need help finding a metalic rattle/grinding noise

[labeledsk8r]

yeah i kinda need some help figureing this out, and i searched around a bit and couldent find anytihng that sounded like my problem, im getting a metalic rattleing/grinding noise from the driver side of my engine bay, it only does it when i go from a lower rpm to 3,500 or more. the noise isnt a knock, i do know that,i was thinkig mayby it could be a pully? but not positive, im gona try geting a stethescope to try to pin point the problem but havent had time to just yet, the noise also only happens when its in drive, if i rev it in park or anytihng it sounds fine, any input would help alot, thanks

[88Accord-DX]

Your on the right path, get a stethescope & listen to the tranny first.. Then move it around to other points & go from there.

[labeledsk8r]

yeah i probably will tomarow or the next day depending on the weather, also if it helps to know the engine mounts are going to crap,

[labeledsk8r]

well i ended up putting medium grade gas in to see if it was samething with that (i highly doubt it) i still havent got a stethescope, but most likely will tomarow and do a quick check, any feedback would halp out alot, places to check or anything, im still noobish on this and i cant spend alot of money if i dont have 2, 17 and trying to save for college. thanks

[labeledsk8r]

i picked up the stethescope today and listened to the top half of the engine as long as i could (it kept raining off and on) im not hearing anything but i dont kow what to listen for, the rattleing noise only happens when the car is driveing and over 3500rpms , ima try to get it up on ramps tomarow and listen to the underside of it tomarow my luck it will be something in the block

[Pico]

I had the same grinding noise in mine turned out to be the a/c clutch freezing up.
I took of the a/c belt and the noise went away. It sucks now I don't have working a/c and it's hot here in the Bay Area

[labeledsk8r]

i was actully wondering if it could be that, my a/c doesnt work anyways (wich really sucks its just as bad here in florida) and i was gona try chargeing it, but if it doesnt work after the charge ima just drop it anyways, i might try just takeing the belt off just to make sure, thanks

[w261w261]

instead of a stethoscope, I use a breaker bar. Just put one end wherever you need it and the other by your ear. Works great, and you can stick it down into places that a stethoscope is hard to get to with.

[labeledsk8r]

ok, well it has rained the past few days so i didnt get the chance to take the belt of the a/c compresor, but i noticed the rattleing is less, and all i had done was use the mid grade gas, so i went and gased up again this time with premium and i have ran it now for a day and i dont even hear it except for a half a second every once in a while, compared to before its virtully gone? does anyone else have to run high grade fuel?? or is this something else? ideas please,

[kcaudill]

Could be valve rattle due to low octane fuel. My yota will not run on 87 octane without rattling. Or pinging others might call it

[w261w261]

Your timing could be off, as the car should run fine on 87. I believe, but am not sure, that if you have carbon deposits in the chamber they can be a source of preignition. There are some additives that claim to be able to take care of deposits.