Just picked up a '94 F150 4x4 4.9 with M5OD. It seems to have a "marbles" like sound coming from the oil pan area. You can hear it pretty decently at idle while cold but quiets down when warm. It only happens at idle. As soon as throttle is applied the noise goes away.

I pulled the plug wires one by one while running and it makes no difference, the sound is still there. The distributor makes some racket as well, but more of a clacking...but at the same speed as the "marbles" sound.

I thought it was a rod knock untill I started pulling plug wires. What could this be? Any info would be appeciated.

 

How does the oil pressure look? Where abouts on the oil pan is the sound coming?

 

Has great oil pressure, sounds like the drivers side towards the rear of the pan. I'm starting to think its something to do with the distributor. The truck has 198k on it.

 

I believe it to be the timing gears. I would cut a piece of hose and put one end to your ear, and the other to the areas you want to test for the noise. You'll know.

 

Weird you mention "Marbles". Strangely enough, I had a similar sound in my 300. It was Rotella 5w-40 synthetic oil. My '92, 300 didn't like that oil in 2006 or 07, can't remember the year, but it sounded just like marbles. I only ran it for a few days and drained it. Refilled with regular 10w-30 and no more marbles.

Now I don't know if the new 2013 blend of Rotella 5w-40 is different, but I'll never run that in the 300 again. Lots of members here posting that they are running it, but not sure how many are running it in their 300's.

Sorry for the marbles you may be hearing, hope its just an oil change away to regular dino oil. I would dump what's in there and use some SuperTech 10w-30 or 10w-40 and Motorcraft/Purolator oil filter, and ser if that's it. Easiest diagnosis under $30 you can get in this day and age.

 

Popped off the distributor cap and found the spring loaded button on the inside of the cap that contacts the rotor was actually laying on the top of the rotor...this was the clacking in the distributor. Put a new cap & rotor on it and at least that noise is fixed.

But still dealing with the knock/marbles noise. I did an oil change on it a few days ago and the PO must have just changed it as it came out clean. I put in some regular dino 10w30 with a Motorcraft filter and it still makes the same noises.

I climbed under the truck while running a few minutes ago and it sounds like its coming right from in between the trans & engine. I bought the truck with a totally wasted clutch so while I was replacing the clutch/slave/flywheel/pilot I snooped around and couldn't find anything that stuck out at me as being bad/messed up.

I guess its time to find a piece of hose and try again.

 

Alright...here's a video. I can actually hear it better standing by the drivers door rather than leaning over the engine with the hood open. I crawled under and filmed the area between the back of the engine and the bell housing. It seems louder on the transmission side. Noise only present at idle, with clutch in or out.

<iframe src="//www.youtube.com/embed/5HAuIQrqA8A" allowfullscreen="" width="420" frameborder="0" height="315"></iframe>

 

Wonder if it was the pilot bearing...? If the sound went away above idle/load, the pilot bearing could have been old and loose, then some damage could have happened to the transmission input shaft. This could cause the sound to persist even after a pilot bearing change by destroying it after just a few revolutions.


Big Question... How did the input shaft look where it interfaces with the pilot bearing?

My friend had this same thing happen with his M5OD behind a ford inline 4.

 

Sounds more like something is loose than what a normal rod knock would be. You also say that oil pressure is good, so that leads me further away from a major internal issue. Don't know much about manual trans, so can't say much there. Flywheel bolt slightly loose? I say this because I know that a loose torque converter nut on an automatic trans can make a tapping noise. I'm leaning towards a trans related noise from listening to that video.

Hope you have some luck with it!

 

It might be the oil pump pick up tube. They have a support bracket that bolts to a stud on one of the main bolts. I've seen more then one that had the support bracket crack and break. If that's the case the pick up tube could be hitting the oil pan.

I don't know if that's the problem but it's something to check.

 

You make a good point. That's a possibility. Even if it's not hitting the pan, the broken piece could be hitting where it broke off from.

 

The old pilot was totally dry when I replaced it. the Input shaft in the pilot area was still pretty good looking. The trans has a terrible whine in all gears but 4th, so that leads me to think that most of the bearings are trashed. When I did the clutch I drained the trans before I pulled it and gear oil came out...not cool considering the M5od requires ATF. I'll be tearing it down for a rebuild here soon.

I see what you guys are getting at as far as the pickup tube goes. Ive had a couple of 300's apart and remember that bracket in there, definatley something to keep in mind.

Thanks again for all of the ideas.

 

Just an update for anyone that may be cruising google searching. It was actually the trans. I put in a C6 automatic I had laying around and the marble noise went away. I pulled the top cover on the M5OD and all the bearings were trashed, like severely! Engine runs great and sounds totally normal. It was the tranny the whole time.

 

Glad you got it figured out!

 

good on ya mate love the 300 looking to put a 5 speed in mine soon