Sport Trac engine rattle after replacing timing chains

[johnnylisa]

Hello,
I have a 2002 Sport Trac 4.0 SOHC with 175,000 miles. I just replaced the front and rear timing chains and tensioners after hearing the rattling indicating the cassettes were worn out. It now no longer rattles when starting, but does at differing speeds and rpms when driving. I can take it on the highway for about 20 or so miles at 70 mph and the rattle will disappear temporarily after that at any speed. After sitting a while the rattle will return. It seems to me that the new front tensioner may be defective. Any thoughts or ideas regarding this would be greatly appreciated.

John H

 

[david4451]

If you have almost no milage on new timing components and timing noise is comming from front, change the hydraulic tensioner and see if that is the problem.
What was the name of the manufacturer of timing kit?
Do you have the rattle at COLD startup also?

The consensus on this forum is on OLD timing components is if you have timing chain noise at 2500 to 3000 rpm it needs new timing chains. You have new timing components and have chain noise so be very careful as you could jump time and destroy your engine!

 

[Tech By Trade]

Mine did that, spring was shot in the front tensioner. Go buy a cloyes one if you can, they have even better springs than the ford ones. If it isn't that it could be the spring on the primary tensioner, they are a pretty poor design too. Mine was the engine tech kit from rock auto.

 

[Darren ST2002]

Hello,
I have a 2002 Sport Trac 4.0 SOHC with 175,000 miles. I just replaced the front and rear timing chains and tensioners after hearing the rattling indicating the cassettes were worn out. It now no longer rattles when starting, but does at differing speeds and rpms when driving. I can take it on the highway for about 20 or so miles at 70 mph and the rattle will disappear temporarily after that at any speed. After sitting a while the rattle will return. It seems to me that the new front tensioner may be defective. Any thoughts or ideas regarding this would be greatly appreciated.

John H

John : did you end up addressing the front Tensioner, what did the part(s) / labour cost you, I think I need to do this on my 2002 it's 270,000 km on the dial... Darren

 

[Darren ST2002]

They are not Japanese quality/ built by any means, but the cost to buy is fractional also ! - Just saying !

 

[johnnylisa]

Hi, Darren - sorry I haven't updated this until now. The rattle was not from the top front tensioner, but was from the jackshaft chain tensioner - it is behind the water pump and timing cover and runs from the crankshaft to the jackshaft. The kit I purchased from a local auto parts store did not have it and I had to buy it separately from a local Ford dealer. The kit I purchased that apparently had everything but that part was about $300. I have seen them for much more and some less; I have no idea how much the quality of the components may vary. I paid a friend of a friend $800 to pull the engine and replace both timing chains, and another $150 to go back into the front of the engine and replace the jackshaft tensioner. With the benefit of hindsight, I would certainly make sure the kit I purchased had all the chains, tensioners, water pump, etc., and make sure that everything concerned was replaced at one time. Oh well, live and learn . The truck runs fine and now sounds new - no more rattles!

Several shops I originally spoke to about replacing the chains said they would not replace just the timing chain cassettes on an engine with 175,000 miles on it, but offered to install a remanufactured engine. Their concern was that if something else failed in the high mileage engine after performing the work then they might get blamed for it. The one shop that did offer to replace just the chains said it would cost about $3000 - it requires a lot of labor to pull those engines and there is no other way to replace the rear time chain cassette. The others wanted from $5500 to $6500 for installing a remanufactured engine. Ummmmm ... thank you, no, to both options - the truck simply isn't worth that kind of repair bill to me.

I was very fortunate to find a good backyard mechanic that was willing to work on it for so little as a side job.