I have a 97 accord vtec with 172K miles on it. For past 4 months i've been hearing this knocking/pinging noise from the engine in the range of 1000 - 2000 rpm's. No noise below or above that range. It does not matter if i have any load on the engine. Still comes in parking. Could not figure it out why the noise is coming. Any suggestions will be great. So far i'm impressed with this car. bought it at 70K miles.

thankx in advance.