Ok I have the stupid 3.0 in my 99 truck. Tonight I drove to my friends house, and noticed some "knocking" happening int he hood, at low speeds, sorta getting up to speed, but it was mostly covered by the music. On the way home, it was much more noticeable. By the time I got home, it was a noticeable thing. I parked outside, and popped the hood, and definately heard something inside the engine!
I don't know how to say the pattern goes, but it did increase as I sped up and it was a slowish knocking sounds, not really fast.
I dunno what to do exactly, am I probably safe to drive to work? I could guess what is wrong with it, but I don't want to take the risk of me being wrong. I'm pretty sure it isn't the engine pinging by the way, its not that type of knocking...
TremorJon had the same detonation with his ' pop corn machine '. Hit a dealer and have them toss it on the diagnostic machine, check the timing.
If you feel its not detonation, purchase one of those 10$ stethiscopes from autozone and give the engine a good listening. Check the oilpan, waterpump and altenator. see if you can ' hear ' any metal-on-metal noises coming from inside.
place your ear up against a long screw driver pushed up against the engine
cheaper than buying a stethascope and you can use it to isolate engine noises
start on left side then right side of engine
first front/back then top/bottom
you should be able to determine where the noise is generated from
good luck, I hope it is nothing major
Don't panic yet. I had a Ford Elite once that sounded like I had spun a bearing. I was just driving down the road and it started this faint dull knock that got progressivly louder, deeper in tone than a ping or a lifter tick. I thought for sure it was a rod knock. Even had the thing towed. Turned out to be the water pump. Never knew a water pump would do that.
Ok from what I can tell it seems to last as the engine is cold, but "cold" is relative, since its like 40 degrees out, and didn't do it when it was colder. (40 degrees in the morning*) It is noticeable under 1500 RPMs, and when i really gun it(i like doin that!) it sortof goes away, or maybe i can't hear it? I'll try diagnosing after I change the oil and get back from work.
I dunno, my motor was pieced back together a couple times before it puked its guts out. But the final consensus on my motor was the somehow a lower rod bearing lost lubrication and the bearing failed from heat. Basically, I dumped oil out somehow or it was a freak failure..
Oh hmm, well to be honest I sortof haven't done an oil change for a while now. I lost track, but do it longer than 3k. I know its not smart, but oil is rated to 5k and my dad tells me to do that. I go along with it because I figure if something goes wrong due to old oil, its going to be his fault, so he can't at least blame me. But uhh, I had 31s on for a few months, so i dunno how far i went hehe.
BUT! It went away, at least for now! If it comes back though, I'm going to try to take a look at it. 3.0 sucks!