A rattling noise from the engine may indicate that the timing chain cassette is worn. Our technicians tell us that installing an updated cassette and timing chain tensioner should correct this concern.Google+
Car Problem Reports
Ford Ranger Worn Timing Chain Cassettes May Cause Rattling Noise From Engine
Ford Ranger Problem
Engine Affected: 4.0L V6
Average Mileage: 86,750 mi (60,000 mi - 127,000 mi)
Visitor, 2002 Ford Ranger, 4.0L V6, 127,000 mi
Rattling Timing Chain during cold start and cold engine acceleration around 2500 RPM to 3000 RPM. After the engine is warm no rattling noise can be heard. No codes, no knocking, very little valve noise. I haven't had this diagnosed by a mechanic and I'm getting it fixed soon.
Visitor, 2008 Ford Ranger, 4.0L V6, 60,000 mi
Similar problem, squealing sound , tensioner replaced belt replaced, noise got worse. Turns out it was the bottom balancer, as the two parts seperated.
Visitor, 2001 Ford Ranger, 4.0L V6, 85,000 mi
Rattling noise upon acceleration after warmup. Worse with heavier load or uphill. Thought this was a timing problem, but no OBD codes were thrown and timing advance and retard seems to be operating properly. Glad to find out this potential problem and fix.