Rattle Unsure From Where

[irocdupi]

Ok so I have some rattles on my 03 Explorer 4.0 with 91,000 miles. Me and my mechanic have been trying to figure out what it could be, he says he doesnt think its the timing chains but i do have the 2700-2800 RPM rattle which goes away when the truck warms up. It seems to rattle more when put into gear and if you go under the truck while its running you can hear a constant click click click from the cats. Anyone have a similar situation?

 

[swetrid]

Double ck the metal shield on the left side of the transfercase, they split and rattle like a bad cat converter.

 

[rileyrs]

Well, if its coming from the cats themselves I would suspect its a heat shield.

 

[drothgeb]

I'd bet the rattle is your timing chain rattling against the timing chain guides because the hydraulic tensioners have worn out. They typically last around 75,000 miles and need to be replaced before damage occurs to the guides. Look up the write-ups by 2000streetrod, he's gone in depth about the replacement of the tensioners/guides.

This is a very common problem with the 4.0L SOHC engine

 

[drothgeb]

I wouldn't think that a heat shield would stop rattling once the engine's warm but hopefully it's that

 

[irocdupi]

Im going to have to check the heat sheilds but if it was a problem with the timing chains why would the rattle at 2800rpm under load and about 3200 in park go away after the trucks warmed up

 

[drothgeb]

The rattle on my explorer starts up around 2600 and then above 2800 it "goes away" because the engine noise mostly covers it up but it is still there. It starts at that RPM because that's when the tensioner allows enough slack that it can slap against the guides. It most likely goes away after the engine is warm because the oil is warm and getting into the small hole on the tensioners.

 

[drothgeb]

http://www.explorerforum.com/forums/showthread.php?t=287416

 

[irocdupi]

That would cause the catalytic convectors to make that click click click sound to

 

[drothgeb]

That's probably something unrelated but I'd have the mechanic check your guides. Hopefully it only needs new tensioners which are simple to replace.

 

[irocdupi]

Hopefully thats all but he says he doesnt think it is anything timing chain related he has had his stethoscope all over it while power breaking it and all.

 

[irocdupi]

Ok SO i just was under the hood, and can I be crazy but i Hear the rattle comming the loudest from the intake manifold, on the drivers side towards the frontmost part of the engine. I was cleaning out the Iac and thought let me see what I can hear so i started it up and was reeving it with my hand and it sounds the loudest when the rpms are comming down. Any suggestions when I put my ear towards the side of the block i dont really hear it as much.

 

[irocdupi]

bump

 

[rileyrs]

Ok SO i just was under the hood, and can I be crazy but i Hear the rattle comming the loudest from the intake manifold, on the drivers side towards the frontmost part of the engine. I was cleaning out the Iac and thought let me see what I can hear so i started it up and was reeving it with my hand and it sounds the loudest when the rpms are comming down. Any suggestions when I put my ear towards the side of the block i dont really hear it as much.

There is a chain and tensioner right there to drive the drivers bank cam, so if its a chain rattle i would assume that one. the primary chain and tensioner are also gonna be right below that under the timing cover, another possibility.

 

[irocdupi]

how hard is it to get to these chains, and fix them, do all of the belt drive accessories have to come off

 

[1998Explodasport]

There is one tensioner that can be replaced by just removing the thermostat housing and unscrewing it from under the front of the intake. I replaced it on my 98 and it made a world of difference noise wise. Not sure if the 03s have the same tensioner but my 01 does so I am assuming yours does too.