2000StreetRod
Moderator Emeritus
- Joined
- May 26, 2009
- Messages
- 10,597
- Reaction score
- 334
- City, State
- Greenville, SC
- Year, Model & Trim Level
- 00 Sport FI, 03 Ltd V8
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
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