random knock when driving

[arista5]

hey all, when i drive my car lately at random highway driving, not beating on it or up or down hill or accelerating or decelerating totally random my knock gauge dances all over.

anyone have any ideas....?

 

[blackbuick87]

Maybe a wire to your gauge or sensor is grounding out?

Just a thought but the knock doesnt occur at the same time you fan comes on does it?

 

[arista5]

cant guarantee as its highway driving and i cant tell when the fan is coming on or not.

 

[GN SBS]

I had this problem once and it ended up being a bad ground-- big ground at PS exhaust manifold bolt was totally off and knocking around.
-S.