2000 Explorer XLT: timing chain guide/tensioner failure

[Eighty51]

I've read horror stories about timing chain guide/tensioner failures in Explorers.

Is it true the timing chain guide/tensioner assemblies for 2000 Explorers are all faulty? I know there is a Ford kit to replace the front timing chain guide/tensioner assembly for 2000 Explorers but what about the back timing chain guide/tensioner assembly?

My Haynes Explorer service manual doesn't mention any mileage or temporal interval in which to replace the timing chains, how long do they last? When should they be replaced?

 

[Tech By Trade]

Search death rattle. A non serviceable design flaw with every 4.0l sohc produced by ford.

 

[Eighty51]

Thanks Tech By Trade, that was a depressing read.

Is the death rattle a constant rattling at start-up and idle? Or can the sound come-and-go?

I had an alarming rattle and when I got home I found the oil was low by about an 1/8 of a qt. When I topped
off there was no rattling noise on start-up or idle.

 

[2000StreetRod]

The currently available camshaft timing related components are more rugged than those that were originally installed on our 2000 models. Upon inspection at about 150K miles my rear cassette guide and my primary chain tensioner were failed. Unfortunately, one side of the rear cassette guide is still not reinforced with metal so it will eventually break. The camshaft and primary chains are strong and rarely break. If you have the balance shaft its chain is fairly flimsy but when it fails there normally is no damage to the engine.

I've owned several vehicles (Jaguars and an Alfa) with camshafts dependent on chains for their timing. Their camshaft timing was very reliable because even when the nylon/plastic chain to tensioner contact surface was worn away there was not enough slack in the chain for it to slip on the sprockets. Ford's cassette design does not prevent chain slip when the guide fails. The other flaw in Ford's design is locating the right cassette at the rear of the block/head instead of having both cassettes more accessible at the front.

If the engine is going to be entirely rebuilt for expected reliable service for many years then preventive maintenance by replacing the cassettes may be justified. Most forum members who do there own work replace their cassettes when failure symptoms occur. Many members who have to pay a mechanic replace the engine with a lower mileage engine from a salvage yard. Paying to install a rebuilt engine in a 17 year old vehicle probably is not a sound economic decision.

For more information on the timing chain system click on the "My Helpful Threads" link in my signature.

 

[david4451]

If you have rattle at startup only, it's due to lack of oil pressure in hydraulic tensioners.
If there are noises comming from timing chains at 2000 to 3000 rpm then it means some part of the plastic timing cassettes has failed.
I've fitted a pre-lube set up because I had rattle at cold start up only and never have any rattle since. Check out "pre lube and centrifugal oil filters" thread.