2004 ford explorer 4.0 4x4 noise

[mmasire88]

I recently purchased a 2004 ford explorer 4x4 XLT with the 4.0L flex @ 168k miles, roughly 5 weeks ago. The truck has been cared for extremely well, it's very very clean and the interior is immaculate. I was a bit hesitant to get myself into a 4.0L with hearing about all of the timing chain issues but the motor sounded great and ran amazing. I listened to it on a cold start, and no ticks, knocks or anything, and than did the same after driving it around for about 25 minutes.

Now, about 2 weeks into owning it I decided to change the oil. It's generally the first thing I do when I get into a new vehicle is switch it over to synthetic. I went and picked up some mobile-1 high mileage 5w-30 and a Bosch distance plus oil filter. I started it up afterward, and immediately noticed a very faint tapping noise.

2 weeks later...cold starts it starts up fine, no noises, runs quiet and very smooth. I get in drive it, till it's fully warmed up and the tapping is much much louder, almost like a marbles, or popcorn. Rev it up just slightly, and I mean even 200 RPMs and the noise disappears. It will rattle very briefly if I get into heavy throttle and than disappear again. If I continue to drive it, for roughly 10 minutes after it has fully warmed up and than park it. The engine is once again quiet, no noises. The noise definitely is coming from the front of the motor. I was ready to order a brand new set of tires, but at this point I'm starting to think I should go ahead and order a timing chain set and the OTC6488 tool kit. Any thoughts? I apologize for the ridiculously long post, and much thanks in advance for any thoughts or opinions!

 

[mmasire88]

Any ideas as to why an oil change would cause my chain to start making noise? I pulled out my mechanics stethoscope and it's definitely coming from the driver's side valve cover. Much louder when I put the stethoscope on the tensioner next to the thermostat housing.

 

[Sock Puppet]

Any ideas as to why an oil change would cause my chain to start making noise? I pulled out my mechanics stethoscope and it's definitely coming from the driver's side valve cover. Much louder when I put the stethoscope on the tensioner next to the thermostat housing.

The PO could have used various oil additives, which may have changed the oil viscosity and quieted the engine down.

 

[mmasire88]

I didn't even know that was possible! I really was hoping it would last a while before I had to dig into the chains The old oil doesn't seem any thicker than the 5w-30 I just put in. It just looks like it hasn't been changed in a millennia. Sticker on the windshield shows the last time it was changed was nearly 6k~ miles ago. It sounds like it gets louder everyday I drive it. Went from a new sounding motor, to a very loud game of marbles inside my engine! Is it possible that perhaps just the hydraulic tensioner is bad? It's definitely coming from the top side of the driver's valve cover.

 

[USMCSurvivalist]

Not saying this is related but I had a ford mechanic tell me that anything heavier or additives to 5w 30 will clog the timing chain tensioners as they are hydraulic. I had both tensioners on mine changed and it cost about 500 dollars. Now before you freak out on that, its easy to do yourself, I had no Idea how easy, you just pull out the old one and torque in the new. The chain that fails on the 4.0 is actually in the rear of the engine. If you look below the manifold cover on the passengers side you will see what looks like a low profile nut, thats the tensioner. They are relatively cheap parts. As an additional note you can pull the covers off and watch it line up with the chain. At the same time you can check for any other wear below the covers and change the gaskets. I was stupid and paid a shop to do it, then they jacked the gaskets up and charged me another 420 bucks to fix those, then they jacked an injector seal doing that, and well that repair was free because I threatened to sue as my truck almost burst into flames. Since then I havent trusted anyone to do work except me.

Someone else might want to chime in, I just mentioned this because you talked about timing chains and if I am correct changing it requires dropping the engine, but I think the tensioners fail, causing it to damage the guide the tear your engine apart.

 

[USMCSurvivalist]

I didn't even know that was possible! I really was hoping it would last a while before I had to dig into the chains The old oil doesn't seem any thicker than the 5w-30 I just put in. It just looks like it hasn't been changed in a millennia. Sticker on the windshield shows the last time it was changed was nearly 6k~ miles ago. It sounds like it gets louder everyday I drive it. Went from a new sounding motor, to a very loud game of marbles inside my engine! Is it possible that perhaps just the hydraulic tensioner is bad? It's definitely coming from the top side of the driver's valve cover.

