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2003 sport trac timing chain question

22william

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Cleveland oh
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03 Explorer sporttrac xlt
have a 03 sport trac xlt. Made another post that was said to be the timing chains going out. I'm getting a new engine instead of getting it fixed.
But I always asked if it was the timing chains going out. Wouldn't the noise always be loud , and always making a noise?
I'm asking because some days it starts with barely any noise. You can still hear the rattle but it's faint.
When I start driving sometimes it's kinda loud when I accelerate. And you can keep hearing it. But 15 minutes later the noise is completely gone, even when i'm in idle you can't hear it. It's quiet.So when the engine is warmed up you can't hear the rattle and it sounds like a normal truck. Why is this ?
 


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ptf18

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2002 Sport Trac
The chains that drive the camshafts (one on each head) run in "plastic" tracks called cassettes. Tensioners ( one for each chain) provide "tension' to the chains via these cassettes so the chain(s) dont "slap" around. You've probably seen this type of "slap" on a bicycle chain.

The tensioners are a spring loaded/oil pressure assisted assembly about as big around and long as adult mans thumb that are screwed into position and visible on the exterior of the engine.

When the engine is shut down only spring pressure of the tensioners are supplying pressure onto the chain (tensioning the chain). Once the engine starts oil pressure "assists" in creating additional pressure onto the chain ( additional tensioning of the chain).

As the tensioners age the springs weaken to the point that there is minimum or worse none at all tension on the chain. Thus when you start the engine you may hear a clicking type noise (I thought it was a tappet noise until I learned that these engines dont have tappets).

This clicking noise is the chain slapping the cassette and once oil pressure comes up and "pressurizes" the tensioner the tensioner applies enough tension to the chain and the clicking noise ("slap")... "goes away".

You can hear this clicking noise in other engine "power settings". I heard mine at start up.... played stupid...lost the engine.....

Someone else can pipe in if I've got this incorrect.

Its been recommended on this web-site to replace the tensioners at 75k. Yea/Nea....whatever. It cost me $5300 for a FoMoCo replacement engine... I'm going to change my tensioners at 75k on the engine....and theres some work involved from what I understand.

If your just starting to notice this "clicking noise" you might try just replacing the tensioners. Look for bits of plastic when you drain oil. That will be the cassettes breaking up. I had a bit of plastic come thru the driveside plastic valve cover. Knew I had a problem then.

Whats your engines mileage? Mine failed at 134000 which was the mileage others seem to have this problem "appear"....Poor design.....
 




22william

Member
Joined
January 4, 2017
Messages
38
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City, State
Cleveland oh
Year, Model & Trim Level
03 Explorer sporttrac xlt
The chains that drive the camshafts (one on each head) run in "plastic" tracks called cassettes. Tensioners ( one for each chain) provide "tension' to the chains via these cassettes so the chain(s) dont "slap" around. You've probably seen this type of "slap" on a bicycle chain.

The tensioners are a spring loaded/oil pressure assisted assembly about as big around and long as adult mans thumb that are screwed into position and visible on the exterior of the engine.

When the engine is shut down only spring pressure of the tensioners are supplying pressure onto the chain (tensioning the chain). Once the engine starts oil pressure "assists" in creating additional pressure onto the chain ( additional tensioning of the chain).

As the tensioners age the springs weaken to the point that there is minimum or worse none at all tension on the chain. Thus when you start the engine you may hear a clicking type noise (I thought it was a tappet noise until I learned that these engines dont have tappets).

This clicking noise is the chain slapping the cassette and once oil pressure comes up and "pressurizes" the tensioner the tensioner applies enough tension to the chain and the clicking noise ("slap")... "goes away".

You can hear this clicking noise in other engine "power settings". I heard mine at start up.... played stupid...lost the engine.....

Someone else can pipe in if I've got this incorrect.

