Serious noise at idle.

[Rushy]

Just bought a 97 Explorer , 4.0 litre V6. has a real harsh rattle at idle and a slight sound coming off revs. Disapears on throttle up, motor performs sweetly. After reading on this site and givin the rev range of my noise, i'll be checking the timing chain and tensioner , Just a bit concerned that the noise is most obvious down around the cats, Is it possible the exhaust is amplifying the chatter off the chain threw the motor block?

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the stock 95-01 section.

 

[YBCold]

maybe the chain or an exhaust leak? i think exhaust leaks make sounds and then they close up as the pipe gets hot. i dont know what kind of engine your generation of explorer had but in the pushrod engine on the first gen the lifter click.

 

[2000StreetRod]

Cat heat shields?

Check the catalytic converter heat shields. Some members have found theirs to make a rattle type sound.

rattle coming from exhaust

Metallic rattle

 

[nelsona19]

personally i'd get rid of the 4.0 and get a 5.0l

 

[McSlug]

Take oil filler cap off and listen, I could hear my front cassette rattling.

Removing valve covers will tell you for sure if it's your front or rear cassette

 

[Rushy]

Result of pulling motor and replacing timing chains front and back was good. Noise completely dissapeared. Just for the record for those looking at this job. The rear chain is driven off an idler shaft which comes from the front of the motor. Your access for this cam gear bolt is threw a round plate on the back of the block. This also allows you to get to guide rail bolts. If you need the rear chain don't delay like i did. Pull the motor.
P.S Purchased a Haynes manual for the job. Wasn't worth the $$$. No clear cam timing illustrations. Cheers.

 

[BrooklynBay]

Thanks for the update!