Noisy crank pulley (harmonic pulley)

[Jason312]

Hi folks.
If got a new to me 2004 ranger XLT with the 4.0 engine. Making my way through needed maintenance and noticed noise coming from the crank pulley. Turns out there is a loose ring or something inside it that rattles around. It's not loud so I can live with the noise as long as it won't cause any other issues.

Any ideas what it is and...Will it hurt anything?

Thanks?

 

[Uncle Gump]

The 4.0L SOHC can develop timing chain rattle. If that's what's going on it isn't good.

Do some searching and read up on the issue.

They have hydraulic tensioners and guides that can go bad. If something let's go... it typically destroys the engine. Use caution and I would figure out the noise sooner then later.

 

[Jason312]

Thanks for the heads up about the timing chain.

This is definitely some sort of ring that is loose inside the harmonic pulley. I can barely see it and I can put my fingers in there and move it around. I can't get it to come out tho.

 

[Jason312]

I have found a couple posts on the Internet saying the 04-05's have a balancing ring in the pulley that comes loose. I can't find any info stating if it will cause more problems or if it's ok to leave it. I don't hear it inside the truck at all. Only when I'm outside with it idling so the slight noise doesn't bother me.

 

[tinman_72]

I have never had a 4.0 but every motor I have owned has a rubber lining inside that can rot away and cause noise before failure. If you know for a fact that it is the harmonic balancer making the noise I would plan on replacing it sooner rather than later.

 

[superj]

I say change it out too. They aren't hard to change and will keep the engine from having issues

 

[Jason312]

I really don't know if it's hurting anything. The pulley is not separating, wobbling or making any squeeking noises. Butt I better change it to be safe and to keep me from stressing over it.

 

[tinman_72]

I really don't know if it's hurting anything. The pulley is not separating, wobbling or making any squeeking noises. Butt I better change it to be safe and to keep me from stressing over it.

Or take take it off and inspect the rubber. If the rubber is not cracked, and there is no vibration then it probably is not the harmonic balancer causing the issue.

 

[sgtsandman]

I would replace the pulley.

 

[19Walt93]

If the elastomer is deteriorated the outer ring can work it's way back and grind into the crak sensor, shorting it out. I agree with everyone who said replace it.

 

[Jason312]

Update, the problem is now fixed. As stated in my original post there is a loose ring inside the pulley. It has nothing to do with the rubber damper. I have attached 2 pics of the ring loose in my old pulley and a pic of the new one with it attached properly. From my research this is an 04-05 issue only. Also, I originally replaced it with the Dorman pulley that has a presses on reluctor ring for the crank position sensor to read. This would not work for my truck. I immediately got misfire codes and it ran poorly. I tried a new crank position sensor but it still ran poorly and gave misfire codes. I returned the Dorman pulley and ordered one with the grooves (reluctor ring) machined into the pulley like the factory one and all is working great now. (Pics below of the correct pulley with machined grooves and the Dorman with the small pressed on ring that did not work)