Re: Champion Plugs and knocking

I recently replaced my plugs but did not opt for the truck plug. I would like to know what the difference is between the Champion RC12LYC and the truck plug. The RC12LYCs came pre-gapped .035". I don't have any knocking issues, 4.0L w/ 189600 miles.

Eric, I would grab one of the boxes the plug came in and call a different auto parts store for what model number Champion Truck plug they say is correct for your Jeep and compare that to the part number on the box in your hand. I used to run Truck plugs but I don't remember the model number or I'd give it to you. Hey, it wouldn't be the first or last time an auto parts store guy gave someone the wrong parts. Anything else changed besides the plugs?

Jerry

I'll call tomorrow. Nothing else changed, though.

I'm running Champion 4412 truck plugs in my XJ's with no problems.

Hi Peter:

Here is an explanation of all the Champion plugs:

snip

I haven't even put 50 miles on these plugs. Would the color be there already? I called a different parts store today and the part number is good to go.

Eric, how about the wiring to the plugs? Could one be not pushed onto the plug or into the distributor cap all the way?

I can double check it. But the problem isn't very persistent. It seems to only happen when the engine is under a load. I noticed today (and maybe this is out of paranoia) that there sounds like some vavle rattle when going up a hill if the engine has to work (i.e. I don't downshift). Now, I know that is normal, but I don't recall it happening before the plug change.

The only other wiring issue is the wire to the plug at the very front (can't remember cylinder number). When I pulled it out (using a wire puller), the metal sleeve stuck to the old plug. I got it off and shoved it back into the boot. I suppose that could be the problem... I don't know. I would think if that were the case, I would be idling rough and having this problem more frequently.

That's what these are -- 4412 truck plugs.