Its been recommended on this web-site to replace the tensioners at 75k. Yea/Nea....whatever. It cost me $5300 for a FoMoCo replacement engine... I'm going to change my tensioners at 75k on the engine....and theres some work involved from what I understand.

If your just starting to notice this "clicking noise" you might try just replacing the tensioners. Look for bits of plastic when you drain oil. That will be the cassettes breaking up. I had a bit of plastic come thru the driveside plastic valve cover. Knew I had a problem then.

Whats your engines mileage? Mine failed at 134000 which was the mileage others seem to have this problem "appear"....Poor design.....
My engine is at 200k now. So it made it awhile without getting it replaced. There were bits of plastic in the oil pan. But should I still just get the tensioners replaced? Or since it's older just get everything changed
 




ptf18

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2002 Sport Trac
22william. You have some decisions to make. If your finding bits of plastic in the oil/oil pan some part of the tensioning system is/has failed.

It all depends on what you want to do with this now "old" vehicle as its going to cost you big bucks to properly repair.

You just have to sit down with a paper and pencil and write down your options. Then make a decision on the direction you want to go.

This is IMHO so take it anyway you want.

1st... the engine is bad.... at the very, very least your going to have to find out which tensioning component is bad and repair it. At the very, very least this means pulling off the front part of the engine.... IF.... its part of the system on the front of the engine.... Its PROBABLY best to remove the engine from the vehicle so you can "more" easily get access to the tensioning system. If its the rear tensioning system (which drives the passenger side camshaft) its ALOT easier to work on the tensioning components with the engine removed.

SO.... if it was me I'ld pull the engine.

2nd... if you have the engine out IMHO its silly just to "fix" the one (may be more) items that have failed in the tensioning system.. Its going to cost more (time/money) to replace the entire camshaft drive tensioning system BUT with 200k on the engine you have to wonder what would be the next piece of the system to fail?

So.... if it was me I'ld plan on replacing ALL of the camshaft(s) drive tensioning system components INCLUDING..... ALL... the tensioners (maybe a internal one)

3rd..... you have 200k miles on the engine.....its 15 - 16 years old.... unless its been operated and MAINTAINED under EXCELLENT conditions you have to wonder if there is anything else of concern WITHIN the engine that should be looked at??????
If you havent already done so, I'ld do a compression check before pulling the engine. That might help you in your decision.......
What I'm leading up to is it worth while to O/H the engine???? For me, at this point, I'm pulling the engine...and reinstalling it to repair the tensioning system so the time/money issue is a wash. With the engine out you could pull the pan and look at the con rod and main bearings for wear which will probably be found OK. With the valve cover off (to repair the tensioning system) you will see how "gunked" up the valve train is. You could pull the plugs, maybe borescope the cylinder bores for damage. Again with 200k you might want to change the oil pump and screen.

Its all about what YOU plan on doing with this vehicle... AND.... what its going to cost in time and $$$$$$.

With a bad engine your not going to recoup what you payed for it if you sell it at this point.

BUT..... you might be just throwing good money after ........bad.

If the body, interior, transmission (another "problem area") and the other "systems" are in EXCELLENT condition (given the vehicles age) it might be worth while to YOU to put 3 to 5000 dollars into a vehicle that, if you take PROPER care of should last you another.....7 to 10 years... and thats NOT screwing around with lifts, big wheels, off roading, etc.

Beats a NEW CAR payment.......

BUT.... again with 200k on NOT just the engine but the engine accessories (alternator, starter, water pump, power steering pump, hoses, serp belt pulleys/tensioner, etc) you have to consider replacing those items, How about the driveshaft U-joints?

I could go on and on but you really have to sit down and put pencil and paper together and see where it leads.

You could find a USED low mileage engine..... yeah.... and change out the tensioners before installing it.... and HOPE...... that the tensioning system is... OK.

Best of luck to you......
 




All out

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March 26, 2017
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2002 explorer sport trac
Found a piece in the oil pan a bit back and mine gave out Friday morning as I was headed to fly out of town. Mine is a 2002
 




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