Diesel Like Engine Noise

[GReddy Celica]

I have a 2000 GT-S and the other day I opened my hood witht the car running and I noticed a slight, diesel like noise coming from the engine. It doesn't sound like valves tapping, it just sounds like the engines natural noise but I just want to make sure this is normal, anyone else have this?

[Bling]

Does it sound like its coming from your pulleys or from the engine itself?
It's probably your belt tensioner pulley. I'm getting mine replaced this week.

[platnm]

yep tensioner pulley. had mine fixed already