Weird Noise under Car?

[ConElite]

I have started to notice that if Im in about 1st or 2nd and I get on the Gas, The car makes a Whirl Noise under the car. Almost sounds like A spooling Turbo or S/C. It only does it when I get it above about 3800RPMs. Cars Stock. I checked all the fluids except the trans but I highly doubt it low. I really dont know what this can be. Can it be exhaust related?


Any help you guys can give me would be great.

[Joe 1320]

Does the whine go away when you take it out of gear? Does it increase in pitch with the engine, or increase in pitch with driveline speed?

[ConElite]

It Almost sounds like Pressure escaping from the exhaust. Its only if Im in gear (1st or 2nd) and Im excelerating in a rather qucik manner. Almost like a whisle. The pitch does not increase the higher the RPMs go but it does get a tad louder as speed increases.

[99Firebird3800]

I've heard alot of manual transmissions start to whine as time goes on, and some of them sound JUST like a turbo. Typically in F-bodies too, ironically. It's just normal I think, because I've pulled 'em and torn 'em down and found NOTHING wrong, put it back together and the noise is still there.

[RAF7789]

I remember that problem with my car right when i got it last year. It went away when i changed the tranny fluid. It is hard to tell exactly what it is from a description.

Hope this helps

[Injuneer]

Plugged cat(s)?

[ConElite]

Plugged cat(s)?

You think so? That would result in over-all power loose no?

[Injuneer]

Definitely reduce power at the top end.

[ConElite]

Well In all Honestly the power is not as "Crisp" as it used to be. I mean it still whips my head back but it seems like it lost a little Pep in its step if you catch my drift. I never tought about the cats. I do recall there being something about the Cats the the 98-01 F-bodies being defective.

It does not sound like its mechanical at all.

Is there any way I can check to see if its the cats, and what should i look for?

If thats it, Its an excuse to buy a "RandomTech Y-Pipe with high-flow cats."

"But Dad, I need to spend $600+ on this, It needs it!"

[Injuneer]

You have to pull a pre-cat O2 sensor out, and attach a pressure gauge to measure the pressure in the exhaust system. Both sides would need to be checked. A muffler shop would probalby have the correct gauge, and would know the specs for the correct pressure.

[ConElite]

Thats the only way? Damn, I need to start my search for a shop with the ability to do that.

[RAF7789]

....
If thats it, Its an excuse to buy a "RandomTech Y-Pipe with high-flow cats."

"But Dad, I need to spend $600+ on this, It needs it!"

I think all aftermarket cats are "illegal" (in Cali) on OBDII vehicles b/c all of them are "High-Flow".

I do not know how they check for "High-Flow" vs "Low-Flow" ( );
however, i have heard of people getting away with it....

[ConElite]

My brother runs a Random-Tech y-Pipe on his LT1 and he passed no problem. As long as you dont relocate the cats your fine I think.