Marbles Under the Hood?

[Joshua Mercer]

I have an odd sound under my hood while idle'ing under load. Sounds like marbles / rattling. Some say its the power steering pump, some the water pump, others the belt tensioner. I am unable to locate the sound, because it happens every once in a while. Any ideas on how to test for excessive play in pullies, or other testing methods?

 

[Nick Barber]

take a stick like a broken broom handle or something similar and place on end on each pulley at a time while the engine is running and hold the other end in you fist against your ear. you will hear which one is making the noise

 

[Rodger Tellefson]

I got that sound for awhile before my Cats went south. So, have them checked out too.

 

[Dingo]

Timing chain tensioners.

 

[Todd Z]

IF you put it in drive and hold the brake and take your foot and raise the idle to 1200 or so does it go away ???



Also is the truck tuned with an Xcal ??



I ask because I saw something weird with my truck and the Xcal tune...



Todd Z

 

[John Bartman]

I agree with Dingo the explorers have a problem with the timing chain tensioners , my son's 1997 explorer just had that problem it had the same sound as you discribe and I also thought that it was a belt tensioner but after taking it to the garage it was the timing chain tensioner and on the 1997 explorer you could look down the oil filler and see the tensioner