Ok, I'm freaking myself out...

[DeanMoriarty]

I accidentally came across a thread this morning about the problems with the 4.0 sohc timing chain tensioners... I'm worried that what I thought was an exhaust noise may be the timing chain. Even if it's not, I'm worried I may have to drop a bunch of $$$ to replace it anyway, since it seems like a part that should have been recalled. Anyone have any experience with this and can tell me what exactly I should be listening for? Is the sound steady, or erratic? The sound mine is making almost sounds like popcorn popping in a tin, very erratic. Not too loud. I'm pretty sure it's coming from the exhaust, but having the rear timing chain I'm not so sure I can isolate it just to the exhaust. It "seems" to be the same as the noise it makes when I shut the engine off, that I associate with the exhaust cooling, but I'm not positive. At 135k, should I replace the front timing parts soon, regardless? It's an 01 sport. Thanks in advance.

 

[Earl43P]

Relax.

http://www.explorerforum.com/forums/showthread.php?t=163298

 

[DeanMoriarty]

Ahhh... I'd like to relax.
Problem is, I came across that same thread as I was waiting for a response... Took it out and drove it and it's exhibiting exactly the rattle at 2500-3000 rpm as the TSB specifies. Crap.
Now I have to decide if I want to fix it now or let it go for awhile and see if it gets worse (probably a bad idea).

 

[DeanMoriarty]

Anyone else?
I've read about people throwing some seafoam in there and using synthetic oil to quiet down the noise. It's not loud now, at all really... but I don't know if I'm safe letting it go for awhile before I get it fixed.

 

[Earl43P]

I only know of one local example. She drove her Explorer for over two years (it was out of warranty) with the rattle. She finally found a local tech/mech who pulled her engine and did the cassettes upgrade for $600. It took a LONG time and a LOT of miles for hers to get really noisy.

I picked up a 99 4.0 Explorer with the SOHC, high miles. I listened all over that engine (even underneath and behind) at all kinds of rpms and never heard anything suspicious. Intake vaccum leak drowned out everything, even the PS pump. I suspect it got the cassette fix by a previous owner.

It'll obviously get louder as it gets worse. You have to make the call, but if you can hardly hear it now, I would hardly worry about it.

 

[DeanMoriarty]

Lol... That's what I like to hear.

Mine is far out of warranty, with 136k on it.
$600 sounds like a steal. I can't find anyone who will touch it for under $1500.
For that price, I think I may just drive it until it blows or gets a lot louder... and have another engine put in. One of the mechanics I called actually suggested I do just that.

 

[RangerKid25]

if your going to drive it untill it blows you might as well try z-max that might help and its a hell of alot cheaper than $600 lol