Rwing27

I have what would be a perfectly healthy and beautiful 2k2 Grand Cherokee ltd i want to sell but i have this killer metallic knock coming from the driver's side rear. right by the firewall. it almost sounds like valves hitting the piston or the sorts. is it dependent on engine RPM, indep of vehicle speed and transmission speed. I've cycled through fluids, added oil conditioner, nothing worked.... any ideas i really need to sell this... TX insurance!!

Rwing27

I forgot to add, it's the 4.7l HO V8 with an auto tranny and no aftermarket mods.

iateeple

I had a similar issue with my wife's 2003, hers is the 4.0 however. Worth a try, it turned out to be the fuel cannister purge soleniod, which on her car is located on the driver's side fender back towards the firewall. it is a small cylinder looking thing with two vacuum line and an electrical connector. In my case it sound for all the worl like a valve hitting a piston, and would increase with RPM's. no idea if this is your problem but it's free to check and like 25 bucks to replace if it is so worth a shot! Just unplug it and see if anything changes.Not even sure the 4.7 will have this but oh well. Here's a link to a picture of what it should look like.
http://www.autozone.com/autozone/cat...purge+soloniod

Rwing27

thanks man! i'll let you know. the jeep's in pa and i'm in tx so my friend's workin on it, but i'll post what happens.