Sick of this rattling!!please help!!

[3.4grapeofwrath]

Re: Sick of this rattling!!please help!!

Buy yourself a small fuel pressure test gauge from any auto store and connect it to your fuel rail. Most of them have a length of hose you can tape it to your windsheild and go for a ride. Watch the fuel pressure under engine load it should go up if it doesn't you might need a new fuel pump. If the pressure is correct it could be a bad o2 sensor reading incorrectly causing a lean condition. This might be why when the car is cold it does not happen the ECM goes into open loop when the o2's are cold. You could even try disconnecting the o2's and taking it for a ride to see if the problem goes away.

[LEOMAC23]

Re: Sick of this rattling!!please help!!

If it was the O2 sensor wouldnt it throw a code?? I am definitly gonna pick up a feul pressure gauge tho

[jarashto]

Re: Sick of this rattling!!please help!!

I experienced the same deal with my 99 Camaro 3.8. At first I thought it was the cat and I was already going to replace it and run duals out back. The cat didn't fix it. Came to find out, it was my Y-pipe. It's dual layered and would rattle at real low rpms under acceleration. Did a few spot welds to attach the inner layer again and it was fixed. Try holding your foot on the brake, shift into drive and gradually pressing the gas until you reach 1300 to 1500 rpms. That's when I heard the noise and come to find out it is a common problem with the 98 and up Monte Carlos, Impalas, and Camaros with the 3.8.

[LEOMAC23]

Re: Sick of this rattling!!please help!!

Thats what i thought it was too but this rattle goes away if the car is shut off then turned back on and i think an exhaust rattle would be there all the time

[LEOMAC23]

Re: Sick of this rattling!!please help!!

Hey i think i might have solved me rattleing noise, after just pouring some seafoam into the brake booster i notice that when it started to stall white smoke came out of the bottom of the exhaust manifold, could this be my rattling noise?? and would an exhaust manifold leak only when warm and under load??

[ssms5411]

Re: Sick of this rattling!!please help!!

That would be your exhaust leak, and your noise your hearing, get some fel pro metal header gaskets and what I use is copper spray sealant. I spray the metal gaskets with the copper spray, let them sit for about 30 min. to a hour and then install them. They have 2 slots on them where you can leave 2 bolts in. Then just slip the new gasket in and tighten down. Then once done on both sides just let it heat up real good then after it has cooled down retighten the bolts. I would then recheck them a few days later then about a week or 2 later. Then you should be good to go on checking the bolts.

[pace2006]

Re: Sick of this rattling!!please help!!

Hey i think i might have solved me rattleing noise, after just pouring some seafoam into the brake booster i notice that when it started to stall white smoke came out of the bottom of the exhaust manifold, could this be my rattling noise?? and would an exhaust manifold leak only when warm and under load??

Sounds like a header gasket leak. Mine developed a slight leak after seafoaming. It makes a slight ticking noise at idle. If yours is more of a rattle, it could be a bigger leak. As for hearing when it's only warm and under load, exhaust leaks can occur under specific conditions. If it's under load, that's exhaust being pushed out from the engine at a higher rate than at cruise. Metal also slightly expands and contracts depending on temperature, which is why you may be hearing it when it warms up.