Do spark plugs need to be gaped?

Question

I 'm having difficulty with my vehicle running very rough. and 2 mechanics told me spark plugs need to be gaped. Didn't want the garage to do it because I'm looking for a new vehicle . So just wanted to do the minimum to have the car not shake so badly when I need to go somewhere. Not going far or turnpike.
so my son put in spark plugs and wires which the garage said would make it from shaking so badly and running so rough. 2 mechanics also said spark plugs should be gaped. I told my son this and he refused to do because he said he could tell me if they are gaped from looking at them. Mean time no more change in the way the car runs. So do yu think this is the reason it is running the same because the plugs weren't gaped ? Auto Zone also told me the plugs are already gaped.

Answer 1

It has been my experience that plugs are already gaped.They should be checked to be sure the gap is correct though.Are you sure the firing order on the plug wires is correct?That would definitely cause the engine to run rough if the wires aren't on the right cylinders.

Answer 2

yep the 2 mechanics is right ! plugs has to be gaped and gaped right too ! your son might have got 2 plug wires backwards ! right there will make it run rough ! never go by when the factory says already gaped ! i found out i had to gap them myself !

Answer 3

just check the gap on your plugs i gotta reset the gaps on my new plugs for my motorcycle every time if that ain't it check your plug wires and make shure that your have the right firing order

Answer 4

I think your problem is more likely wires not on right plug on 2 or more cylinders



or you may have a BAD plug, even though they're new, its still a possibility



you should check the gap when you put them in, but they are usually close enough not to make it run bad

Answer 5

New spark plugs are already gapped from the factory. Spark plugs are not your problem.



P.S. If everything ELSE is in perfect working order, your ignition will fire spark plugs with ANY gap. Modern high energy ignition systems are not as sensitive to gap distance as older breaker-point systems were.



SPARK PLUG GAP IS NOT YOUR PROBLEM



I suspect you have a bad distributor cap, possibly a bad coil, or mixed up plug wires.

Answer 6

Gap the spark plugs and use only the plugs recommended by the manufacturer.



A spark plug part number might fit hundreds of different engines from many different manufacturers. Although the factory will set the gap to a pre-selected setting, this may not be the right gap for your particular engine. The incorrect plug gap for your engine can contribute to a high rate of misfires, loss of power, plug fouling, poor fuel. (NGK website)

Answer 7

Yes or the engine will not fire correctly. Which is that shaking you feel.