2006 Ranger 3.0 with 97,000 miles.

A brief history: When I bought the truck 2 years ago it was misfiring and throwing codes. I had the recessed valve issue, so I replaced the cylinder head and the misfires and misfire codes have never returned. However, the engine has never had what I would call a smooth idle. I would describe it as a warble, and I can visibly see the engine shake a little. At about 1500 to 2500 rpms, it starts to sound like marbles in a can. Shortly after replacing the head, I had one of the main catalytic converters replaced (the misfires did their work), followed by the radiator. I believe that was the last major component replaced. I drive the truck every day to work with no problems. Still, I wish I knew what this sound is and if I can fix my pesky rough idle. There are no codes.

Here is a video I recorded of the sound: https://youtu.be/E8XFKoRHRJ8?si=b-g37bvxJLIPWVVA

Any ideas what it coule be? I have also tried Seafoam with no change in the sound or idle.

 

Is the sound quality bad?

 

Man in having trouble hearing the marble sound. I think the only time I heard something somewhat unusual on the vid was around the tail end of the video.

Do you think it’s something internal to the engine or something rattling around in the engine bay?

Have you modulated the throttle from within the engine bay itself before to see if the higher RPMs cause the engine to warble more thus warbling upon loose items that might cause a marble sound? :)

Best,
RT

 

Lol, I will try to record a new video and post this weekend. I've been chasing this sound since I bought the truck. I already replaced one of the exhaust manifolds with a hairline crack over a year ago. No change.

It sounds like something mechanical, almost like those spring door stops used for an interior door, but with a more metallic click. The sound corresponds with the engine RPM and vehicle speed even when I am coasting to a stop, with my foot off the gas pedal. Click click click click.... almost like a loose timing chain, but I hear that's not an issue with the 3.0 engines. Not sure if it's related to the engine warble, lol.

 

Okay, take two.

The sound can be heard clearly in this recording, which I took from under the truck thinking it might be the catalytic converter, but there's nothing loose inside when hit with rubber mallet. I'm starting to think it might be a lifter. The sound can't be heard from the engine bay when idling, but you can hear it at 1,500 RPM or so.