acceleration rattle?

[voodoodsm]

(95 eagle talon esi)
well I have a short ram intake on my car and Ive noticed..whenever I give it a little gas on start up I hear a buzzing sound comming from the engine bay..I tried putting the old stock intake back on and I still heard it but not nearly as much...anyone else have this problem? think it may be comming from inside the engine bay or throttle body?Im just guessin here

 

[GTM]

Originally posted by voodoodsm
(95 eagle talon esi)
...
from the engine bay..I tried putting the old stock intake back on and I still heard it but not nearly as much...anyone else have this problem? think it may be comming from inside the engine bay or throttle body?Im just guessin here

In all probability the noise was there BUT ever since the job you are now hearing every noise that engine ever made... normal. It shows you are a concerned mechanic.

Chances are you tweaked some piece of sheet metal which is now going to give you fits no matter what you do. If you did everything right both times then look towards exhaust heat shields or cooling fan mounts/shields as being the source.

The intake side of an engine is quite noisy without any ducting or air cleaner, put that together with a performance engine with more than 30 degrees of valve overlap you will have noise.

You have to determine what ond how important the noise is. You can spray carb cleaner at the gaskets you disturbed or replaced to see if the engine changes at idle. You can put your foot on the gas pedal to hold 1500 rpm and tromp as hard and fast to release which should get about 3,000 rpm if all is well. If auto trans you can do a "stall" test which requires in gear on foot hard on brakes with other foot on gas pedal. Full throttle for less than 30 seconds rpm less than 2,800, then neutral for at least one min for oil to cool off. With this much torque on engine mounts heat shields WILL rattle if they ever were going to.

Let us know what you find.

Cheers,
GTM

at exha

 

[erc's_gsx]

i just posted this kind of problem, i hear a rattling noise whenever im trying to accelerate on low rpms.

 

[GTM]

Originally posted by erc's_gsx
i just posted this kind of problem, i hear a rattling noise whenever im trying to accelerate on low rpms.

Usually a rubber hammer works best when trying to jog a rattle in the exhaust system. You don't want to hit the heat shields for they will bend and perhaps end up with 2 rattles. Don't use a metal hammer for the shock won't make it happen or the noise will be so great to hide any rattle that was there.

This sort of thing is so subjective, a customer will swear it's coming from the front of the car when in fact it's in the rear. Best to have someone else drive and make it happen while you crawl all around and hang out the windows or hatch. Sometimes having a K-rail barrier will bounce the sound off the concrete. Make sure the driver is only concentrating on driving and not what you are doing. Sometime an alley in a business area will have good echos to help establish wich end or side it's coming from. You can wad up aluminum foil and shove between theat shield and exhaust to dampen any movement. It use to be these shields would pick up rocks or gravel and lodge themselves in impossible places.

Your rattle could also be from belts or accessories with loose or broken brackets which develop sympathetic harmonics only at unique speeds and loads. No one answer will provide instant relief, you or someone else will have to do the grunt work of diagnosing the problem.

Hey Doc I got this ringing in my ears... it only happens when I stand under the church bells...

Hopefully it's nothing serious and only a nusance that doesn't cause people to look, laugh and point fingers.

Cheers,
Gene