I have a 2001 ranger. 4.0 ohc engine. 82,000 mi. the rear timing chain broke. Repair cost est. @$3000. Is this a common failure, or a fluke? I hate to spend $3000 if this thing is the modern incarnation of the Vega.
You might check with the Ford dealer on this because there was a Technical Service Bulletin issued back in August of 2004 about a timing chain rattle. I have no idea as to whether this bulletin would be applicable to your problem or not.
Normally, a timing chain may break for one of several reasons. Either there is a problem with a chain tensioner/guide or the chain is excessively worn due to lack of regular oil changes.
Just offhand, I would say a fluke but without knowing the oil change history or examination of the chain tensioners/guides it’s difficult to say for sure. Hope that helps anyway.
Rear timing chain? That implies there is also a front timing chain…These Ford Modular engines usually have only one chain…Were the valves/pistons damaged? A salvage yard engine might be a better bet than rebuilding yours…
The 4 liter OHC is not a mod motor. I would say it is a fluke given the low mileage. $3000 is pretty high, I would get a 2nd and 3rd estimate. Uusually these engines are pretty reliable.