Hey, new here.

I don't know when it started, but I started noticing a faint knocking sound coming from 2 of the Sparkplug caps. Its on a es300 1993 by the way.

I know its coming from only 2 because when I take off that useless plastic cover and touch the 3 showing, you can feel the knocking comeing from the 2 on the righ. I don't know about the other 3 because I just dont feel like crawling on the engine to reach them (some of you may know why).

If anybody has any reasons to why the sound is happening, do tell.

I know its not a piston problem because then the whole car would be shaking just from that. I think it may be a loose connection with the sparkplug to the wire, and everytime it ignites, the electric arc makes it jump a little.

Any suggestions would be really helpful, thanks.

 

I'm not sure, but if you think it's a loose connection with the spark plug to the wire, maybe try replacing the plug wires.

 

possible valve adjustment??? hard to say as its near impossible to diagnose what sombody else is hearing...