94 ranger labor knocks at high speed

[hermtman]

I have a 94 ranger 2.3 5 speed, runs perfect, but when i get on the interstate and run 65-70 it will go to labor knocking. anyone have any ideas on how to fix this.

[DonSor]

Are you referring to "pinging" which is a symptom of fuel, compression or timing problem and which normally occurs when under load like accelerating? If you get some sort of knocking noise at steady high speed, could be "piston slap" or maybe insufficient lubrication in your rods and bearings. First make sure your oil and filter are OK.

[toddler62]

Like donsor said make sure al fluid levels are good and clean. You can also try putting in premium gas see if ping goes away. A little ping going up a hill at full throttle can happen with regular gas. might lighten up on the accelerator a little probably not great for the engine when its doing it

[hermtman]

I have ran a diagnostic test on the engine, and it says no faults found. But it also says #1 cylinder out of balance. what does this mean.

[DonSor]

One measure of a cylinder's performance is detected through a "cylinder balance test". I believe that the test involves the shorting out of cylinders and see what affect it does on the running of the engine. The test must have found out that shorting out that suspect cylinder did not affect the engine, thus, it was not performing.