[Gabe The Babe]

i have a 1978 W100 4X4 with a 440. i can hear a valve clacking around and its loud. its annoying too. i was wondering how bad it is to drive around with that going on. this truck isnt my everyday ride so its ok if it takes time to take care of it. i just need to know if it is going to kill the truck or what. i plan on rebuilding the motor soon enough but for know i like to drive it around on the weekends. any help i can get is welcome.

 

[lbeenken]

Depends if the vlave is stuck open or closed. If it is open and slaps the piston face you can count on catastrophic failure. If it's stuck closed it will still be hard on it but you shouldn't have to worry about massive destruction.

 

[charlie1935]

If it's stuck closed he has something bent or broken in the valve train, like pushrods or rocker arms. Could be a worn lobe on the cam. :gr_patrio

 

[moparracer]

If it is "clacking" it may have a bad lifter. This is quite common.

 

[injmopar]

load

Sometimes an oil change and an oil additive like EOS (gm product) or wynn's will fix it.My dads 69 440 300 sounded like someone was tapping on the hood.Used the engine oil suppliment and when he sold it years later it had 130,000 on the engine which ran like a top.
And a stuck lifter can cause major damage.If you bend an exhaust push rod you can hydraulic a cylinder.