So I have a 2006 4.0l ranger it's a xlt 4×4. And I have a rattle going on that I believe to be timing chain related and I'm just looking for some conformation before I go pulling the engine. So what happens is the truck starts fine 90% of the time once in,a while,it starts and makes a weird grind noise but that's very seldom. Truck idles fine I can very very faintly hear my rattle when the trucks idling placed in park. However as soon as I put it in gear and hit the gas I hear my rattle. It doesn't matter how warmed up the truck it's always there whenever I'm pressing the gas and as soon as I let off it goes away. I'm a little confused since I only have 60,000 miles on the truck. The noise also just started when I changed the spark plugs before that it ran great.it sounds like it's coming from the rear passenger side timing chain when I'm in the truck. I have motorcraft plugs in double platinum with the right heat range and gapped perfect. I did have to re thread one of the holes is it possible that could have caused a problem? If not what do you think is causing this I'm stumped and about to pull the,motor. Thanks guys

 

How did you re-thread it, and is that the plug nearest the rattle sound?

 

I just ran a thread tap through it the threads were slightly damaged. I coated the tap in oil to help catch the shavings. I ran it in part way and brought it back out cleaned it and did it again till it was all done. And then blew air in the hole to remove any left over shavings. That plug is on the side that's rattling but is cylinder #1 I think. It's the front passenger plug that I did and the sound seems to be coming from the rear chain cover from what I can tell. I've checked it and that plug is tight in there it's not lose and rattling around when idiling.

 

Coincidences are rare so there probably is some connection, but it may just be that you are paying more attention to it after working on it. Make sure the plug did not get tapped at an angle and is no longer sealing. Otherwise I'll back out and let someone familiar with the 4.0 answer. Good luck.

 

I never thought about it not dealing perfect i'll check that out. I wondered if it could be a bad egr valve or maybe a knock sensor, but like you said it's just weird it just started it definitely wasn't there before though. But I appreciate you feedback thank you!