Date registered: Apr 2008
Mentioned: 1 Post(s)
Quoted: 2 Post(s)
Joey, isn't the oil pressure gauge in the instrument cluster working? It should go all the way to the maximum when driving and down to around 15 PSI at idle, when the engine is warm. What does the oil look like? Is it foamy or milky looking, or is it clean, fresh and "oily" looking? A lower end (rod or main bearing) noise will be at engine speed (RPM) and sound/feel like a dull thud, almost like someone is hammering on something. It will be more pronounced under load, and a little quieter when you let off the throttle. So, on and off throttle the sound and volume will be different. A top end (valve train) noise will be at about half engine speed (RPM), higher pitched tapping type of noise. If it is a valve noise, and there are multiple cylinders involved, the noise may be continuous as opposed to intermittant when the affected cylinder valves of one or two are closed. All this being said, these engines are quite bullet proof and usually don't encounter major failures unless they have a zillion miles on them, they've been run low or out of oil, or have been grossly neglected over a long period of time. Let's check the easy stuff first....oil status (pull the dipstick to check) as indicated above, and oil pressure. If that's OK, pull the valve cover (two bolts) and take a look at the cam and valve train. Everything should be evenly wet with oil (all rocker arms and cam lobes) and nothing obviously broken or sloppy loose. The cam lobes should all me mostly shiny with maybe slight oily discoloration, and uniform...no flat, dull or worn looking lobes. You can jiggle each rocker arm. Some will be tight and some should be very slightly loose. None should be excessively loose. If everything is dry and crusty, you need to find out why. There is an oiling tube that runs the length of the engine and squirts oil onto the valve train. The oiling holes sometimes get plugged up. If it's dry you may want to have someone start the engine briefly to see if oil is coming out of these holes. Don't run it too long or you'll have a mess if it is oiling properly. If all that is OK, put the valve cover back on and loosen each spark plug wire at the spark plug. Use an insulated plug wire puller or non damaging insulated pliers and have someone start the engine. CAUTION: If you don't use insulated pliers, you'll get zapped real good. Have them accelerate the engine to the point where the noise is apparent, and then, one at a time, pull each plug wire, listen and then replace. The noise will go away or get considerably quieter when you pull the wire from the affected cylinder. Let's hope this is not the problem. Let us know how this all goes.
Last edited by mbbuff; 03-22-2010 at 09:38 PM.