I have 140k miles on my 2000 4.6L V8 and it has serious engine clatter at idle. Very annoying and it sounds like it's coming from the left side of the engine. Can't tell if it's lifter noise or maybe coming from the timing chain area. Sounds like it is in the front part of the engine.

Anyone know how to check this out myself without to much work. I thought it might be the belt tensioner pulley or the other belt pulley and replaced both of them but no change in the noise. I don't know where to start looking next.

 

Does the noise fluctuate with the RPMs of the engine?

 

yes it does fluctuate with the engine rpm and seems to diminish when the rpms pickup. any ideas???

 

I'd do an oil pressure test. Plumb in a mechanical oil psi gauge. see what your gettin at idle

 

Is the noise coming from the front of the cam cover or lower behind the front cover? Many times a dieseling noise is found to be from a loose timing gear retaining bolt. Easy fix just remove the cam cover and retighten the bolt. Make sure the bolt is loose by checking for tightness by hand. Jusy looking at the bolt it may look tight but may be loose enough to allow the spacer to rattle. Also while you have the cam cover off check the timing chain below the timing gear for slop. If it is real loose than you may be looking at a defective chain tensioner in which case the front cover would have to come off for a more involved repair. If both of these components look ok then check the lash adjusters for pump. If one of them is not pumped up and hard (collapsed)while on the cam lobe heal then it is defective and has to be changed. If several are not pumped than you may have a blocked oil passage or low oil pressure problem. These can all be checked while you have the cam cover off. All of these conditions can cause a "diesel" noise. There are others as well but these are by far the most common in my experience. Just a quick note; Too eliminate a pulley or FEAD component, tensioner, etc. Remove the serpentine belt and run the engine for just a short time. If the noise is gone then you are probably looking at a bad pulley, tensioner, p/s pump etc. Good luck.

 

Thanks for taking time to respond in such detail. I will take a look at these possible problems this weekend an hopefully isolate the problem and eliminate the noise without to much trouble.

 

Were you able to locate the real problem? I've got an 03 Explorer 4.6, and it's got a load-sensitive engine noise. At first, I thought maybe the catalytic converters were busted up inside, and some of the guts were rattling around inside the cat. But I could not verify the noise at the cat. By chance, I talked to an ex Ford tech, and he told me that the 4.6's have common timing chain guide problems, and the noise was probably that. He also said he's heard that noise plenty of times, and was confident that was it.

I don't want to tear down the front of the motor without hearing other people have had the same problem.

 

I suffered with the diesel noise for about three months.........tried various things including 5W-30 oil. Problem gradually worsened. Finally stranded me without any forward gears. Once the trans came out, the cracked flywheel was evident and replacement eliminated the noise. Never would have figured that a cracked flywheel could generate that sound. But, after 1000 miles without the noise, there can be no other conclusion.

 

not only is this thread over 13 years old

but a flywheel noise, is a totally different area than valve train

 

Yes, but I just ran into this past 2x using my rig so im kind of interested. Will be taking in this week. I appreciate everyones input.

 

I have a 4.6 with 100,000 that of lately kinda knocks right side very faintly on a cold start up and will go away warmed up .I can tell you I tried some LIQUI MOLY MoS2 and still hear it .

 

What brand oil filter are you using?

 

What year? Is is a 2V or 3V?

 

Sorry for the very late response but always used the Motocraft filters but changed to Wix after seeing some posts about Fords filters .Mine is a 2007 4.6 2 valve .

 

Motorcraft and Wix are okay filters. It's the Fram orange can of death you have to stay away from.