2000 Ranger 4.0L 4x4 engine noise HELP PLEASE!

[kpbyrom]

I have a 2000 Ranger 4.0L, milage 87,000, I have had a problem from quite some time. I have a noise coming from the bottom side of my engine. It started out as a muffled...ticking, it has now moved to a fairly loud pinging almost "diesel" noise. It only does it when below 2000 RPM. I have racked my brain as well as anyone else I could find that had any automotive knowledge. I have checked everything I know, and most people have said maybe an exhaust leak. I recently put flowmasters on and completely checked the whole exhaust system. Nothing found. I even sent it to Ford. It is throwing no codes. They sent me a letter saying that it is a characteristic noise of the 4.0L engine, but I have a hard time beleiveing that especially since the sound has gotten worse. If anyone has any ideas please let me know. I'm pullin my hair out here. thanks

 

[07rangersport]

I think ford might be right. I'm pretty sure that there were problems with the 4.0 in that year.

 

[kj ranger]

ford had a issue with the jackshaft chain and tensioner for the ohc . the noise usually was heard around 2300-2500 on accel . there was a tsb that started in 2000 with updated parts . hope this helps

 

[redneckmustang]

if it is a sohc more that likely it is the timing chain tensioners causing the noise. ford has updated tensioners to get rid of that noise. if it is a ohv it sound like spark knock. go buy some motorcraft carb cleaner from your dealer, unplug the pcv valve hose from the intake. put a 3/8 hose on the pcv valve port on the intake and the other end in the can of carb cleaner. then start the truck and let it idle until all the carb cleaner has been sucked into the engine. ford has a tsb for this problem with both engines.

 

[tito11304]

try checking the heat shield on cats. They usually rust out and start ratteling