Raspy exhaust when....

[SHOemup]

When I first leave some place, whether the car has been sitting over night or for five minutes at the gas pump, the exhaust is raspy the first time i go through the gears. it's gets raspy around 3200 RPM.s which is the same area i have a hesitation. Any idea why my car is being like that? Thanks in advance.

 

[pete c]

my blk 93 mtx does the same thing. I think it's a blk 93 mtx thing. You could paint it? I am doing my 60k top end soon, hopefully it will help.

 

[SHOemup]

LOL, yeah, mine didnt do it when it was green wink

 

[smcallis]

But it goes away right? Mine does the same thing.

 

[SHOemup]

Yes, it does go away within the first or second time i go through the gears. It sounds beautiful after that but that raspiness just sounds bad.

 

[Ishodu]

Hey i got a green 95 mtx. it will do the samething but only on a cold engine. It goes away by the time I get to third.

 

[337]

I think it's a blk 93 mtx thing.

Maybe so, Whenever I shut the car off for even a couple minutes, then start her up, she sounds really raspy for a little bit, then goes away. I have no idea what it could be, but either way, I'm installing my performance exhaust system, and am doing my 120K soon. Maybe it'll help?

ishodu: was your car ever black at one point in it's life? That would even further justify this theory

Lee

<small>[ July 17, 2002, 10:26 PM: Message edited by: 337 ]</small>

 

[Blue95ATX]

Mine did it too for a while. Its probably your catalytic converters going, going, gone. Mine are all in my mufflers now and the raspiness is gone but now I have a surprisinly nice sounding exhaust, although a little ricey, still nice. Gets me noticed when Im driving I'll tell ya. Until I get my Borla mufflers and 2.5 cat back in a couple weeks thats the way it will stay.

If it is your cats, be carful not to let it sucked back into your engine through letting of the gas at "high" rpms or downshifting at "high" rpms. The cats end up being like sand.

 

[SHOemup]

well, I did the 120K about 6K miles ago and it didn't seem to help. I didn't do anything with the exhaust though. Oh well, if i dont have to worry about it and it's common on these cars, i guess i won't.

 

[pete c]

Not sure why I didn't think of this before, but, the chances are pretty good that you/we have a slight leak, probably where the manifold bolts to the y. After a minute or two of running, things heat up and expand enough to seal this leak. It is kinda annoying. Sounds like an older gm v-6 exhaust from one of their "sporty" cars like a z-24 or grand am. It is possibly the most annoying exhaust sound in the history of the automobile. BTW, while we're talking exhausts, I was under the rear of the car today mickey mousing a muffler hanger (the right side rear hanger broke from where it is welded to the muffler). The mufflers are dyno maxes. Are these good? Sound pretty mellow, but I don't think they are OEM.

 

[smcallis]

IMHO it's not any of the things that people have mentioned thus far. I just put on a SS Ypipe with cats...no change. I was looking forward to getting rid of it cause I thought it actually was the cats. No leaks either...I went thru a lot of pain sealing all the leaks associated with the POS ypipe and the rust holes in my muffler.

I supsect its the resonator. As I understand it the resonator is designed to do just that...resonate. It acts like a tuning fork to calm down certain engine vibrations that cause an audible noise (rasp). There is a strong resonance at 3700 or so RPMs and I think the resonator is designed to quiet it. You can actually hear it when it has "gone away" but it is a much more pleasing tone. What I dont understand is why you get that rasp on startup. It doesnt seem to be temperature related. As someone mentioned, you shut off the car for a few minutes and it comes back. BTW mine has done it for the entire 6 yrs I've owned it. Never gotten better or worse. When I start it I just get it over with. Wind it up in the first few gears and it's gone. I've convinced myself it's another "Feature" that gives the car its character. wink