2003 Nissa Sentra SE-R Spec V

I have been driving the car for about 14 months. There had been no issues until a few weeks ago. One of the spark plug gaps closed. I had it replaced. It got closed again. A mechanic looked at it & said the compression was ok & he didnt think there was any debris floating around that would have closed the plug gap. THERE IS NO KNOCKING NOISE AT ALL. He put another plug in & added a washer to raise the plug up. I drove it home it ran great!. I have been told it could be the piston hitting the plug, or the timing belt caused the problem. Ive been told to replace the engine,the rod bearing, the head,run it till it dies…all kinds of things. I was told the spark plugs could be too long. I do not know what to do or how to go about getting to the route of the problem? Please help. I would hate to spend the $ putting a new engine in it…If it isn’t necessary

Are you absolutely sure these are the exact stock factory plugs?

I do not know. I have been allover the internet trying to get a straight answer on just that. I assume they are not.

Have you checked the manual? Maybe a sticker under the hood? How about the dealer?

I checked both of those but have not called the dealership. I am not sure if they would know about a 2003? It is an excellent idea!

  1. Open glove compartment
  2. Take out Owner’s Manual
  3. Refer to section listing specifications for things like spark plugs, air filter, oil viscosity, etc.
  4. Compare Nissan’s listed specs for spark plugs to what is actually installed in your car.

Bear in mind that used cars can be a veritable mine field in terms of skipped maintenance, no maintenance, or bad maintenance. Many years ago, my brother bought a '55 Chevy that seemed to lack the power that it should have had.

After many false starts, his mechanic discovered that the spark plugs were actually plugs for a fork lift engine! Yes, they fit. No, they did not work properly.

It is entirely possible that the former owner of the car installed incorrect spark plugs, but luckily the answer to the question, “Which spark plugs does my engine call for?”, can be found by simply looking in your Owner’s Manual.

The parts department should have a listing for it, it’s not that old. Good luck!

I will look I am not near my car right now. I did look previously but it can’T HURT TO LOOK AGAIN. CAPS LOCK…sorry.
If they are the wrong size why is it that this problem started after having the plugs for a year?

You might have revved the engine higher than you did before.

There is a tool on the market, called a bore-scope, that some mechanics have. With it, they can look through the spark plug hole into the cylinder. The mechanic could see if there is a foreign object, or carbon build-up, with the bore-scope. If you call enough shops, you’ll should, eventually, find one which has a bore-scope.