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How to: Timing chain rattle resolution process - SOHC V6

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2000StreetRod

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Year, Model & Trim Level
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There are sounds that may come from the engine compartment area that are erroneously mistaken for timing chain related issues. It is possible to isolate engine sounds from those generated by the accessories by removing the serpentive belt and running the engine briefly (one minute or less). If the noise is no longer present then it was from the accessories (belt tensioner, idler, alternator, PS pump, A/C compressor or water pump). If you still hear the noise then you know it's from the engine. The heat shield welds on the catalytic converters are prone to break with age and can rattle. This can often be detected by laying on the ground near the vehicle and listening with a length of flexible hose. Don't mistake fuel injector noise for timing chain noise. Other noise sources are the hydraulic lash adjusters, cam followers, sticking valves, knocking rod and main journals.

The dreaded SOHC V6 timing chain rattle has occurred in member's engines as early as 45,000 miles but typically not until 100,000 to 200,000 miles on the odometer. In most cases, maintaining clean engine oil and avoiding high engine revolutions at engine start will extend the life of the timing chain system. I suspect that the installation of an engine pre-oiler will significantly increase the life of the timing chain components as well as other engine components. See my helpful thread Accusump installation The left and right camshaft timing chain tensioners are spring loaded hydraulic pistons. The spring pushes the piston against the slack side of the timing chain guide assembly when there is little or no oil pressure as at engine start. The springs weaken with age increasing the chance that the timing chain might slip if there is a misfire at engine start. I suggest replacing the camshaft timing chain tensioners every 75,000 miles. For camshaft timing related part numbers see my helpful thread SOHC V6 Camshaft Timing

Ford recognized that there was a reliability problem with their original camshaft timing chain system. Improvements were made to the tensioners and the guides all of which were incorporated in the 2002 and later production vehicles. Unfortunately, the traction side of the rear guide assembly is still not metal reinforced and is prone to fracture into pieces with age. My personal assessment of original (pre 2002) component reliability from most to least ranking is as follows:
1. Sprockets
2. Chains
3. Primary guide
4. Balance shaft guide
5. Balance shaft tensioner
6. Rear guide assembly
7. Left front guide assembly
8. Primary tensioner
9. Hydraulic tensioners

Timing chain rattle is normally first detected at engine startup when the oil pressure is low. As the deterioration progresses chain rattle may become audible at the mid-range of engine speed. Sometimes the location of the rattle source can be detected by using a mechanic's stethoscope or a length of flexible hose. The only way to determine the noise source location with any certainty is to remove the valve covers and inspect. See my helpful thread SOHC V6 Timing Chain Inspection & Repair

The first step in Ford's normal chain rattle resolution process is to install the 00M12 kit. It contains a new left front chain tensioner, an oil return restrictor and upper and lower intake manifold gaskets. The cost to purchase the entire kit (PN YL2Z9E473AA) from Ford is comparable to the cost of just the tensioner (PN 7U3Z6K254B). I had about 150K miles on my Sport when I installed the kit. The installation solved my intake leaks but did little for my chain rattle. See my helpful thread Starting my 00M12 Installation

If the rattle source is at the rear you can try replacing the rear tensioner (PN 7U3Z6K254A). See my helpful thread Rear Timing Chain Tensioner Replacement

If the source of the noise is in the lower center front then it's likely that your primary (crankshaft to jackshaft) chain tensioner has failed. The original one had three leaves and the significantly improved one has six leaves and a larger mounting base. The front timing cover must be removed to replace the primary tensioner. See my helpful thread SOHC V6 Timing Chain Inspection & Repair

If the noise source is located at the upper left front then probably the guide assembly is broken. The front timing cover must be removed to replace the guide assembly. See my helpful thread SOHC V6 Timing Chain Inspection & Repair

If the noise source is located at the right rear then probably the traction side of the guide assembly is broken. See my helpful thread SOHC V6 Timing Chain Inspection & Repair. The engine (preferred) or transmission must be removed to replace the guide assembly. See my helpful threads SOHC V6 Engine Removal Procedure and SOHC V6 Rear Cassette Replacement

If you decide to replace all of the timing chain components see my helpful thread SOHC V6 Timing Chain Parts Removal Procedure for removal of the timing chain components. If you PM me your e-mail address I will send you a copy of the 2005 Mustang SOHC V6 assembly instructions.

For a list of Ford OEM timing chain related part numbers see my helpful thread SOHC V6 Timing Chain Related PNs
 



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another good informative post by 2000. sums it up pretty good :thumbsup:.

i might try to change my rear tensioner soon since that is where i hear my rattle(sounds like it at least) between 2800-3200'ish rpm. with 205k miles on the X, anything is worth trying before i have to rip the engine out. luckily i have none @ start-up thus far(knocks on wood).
 






Great information. Thanks for taking the time to type out your thoughts.
 






thanks i hope this works
 






So if I ONLY notice my "rattle" at lower rpm's (the lower the rpm's the more noticeable it is) and it smooth's out upon throttle, what particular area should that insinuate? To me it sounds as if the sound's coming mostly from the rear of the engine. I notice it more sitting in the vehicle than standing in front of it. But like i said, Under RPM, you can't hear a single tick.
 






The higher the rpm, the more the chains stay wrapped around the sprocket thus tightening somewhat. Slower speeds allow for more slack so youll hear it more.

If you hear it more in the rear of the engine, it is most likely the right side tensioners worn or broken.

