn alot form my dad so i might be able to help adn i can even ask him if i dont know it.

[IvanB]

The stock exhaust sounded like i had put a performance exhaust on, deep, raspy esp. at < 2000 rpm. Which makes it sound like a bucket when your stopping and starting.

At high rpm's the sound you cant really hear it over the freeway noise so its not too bad.

I had both the cat and muffler replaced with compatible new parts and the noise didnt go away, i got a bit worse , the new ansa muffler is raspier.

it interesting you say yours has a resonator, maybe they added one for 93 model year. Does anyone else have a resonator on there 92-99 ?

my guy said i dont!

[Kevin325i]

I don't. And mine is loud as you said, but I like it that way.

Kevin

[BMWg84]

92s are naturally loud because of the aggressiveness of the exhaust camshaft. We lack Vanos, so our "hot" cams make up for the needed horsepower/torque. I recommend getting an M3 exhaust. ANSA will still give you a loud note because it's very free-flowing. The M3 exhaust is packed with sound absorbing materials and chambers, which will allow for a more subtle sound.

[IvanB]

thanks Chris, appreciate the suggestions, I saw a m3 exhaust for sale on ebay pretty cheap, from a 96 i think. the bolt pattern looked similar.

[greennvmachine]

it is always possible that you have an exhaust leak as well check your manifold and gasket

[Kevin325i]

'92s represent. We've also got larger valves.

You wouldn't happen to know the specs on both the intake and exaust cams would you?

Kevin