Two tensioners one at the top of the passengers side and the other in the front. Mine makes noise like yours from time to time but its not consistant. It does appear to come from the same side, if you put your ear in the wheel well can you here it too? This noise is what made me change my tensioners but it really didnt change anything. 2 years later still running.

 

[mmasire88]

Well, I've decided to go the easy route first and I ordered both hydraulic tensioners and a 27mm deep well socket last week. Should be here tomorrow, and I'll put them in. When I purchased the truck I went through and listened to the motor meticulously with my mechanics stethoscope and there just wasn't even so much as a tapping from the lifters or anything. I change the oil and as soon as I start the truck up, I hear a very very faint ticking in the driver's side valve cover, and has since gotten much louder.

 

[USMCSurvivalist]

Well, I've decided to go the easy route first and I ordered both hydraulic tensioners and a 27mm deep well socket last week. Should be here tomorrow, and I'll put them in. When I purchased the truck I went through and listened to the motor meticulously with my mechanics stethoscope and there just wasn't even so much as a tapping from the lifters or anything. I change the oil and as soon as I start the truck up, I hear a very very faint ticking in the driver's side valve cover, and has since gotten much louder.

Lifters maybe?

 

[mmasire88]

Definitely the chain making noise in there, loudest point if I poke my stethoscope around is right on top of the tensioner next to the thermostat housing. Valve train is quiet on both heads.

 

[USMCSurvivalist]

Well, I've decided to go the easy route first and I ordered both hydraulic tensioners and a 27mm deep well socket last week. Should be here tomorrow, and I'll put them in. When I purchased the truck I went through and listened to the motor meticulously with my mechanics stethoscope and there just wasn't even so much as a tapping from the lifters or anything. I change the oil and as soon as I start the truck up, I hear a very very faint ticking in the driver's side valve cover, and has since gotten much louder.

What kind of oil did you use, what kind of filter? Ive been told If your running full sythetic it could be cleaning out your system from the garbage of the previous owner. You can run it for a few hundred miles and check the oil for color.
Also found this thread
http://www.explorerforum.com/forums/showthread.php?t=250015

 

[USMCSurvivalist]

Definitely the chain making noise in there, loudest point if I poke my stethoscope around is right on top of the tensioner next to the thermostat housing. Valve train is quiet on both heads.

What about the rear timing chain? Rear pass side?

 

[mmasire88]

I used mobile 1 full synthetic with a bosch distance plus oil filter. It started out as a very faint tap the day I changed the oil, which at the time it would come and go. Now it's a loud rattle 100% of the time. I can feel it in the steering wheel, rpms jumping up and down a little bit. As far as the rear chain goes, it's nice and quiet.

 

[Tyleryac]

I use Valvoline full synthetic high millage and so far the chain only rattles at start up.

 

[mmasire88]

I use Valvoline full synthetic high millage and so far the chain only rattles at start up.

I don't think the previous owners used synthetic in this truck, dealer sticker on the window showed Castrol conventional 5w-30.

 

[USMCSurvivalist]

If your worried its dirty and its a flex fuel ex than you can run e85. A mechanic friend of mine has recently tore down some high mileage engines that run only e85 and he says they look brand new inside.

 

[mmasire88]

I don't really know whats going on with it. Went out for lunch earlier and it was rattling loud as ever. Let it sit for a little while, drove it down to the store and it sounded like a brand new engine, barely hear it running at all. I'm not familiar with this motor at all. I have a driveway full of euro cars (audis) and this is my first ford In about 10 years. All I can think of is perhaps the hydraulic tensioner is clogged/bad causing the sporadic rattle. sounds like the valve train or rear chain rattles for about 1/2 second on a cold startup but I'm assuming that's fairly normal with the hydraulic tensioners. As my audis do the same thing.