Timing chain and tensioners

[Joe Crump]

I have a 2004 sport trac with 133K miles. My question is should I look into getting the timing chain and tensioners replaced ? And if it’s making noise, would it be upon starting up ? Or after it has warmed up ? Thanks for any advice

 

[DILLARD000]

For your V6~4.0L~SOHC Engine, assuming:
* Routine Oil+Filter changes have been done at least every 10kMiles\1Year
* Currently no "DeathRattle" from front of LeftValveCover or rear of RightValveCover
* Engine is operating normally without misfires or low power
then no need to renew TimingChains\Guides (an expensive job requiring engine pull).
Typically during engine cold starts+warmup is when rattle first becomes noticable.

However, concensus recommendation is renew the two OilPressurized TimingTensioners every 75k~100kMiles;
this is a relatively easy+inexpensive job that can be done by an owner\mechanic in a couple of hours or less.
These Tensioners tend to sludge up & fail, especially in engines that have not had routine Oil+Filter changes;
they're are a root cause of broken TimingGuides & cracked+leaking ValveCovers due to TimingChain slap.
So yes at 133kMiles the Tensioners are overdue for renewal.
Click here for more info on these OilPressurized TimingTensioners.

While your replacing the LeftFront TimingTensioner, is a good opportunity to also
replace\upgrade the notorious JunkPlastic ThermoStatHousing with an Aluminum version.
Click here for more info on the ThermoStatHousing.

 

[rwbenner]

Hey Dillard, quick question….to clarify in my head, changing the hydraulic timing chain tensioners can be done by the owner from the top of the engine and behind the right wheel well (2002 ST)….but the plastic timing chain guides can only be changed by pulling the engine for full access?

 

[DILLARD000]

Hey Dillard, quick question….to clarify in my head, changing the hydraulic timing chain tensioners can be done by the owner from the top of the engine and behind the right wheel well (2002 ST)….but the plastic timing chain guides can only be changed by pulling the engine for full access?

Yes that is correct. The RightRear Guide+Chain are the most difficult to access, no room between FireWall & Engine to get them swapped. LeftFront Guide+Chain, along with MainChain+Guides can be accessed with Engine in Vehicle. Logically everything on the Engine is easier with the Engine out of Vehicle on a stand.

 

[Brett H]

The right rear guide broke on my 2001 job one. A mechanic pulled the engine and replaced everything using a Cloyes kit. Nice and quiet now.

 

[carl beasley]

So, on this subject.... I've got 230K on my Trac. Just started hearing the Startup rattle a month ago. getting louder. Would it make more sense to replace the motor & Tranny instead of pull the motor and replace the tensioners? I've been vigilant with maintenance through the years. Not getting rid of it now...

Thanks Carl

 

[DILLARD000]

...230K on my Trac
...started hearing the Startup rattle a month ago. getting louder
...replace the motor & Tranny instead of pull the motor and replace the tensioners?
...vigilant with maintenance through the years. Not getting rid of it now

It's a judgement call;
* if you've got another vehicle to drive, then you can choose to wait until it craters
* if very dependent on this vehicle, best plan downtime+budget sooner than later
Personally I'd first try replacing the 2 OilPressurized TimingTensioners,
see if that quiets down the rattle; if not then best to plan pulling\replacing engine.
If Trans is sluggish or already has shifting issues, pulling+fixing both makes sense.
Again a judgement call; possible to get another 100k on the Trans, also possible it craters tomorrow.
Lots of variables to consider; a rebuild\replacement can have it's own problems,
very dependent on you or your mechanics skill\tools\space\time\budget.

 

[carl beasley]

I'll try the Front Tensioners replacement route first. After I replace the front end of my '07 Montero Sport 4x4. Broke the left CV axle.... Always fun around here.

 

[Todd Z]

OHH you will know when they go......