Timing chain issue?

[SilverPhoenix]

To add to my EATC issue (I posted a thread a couple days ago about that), earlier today when I went to the dentist my car started making a noise that has me thinking it might be time to replace the timing chain guides as I have just shy of 180k miles. However, after listening/watching several Youtube videos, the sound I hear on my car isn't like the ones in the videos I watched. To try and describe it as best as possible, it sorta sounds like an ordinary chain's links hitting sheet metal and not like the 'clack clack clack' in the videos. It's a somewhat fast clinking/rattle sound, but not as fast as in the videos I watched. It also doesn't make the sound at idle, but when initially accelerating and when slowing down just prior to reaching idle rpms the sound occurs for several seconds; same happens when in park and I give it a little gas. Last oil change was Nov last year and approx 2,000 miles ago.

Anyone here have audio of their MM with worn guides? I've heard about the dreaded timing chain guide issue, but have never actually heard what it sounds like.

[Agent2006]

You sure its not the water pump?

[SilverPhoenix]

You sure its not the water pump?

I have no clue...I'm purely speculating that it's a timing chain issue. It was 92* out when I went to the dentist to have a crown put in this afternoon when the noise started, so I wasn't in the mood to open up the hood and pretend I knew how to troubleshoot the noise...lol. I'm just getting opinions from the 'collective' as to what it could possibly be to see if there is anything I could possibly do myself before just taking it to a garage to have it looked at/worked on.

[blazen71]

Take the belt off and start it. If you still hear the noise it will rule out anything driven by the belt. If the noise goes away, spin each belt driven component by hand and see if they make any noise and/or feel rough.

[Agent2006]

Get a mechanics stethoscope from harbor freight or amazon, no fan blades in the way you can put the probe tip right on the water pump housing. I recently had to replace the belt tensioner on the MGM but it was more of a squeak, at 175,000 miles on it.

[Mr. Man]

It's been my experience that the timing chain rattle is quick and goes away once oil pressure come up to spec. It doesn't seem to come back until the car sits for a while and the oil pressure bleeds down.
Besides the above-mentioned possible problem areas, give the exhaust manifold area a look see. I get an occasional pulse on cold days that goes away when the car warms up. I'm thinking it may be a leaky header gasket.

[SilverPhoenix]

I think I figured out the problem; a rock somehow made it's way into the engine bay which got smashed into smaller pieces which clattered around making the clinking sound. Fired it up a little while ago to see if the noise would happen again and nothing...sounded just fine. Rolled back 10 feet to check for any indication of a fluid leak and discovered 3 small pieces (pea-sized) of gravel/rock/concrete, on the driveway sitting right underneath where the engine would be. Also a small line/plume of powdery like substance like you see when a rock or piece of concrete gets pulverized. Also noticed a small, single mud-dobber nest on my passenger side valve cover...lol. I need to pop the hood more often...

[azgolfrat]

When I took my MM engine, transmission, radiator, steering, and front cross member out (and everything that goes with all that) I was amazed at the number of small rocks that came out.
I felt like Fred Flintstone :-)