engine noise 2.5 1999

[JustinHammonds]

I have a 1999 ford ranger 2.5L. when i start my truck up and let it sit and idle It literally sounds like my engine is knocking. Kind of like a valve knocking sound. More like it sounds like a diesel. I have changed ALL my spark plugs. New oil with lucas oil stabilizer, new sensors and everything and I dont know what else to narrow it down to. Im very close to taking it to the ford dealership to see what they can do. But does Anyone have any new ideas or findings that might help? i feel like my truck is just going to stop one of these days. it only has 128k miles which isnt much at all...

 

[Rackster]

Knocking

Just a possible guess, but could it be the water pump knocking??

 

[igotit]

try unplugging 1 plug wire at a time to rule out a specific cylinder/rod/wrist pin.
example....if the noise stops when you pull the number 3 plug wire while running....your problem is in the number 3 cylinder.
remove your oil filler cap see if the noise get louder while running,that would mean you noise is in the valvetrain,remove the valve cover inspect for wear/damage....check valve lash.
try to rule out whats not causing the noise.