loud zzzzzzzzzzz/rrrrrrrrr noise from engine
 

I have a 94 civic ex, just passed 130000 mi and a "zzzzzzzzzzz" sound or "rrrrrrrrrrr" sound is coming from under the hood. I dont believe the timing belt has been changed (ever ) and im really concerned about it :O I havent taken a look at what the sound is yet, since its coldddddd, but this weekend it should warm up. it started about 2 weeks ago, and its getting louder. i only hear it at around 1000+ rpm, and it gets rreallllllly loud above 2000. or could this be a bad bearing? like in the alternator?

if i do have to change the timing belt, how difficult is it, and what's all involved?

It's important to localize the sound. Is it coming from the driver's side of the engine where the drive belts are located? If so, remove the power steering and A/C belts to see whether the sound goes away. If not, also remove the alternator belt and check again.

yea its on the belt side (driver's side)

The three drive belts are visible, whereas the timing belt is not because it is located inside the upper and lower timing belt covers. The timing belt probably is not producing the noise, although a bad water pump could. Nonetheless, start with stepwise removal of the three drive belts, as I mentioned above. This should help to pinpoint the problem. Post your findings to receive more feedback.

at 130,000 miles and not sure if the timing belt is changed yet, i would change it ASAP before something worse happens to your engine

ok so i took a quick look at it before and it seems like its coming from under the engine mount. so maybe its the A/C belt idler pulley? gonna remove some things sunday and see if i can make it go away.

oh and i was looking back on some of the records and the timing belt, and the whole 9 yards, were replaced in 2005, so thats a big relief.

fixed it today, it was the a/c compressor idler pulley. bearing was shot. so we cut the belt. a/c doesnt work anyway

you just gained horsepower.... its like getting a haircut for loosing weight, its not much, but every little bit helps.