2004 Explorer 4.0. Timing chain tensioners.

I read through the forums here about replacing my rear timing chain tensioner, as I have the deadly rattle others have experienced. I replaced the passenger side rear tensioner (could not believe how easy that one was)
but I still have the rattle. I would like to replace any others tensioners required but didnt see specifics for the 2004 Explorer SOHC v6 4.0 4x4.
I need to determine how many my engine may have, where they are located, and how to replace them.
Thanks for any help.
CB

2nd hydraulic tensioner

You should have another similar but longer hydraulic chain tensioner on the left head near the front on the inner side. On my 2000 the upper intake manifold must be removed. I'm not familiar enough with your intake manifold (which is different) to know if it must be removed. If your intake is like the one shown below I suspect it must be removed to access the tensioner.

Thanks 2000StreetRod
I used your walk through to replace the other tensioner.
We have had some bad weather lately so I have been able to do anything.
The rattle does seem to have quieted some from the other replacement.
Hopefully the drivers side fixes it.

Welcome to this forum! I've moved your thread into the stock 2002-2005 section.

Thanks 2000StreetRod your accurate description led me right to the part.
Thankfully the engineers got smart and the 2004 V6 Explorer SOHC doesnt require manifold removal to get to it....its right in your face!...easy access with basic tools...I am changing it now and will post the results.

Replaced the front tensioner ....still a slight rattle....but havent highway driven... I assume this means replacing the chains and guides?

Dang Dang

cbexplore said:

Replaced the front tensioner ....still a slight rattle....but havent highway driven... I assume this means replacing the chains and guides?

Click to expand...

Well thought I could get a few more miles but now the engine is losing oil pressure to the top of the motor. I had a top end flush done on it but it didnt help. Pressure gage says all is well but the extremely loud dry noise says the ports or something is clogged and not getting oil.
Looks like 5,000.00 for a new motor is the only solution now.

Pull the valve covers

cbexplore said:

Well thought I could get a few more miles but now the engine is losing oil pressure to the top of the motor. I had a top end flush done on it but it didnt help. Pressure gage says all is well but the extremely loud dry noise says the ports or something is clogged and not getting oil.
Looks like 5,000.00 for a new motor is the only solution now.

Click to expand...

If you've changed your engine oil and filter at the recommended intervals I doubt that you have an oil pressure problem. You're probably hearing timing chain rattle. If you remove the valve covers you can determine if the left and right chain guides are broken. Only a broken rear guide requires engine removal to repair.

2000StreetRod said:

If you've changed your engine oil and filter at the recommended intervals I doubt that you have an oil pressure problem. You're probably hearing timing chain rattle. If you remove the valve covers you can determine if the left and right chain guides are broken. Only a broken rear guide requires engine removal to repair.

Click to expand...

Thanks 2000StreetRod its worth checking before I blow my savings

Timing Chain Tensioner

2000StreetRod, I am a woman and I do know how to work on my truck. But this is new to me. Can you tell me where to find the timing chain tensioners, I have such a rattle and I am sure that is what it is. I have a 2004 Ford Explorer Sport Trac 4X4, V6. Can you tell me how to remove the timing chain cover? Kathie

Gene64 said:

2000StreetRod, I am a woman and I do know how to work on my truck. But this is new to me. Can you tell me where to find the timing chain tensioners, I have such a rattle and I am sure that is what it is. I have a 2004 Ford Explorer Sport Trac 4X4, V6. Can you tell me how to remove the timing chain cover? Kathie

Click to expand...

Here's a great thread that goes into detail about this rattle.

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

I'm starting to experience it now but mine seems to be coming from the front as described in the thread. I'm pretty sure it's the primary tensioner, but will be pulling the valve covers next weekend to confirm.

Unfortunately this is an issue with 6 cylinder Explorers because they use plastic...I replaced my tensioners on the rear and it didn't help.
The only way to replace everything is to pull the motor. If its the front then it can be replaced without pulling the engine.

My Helpful Threads

Gene64 said:

. . . Can you tell me where to find the timing chain tensioners, I have such a rattle and I am sure that is what it is. I have a 2004 Ford Explorer Sport Trac 4X4, V6. Can you tell me how to remove the timing chain cover? Kathie

Click to expand...

I'm not familiar with the Sport Trac but I suspect the intake manifold and valve covers are different from my 2000 Sport. However, the long block should be the same. Click on the "My Helpful Threads" link in my signature for a list of timing chain related threads.

Well my truck died on me and now has to go to the shop. Can you tell me do they have to pull the engine for the front timing chains? I don't want to get ripped off because I'm a woman, if you know what I mean and I'm sure you know that this is 75% true or even slightly higher. I was told that it had to be removed and then I read above that only if it is the back, that it has to be removed. Also, since I'm going to do this, can you tell me how to replace and easiest way to replace the fuel pump? Take off the bed or drop the tank? Oh, can you give me a quote if you can on the timing chain repair? That would help even if it is an estimated one, I have been given one and now calling 2 others to check. Thank you if you can and for your time in answering my questions.
Kathie

front cassette

The front cassette (guide assembly, chain and sprocket) can be replaced with the engine in the vehicle.

Around 2004 the head casting was changed so it is almost impossible to remove the guide assembly without damaging it unless the head is removed first. However, if the guide assembly has failed it doesn't matter if it is damaged further by removing it. Some forum members have been able to force it out with the head in place but I doubt that a professional shop would do it. If the head is not removed then the new guide assembly has to be taken apart to install it. Only the new guide assemblies can be taken apart because the pivot pin is held in place with a circlip instead of being pressed. Removing the head according to shop procedures requires the use of a special valve spring compression tool.

Timing the camshafts requires a special tool kit.

Since the replacement and timing process is labor intensive, requires special tools and knowledge it is usually expensive and many mechanics are not experienced with the process nor do they have the tools. Forum members have posted labor estimates ranging from $800 to $2,000. OEM parts are not cheap. The front cassette costs about $100. Some other parts are head gasket, valve cover gasket, timing cover gasket and crankshaft seal, balancer bolt. Aftermarket parts are less expensive but frequently inferior. A cost compromise between OEM quality and imported junk is Cloyes or Borg Warner cassettes.

I suggest that you ask each shop for a detailed parts and labor estimate. Also ask for proof that they have the required special tools and have actual experience performing the replacement. Your engine is an interference engine. Even a shop with the required tools but no experience can time the camshafts incorrectly which may result in valves being struck by the pistons on engine start after repair.


There are numerous threads on this forum about replacing the fuel pump. Some members drop the tank (what I did) and some cut a hole for access which I suspect no reputable shop would do.

Hello again. couldn't find this info for my exact vehicle. I've decided to change the hydraulic pensioners on my 2004 explorer 4.0 sohc v6 . Lot of room to get the back one off. Question on the top tensioner. Looks like an electrical plug on the thermostat is in the way. I had this housing changed a year ago cause it was leaking. Its looks like just unplugging that electrical connector won't do it. That connector goes into a fitting that looks like it has to clips that you can disingage and pull the fitting off the housing. Would this work or do I have to take the whole housing off? Thanks!

If you disengage the retaining clip the sensor can be removed. You may want to replace the sensor O ring when reinstalling the sensor.

"If you disengage the retaining clip the sensor can be removed. You may want to replace the sensor O ring when reinstalling the sensor.".

Thanks a million Streetrod. This is exactly what I needed to know!