BTW: I bought my explorer for $200 and wound up with $2500 after fixing several things and putting new tires on it. I saw the woman I got it from today at a red light and she was glaring at me...probably thinking, "you're driving my car that you stole for 200 bux....." oh well lady. Learn to mechanic.
 






Just as a note for anyone who is going to attack the chains and tensioners, i would highly suggest removal of engine before attempting this. I replaced primary, left and rear guides, tensioners and most sprockets and chains, however it is extremely awkward with the space given by just removing the transmission and top/front of engine. It helped greatly to have had a 3" body lift beforehand.
 






morning guys. im from mozambique and got a 1999 explorer. my mechanic changed the front timing chains but the car wont start. could you help me with some tips on how to proceed. cheers
 






timing chain replaced but car wont start

morning guys. im from mozambique and got a 1999 explorer. my mechanic changed the front timing chains but the car wont star:(t. could you help me with some tips on how to proceed. cheers
 












Need help

This is very good, thank you!!!

So I must ask. I have a rattle also (01 Sport 4.0 SOHV). I start it up and the RPM are always a bit higher then and it runs perfect. Give it a min or 2 to warm up, I hear a tick and the RPM drop to normal idle. Then I hear the damn rattle. I have already changed external items with no success. It is so hard to catch what area it comes from but if I take the Oil Fill cap off I really hear it louder then.

I only hear it then, low idle and I saw the answer above about higher RPM causing chain to be tighter. So I have a few questions.

Does this seem like a tensioner issue then since it only happens at low idle?
If so can this be done without removing engine? (I did see a post about removing cover and accessing by the top.)
What is that single tick when the idle adjusts?

thank you so very much for your help. (btw, she has 170,000 miles)

EDIT:: I still hear it as stated above.. but. It is a TON louder under the truck. So maybe I should check some heat shield or cat.
 






I'm not sure about the tick but the rattle comes from the chain riding over some bolts from the plastic chain guides being worn out or broken.
 






This is very good, thank you!!!

So I must ask. I have a rattle also (01 Sport 4.0 SOHV). I start it up and the RPM are always a bit higher then and it runs perfect. Give it a min or 2 to warm up, I hear a tick and the RPM drop to normal idle. Then I hear the damn rattle. I have already changed external items with no success. It is so hard to catch what area it comes from but if I take the Oil Fill cap off I really hear it louder then.

I only hear it then, low idle and I saw the answer above about higher RPM causing chain to be tighter. So I have a few questions.

Does this seem like a tensioner issue then since it only happens at low idle?
If so can this be done without removing engine? (I did see a post about removing cover and accessing by the top.)
What is that single tick when the idle adjusts?

thank you so very much for your help. (btw, she has 170,000 miles)

EDIT:: I still hear it as stated above.. but. It is a TON louder under the truck. So maybe I should check some heat shield or cat.

You can do the primary tensioner/guide and front cam tensioner/guide/chain without taking the engine out, only the radiator. I would suggest just doing this. The procedure is fairly easy removing all the parts from the front of the engine. If it's really loud your guide is probably broken.

EDIT: Though if you do this and fine out the oil pump tensioner is broken or it's actually the REAR chain, you will have to take the engine out or fight with the transmission.
 






I have an 01 sport trac with audible chain noise at start up and also a very quite chain noise while driving at 2000-2800 rpm but when ever I try and locate it with the hood open I can never replicate the noise. Any tips on trying to narrow my search?
 






I diagnosed that one of my timing chains had broken when my 1998 Explorer Sport died on the road. I pulled the engine and replaced all 3 chains, tensioners, etc. Upon putting the engine back in, I followed all instructions on how to ensure all pistons were in correct position in order to time correctly. Now when i start the motor, it will turn over right away and idle with a tapping noise that I automatically assumed was valves due to being out of time. Not enough power to drive down the road but enough to drive around the yard. VERY FRUSTRATED, NEED SUGGESTIONS!!!!
 






compression test?

If you were driving the vehicle and a chain actually broke then there was a good chance of valve damage. I suggest that you perform a compression test on all cylinders. For an engine in good condition the compression should be 180 psi with the throttle held wide open.
 






This answered my next question, the rattling. Ours has been doing it for quite a while now. Thanks for the helpful info......
 






I have an 01 sport trac with audible chain noise at start up and also a very quite chain noise while driving at 2000-2800 rpm but when ever I try and locate it with the hood open I can never replicate the noise. Any tips on trying to narrow my search?

Have used a stethoscope in the past to locate noises.....
 






I have an 02 XLT. Fairly loud rattle at startup (worse on very cold mornings). Once it idles for a couple minutes, the noise goes away and she's quiet. I figured it was the tensioner, but I replaced both and noise is still there. I still have the noise with the serpentine belt removed.

Now, I just figured that if it was something damaged (guides?) that the noise would still be there after warming up. Am I wrong? By the way, it definatelu sounds like it is coming from the rear of the motor.
 



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cold start rattle

I have an 02 XLT. Fairly loud rattle at startup (worse on very cold mornings). Once it idles for a couple minutes, the noise goes away and she's quiet. I figured it was the tensioner, but I replaced both and noise is still there. I still have the noise with the serpentine belt removed.

Now, I just figured that if it was something damaged (guides?) that the noise would still be there after warming up. Am I wrong? By the way, it definatelu sounds like it is coming from the rear of the motor.

The cold start rattle may be more due to a lack of oil than cold. My cold start rattle was due to a broken rear guide assembly. Even aften replacing all of the failed camshaft timing components the engine still rattled at cold start for a second or two. I eliminated all cold start rattle by installing a pre-oiler. The only way to know with certainty the source of your problem is to visually inspect.
 






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