Chilkoot

Over the past few days a slight constant rattle has developed at idle under the hood. I can't tell where's it coming from, and with any throttle it gets drowned out by my (loud, needs to replaced) alternator.

Is it likely it's a heat shield or something simple, or are these cars not generally prone to any specific rattles? I think it developed after a run from 0-45 that took her up to ~5k rpms, could this likely cause anything specific?

I'm really hoping it's not detonation, the sparkplugs/wires/caps/rotors are all about 1.5 years and maybe ~7k miles old. I do have terrible city mileage, maybe 12-15mpg with a light foot but am still getting ~22mpg on the highway as of two weeks ago on a 300mile round trip. Could it be that my bad engine temp sensor has been running the car so rich that it fouled my plugs that quickly?

Thanks for any and all help,
Adam

ecuwil

Any suggestions on the above, I recently had my alternator replaced and developed a similar noise that was not here before the alternator went out.

Thanks for any feedback,
Wil

Lavrishevo

iTrader: (1)

Are you using premium fuel? Do you know how to listen for pinging. One of the best ways is when the engine is hot and under load like going up a hill. Is the car actually hesitating or driving any different? Or is it just a new noise? You need to narrow it down.

ecuwil

Sorry for being vague and I think I have found the issue. The rattle is only there when the car is at idle and with the AC on. When I turn the AC off it stops. The AC works fine which leads me to believe that it is the compressor clutch. It is just odd that it started right after replacing the alternator.