94 Ranger ping/knocking

[Driller203]

My 94 Ranger knocks/pings in 5th gear when going up hills.
so bad that the check engine light comes on.
Ford dealer changed plugs, problem is still there.
Now Dealer states too much carbon on valves, common problem with
4.0L can this problem be fixed with removing the heads 7 cleaning the valves??

[Psychopete]

Originally Posted by Driller203

My 94 Ranger knocks/pings in 5th gear when going up hills.
so bad that the check engine light comes on.
Ford dealer changed plugs, problem is still there.
Now Dealer states too much carbon on valves, common problem with
4.0L can this problem be fixed with removing the heads 7 cleaning the valves??

Did the dealership pull the codes? Usually symptoms of pinging like you describe are signs of a dirty mass air flow sensor. I know of no 4.0L problem related to carboned valves and pinging, but I am not a professional by any means.

Pete