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Wrong spark plugs!

My car started missing. Had the computer read and it stated failure in cylinder #3 and ignition coils. Replaced spark plugs, boots, and ignition coils. Started and it ran worse than before. Figured out that they gave me the wrong spark plugs; took them back and got the right ones. Replaced them and it runs really crappie but not as bad as before. It really sounds like it’s jumped timing; I don’t have this confirmed because I can’t drive it and haven’t been able to get anyone to come read the computer again and check it out. My question is… Can the wrong spark plugs cause it to jump timing… and if not what else should I be looking at? It’s a 2.4ltr and they gave me the spark plugs for the v6… don’t know if it makes a difference. Also it was started 1 time with the wrong plugs and blew 3 plugs back out; 2,3,&4

If you replaced 3 plugs and 3 of them blew out when you started the engine, this job is clearly beyond you. Either you didn’t put the plugs in correctly or someone severely damaged the threads in the head.

Either get help from someone who is experienced working on cars or tow it to a shop.


I looked up the plugs on Rockauto. It looks like the 4 cylinder plug is longer than the V6 plug. The V6 plug wouldn’t run as well but it should not cause damage. In any event, it wouldn’t cause the car to jump timing.

If it actually blew 3 plugs out, that is your problem. The threads on those cylinders are likely damaged and the engine won’t run right until inserts are installed to fix the threads. Agree with @oldtimer_11, this seems beyond your skills.

If it blew the plugs out, you more than likely damaged the coil pack.

I’d like to know the plugs blew out. All vehicles I’ve owned that have coil packs - the coil packs are screwed to the head - keeping them in place. If the plug blew out any of these vehicles…the coil pack would be destroyed…it would be very obvious.

You have to get this towed to a shop that can repair the threads for those plugs.

A “Heli coil, or Time serts” weill have to be installed in those plug holes.
This is a tricky job that should not be attempted by a novice.