4.0 engine noise

[Jim Tarr]

I'm working on a 2004 Ford Explorer 4.0 engine and it has a rattleling noise that sounds like it is under the drivers side valve cover or possibly the front cover. The motor runs well but it sounds like plastic parts bouncing all around. I know this isn't much to go on but perhaps somebody else has heard such a noise before. Any ideas will be appreciated....maybe it will help me decide where to begin. Thanks, Jim :banghead:

 

[Vic Sorlie]

How many miles on this engine? Know anything about how it's been maintained (frequency of oil changes, coolant)? A mechanic's stethoscope might be helpful to isolate the noise, and a compression check would also be helpful. If you think the noise is under a valve cover, take it or both off and have a look (have new valve cover gaskets on hand). If you see a bunch of sludge, then I'd flush the engine (AMSOIL has a product) and then start cleaning up the engine by using synthetic oil on relatively short drain intervals, say AMSOIL OE oil and a WIX filter for 2-3K miles.

 

[Dreman]

Although others will have to chime in on this to verify it, I think that may be the tensioners on the timing chain. Is it at one end or the other?

 

[H D]

It is probably the tensioners. They're a common problem with the 4.0 SOHC. There's timing chains on the front and rear. Could be either but the front one tends to go first.

 

[Max Trax]

if it is sounding like a knocking noise within the valve cover, could it be the valve lifters failing. But a rattling in the front suggest your timing chain guides broke and you'll need to replace. Next ask yourself how long you want to keep your truck, then figure out how much repair you're willing to do.

 

[H D]

Having a shop repair the timing chain guides will cost about the same as replacing with a rebuilt engine unless you do it yourself.

 

[Jim Tarr]

Your responses tell me what I thought they would. I sort of expected it would be the timing chain guides. The noise is from up front so that isn't as involved as the rear one but with high mileage on this engine it's not a good investment to repair it. The rest of the Explorer is in great condition so, perhaps an engine swap will be the way to go. I'm happy that it wasn't my trac.....it's still doing fine. Thanks everyone you are always so helpful. I'll be posting some new pics of my yellow trac soon showing the new mods that I have finished and am working on. Thanks again.....Jim :banana:

 

[FlipTrac_511]

Out of curiousity, does it rattle at all rpms?



Mine 04 rattles "only" when the engine is cold and moderate acceleration is being applied.

 

[brian brown 3]

Trac 511,

yours is probably in the early stages of wear. Mine is quiet as a mouse at 120K cold