I recently changed my oil and got a bit of rattle coming from what sounded like the timing chain and was assured by a mechanic that was normal right after the oil change. As he predicted, the sound didn't really come back.

Not long after, I noticed what sounded like the same rattling again. It sounds like it's coming from the passenger side (I assume the chain on that side) and only while the engine is cold. Once it warms up the rattling seems to go away.

My questions:

• What can I do to confirm that it's the chain rattling?
  
• What are common causes of the chain rattling (tesioner, etc.) and what can I do to narrow that down.
  
• What might be non-timing chain related causes of the rattling I hear from that area.

I ask because this appears to be an involved repair and I'll be fixing whatever it is by myself most likely and I don't want to pull all that stuff off without being sure what's wrong.

I'm also a bit ashamed to admit that I dropped a socket into the engine bay while changing spark plugs but I doubt that's the sound I'm hearing. I know the general area it's hiding and it's not anywhere scary I just won't be able to get my hands in there to get it out until I find a decent magnet to probe with.


This is a 1500 4.7L V8.

 

Jeez, what is it with "mechanics" these days? I've done a lot of oil changes and never heard a "rattle" afterwards. I'd guess if the chain is truly rattling, it's time to trade it before the engine grenades on you.

I wonder if you have a heat shield that's loose. Oh, and who hasn't dropped a socket in some d@mned unreachable place?

 

Overhead valve engines have no tensioner, it's directly connected from crank to cam. If the chain is rattling, it's stretched.

My guess would be you have a rocker arm rattling. 4.7L's are notorious from throwing a rocker. I would suspect your lifters are taking a bit more time to pump up.
I would run some Marvel Mystery oil in your oil until your next oil change. Since you just got it done and are prob full, pour just a few Oz's in and about 100miles prior to your next oil change dump 1/2qt in. It'll clean up any/all crud in your lifters as well in your oil galleries which restricts flow.
Yes, the stuff will clean up all crud even on your seals, but it will condition them at the same time. Any otherwise healthy engine will not be harmed in any way.

 

^I think there are tensioners for the primary and secondary timing chains?? IIRC the primary tensioner is spring loaded, the secondarys run off oil pressure??

 

That's what all the research done seems to indicate. I'll do some probing around this weekend and see what I find. Thanks for the replies so far

 

The 4.7 is OHC. Pretty sure there are no lifters.