03 expedition xlt 5.4 L

[kbat]

How many km/miles do you change your timing chain and spark plugs?

 

[99 Expy]

The 5.4s are known to have problems with spark plugs. For your year motor, I believe they have problems with blowing out plugs, but if it happens, it can be fixed. Others will chime in to correct me and tell if they've had problems. As far as the timing chain, I don't recall any big problems on having to change them out. My 99 4.6 has 170k miles on it and has the original chains in it. The chains hold up pretty good when compared to timing belts in other motors.

 

[GAINMOB]

100,000 factory recommendation for plugs...dont know bout chain

 

[toms89]

Timing chain is designed to last the life of the motor. If you rebuild motor its a good idea to change it then along with the tensioners

 

[toms89]

100,000 factory recommendation for plugs...dont know bout chain

100,000 is the factory recommended service interval for the plugs but because of the plug blowout issue many recommend changing them more frequently or at least re-torque them every so often to make sure they are not backing out. Always when cold and do not overtorque. 14 pound feet is recommended I believe.