My 1997 explorer sound's like a diesel engine rattling. What could be the possible cause?

[Dougy]

Has anyone heard of a 4.0 sohc oil pump screen getting plugged with sludge. Causing the engine rattling loudly all the time?

 

[drdoom]

No but I have heard of the timing chain guides breaking.

 

[swshawaii]

How to: - Timing chain rattle resolution process - SOHC V6

2000StreetRod's Helpful thread list

 

[974X4BLACKSPORT]

As stated above, the timing chain guides break. Additionally, the guides break and the pieces can fall into the bottom of the oil pan and clogging the oil pump pickup screen.

 

[C420sailor]

Could be cam chain rattle, as said above. Although that sounds more like a clatter/rattle than a knock. Worse at certain RPM (mine was worst around 2400). Those guide pieces can end up in the screen, but can’t really ‘block’ it—they’re plastic, and oil can flow around them.

Now, if something ends up in the screen that legitimately restricts oil flow (I saw someone use silicone as a gasket that half dissolved and ended up there) it can starve bearings...and a bad rod bearing can give you a very diesel-like knock.