Any general tips for changing sparkplugs?

Question

I'm about to change the plugs in my '98 Civic. The plugs appear very accessible and it should be an easy job, but are there any seasoned mechanics that have some general advice? I've heard to clean around the plugs with compressed air. What about anti-cease on the threads, or applying that jelly stuff (called?) where the wire connects?

Answer 1

Using compressed air to blow away debris around the base of the plug BEFORE you take it out is a real good idea. It prevents little stones, dirt and grease from accidentally getting into the cylinder where it will cause problems later on. A small dab of anti-seize on the threads will help prevent galling of the threads and allow you to get a proper torque reading on them. That 'Jelly' stuff is di-electric grease... It conducts electricity, and it prevents the contacts from corroding and allows the spark plug boots to slip on and off easier. Make sure you check the plugs for proper gap before you install them.... they aren't always right from the factory. Since it's probably an aluminum head engine, you have to be extra careful not to cross thread the plugs. I have always used a 3-4" length of vacuum or fuel hose pushed onto the end of the plug like the spark plug boot. It let's you get the plug into the spark plug hole better, and you can really feel if the plug is threading in properly. You can thread them in most of the way with the hose... and then do the final tighten with a spark plug socket or an inch-pound torque wrench. Make sure you check the torque specs to avoid over-tightening and stripping out the threads.

Answer 2

Your engine probably has an aluminum head. Remove the spark plugs with a rachet and extension if necessary, and keep the extension perpendicular to the plug. Don't angle it.

Yes, compressed air will help remove some grease and dirt from around the spark plug seat.

When the plugs are removed, inspect them for color and wear. Especially the number 1 plug can give you info about your engine. Too oily? Too hot? too black and sooty = too rich a mixture, etc.

I have never used anti-seize on the threads. Plugs shouldn't seize if everything is OK and you tighten them to the right torque. A cast iron head from the 1960's.. maybe the anti-seize woluld help.
Check the plug gap before installing new ones. I never trust them from the factory.. it's just another machine to trust.

START the new plugs back into the hole with your fingers on the rachet extension. Tighten them with fingers only until you are SURE the threads are started perfectly. THEN finish with the torque wrench or a small "inch-pound torque" wrench. You don't ever want to re-tap your cross-threaded mistakes. BAD!

If I think of more ideas, I'll return....

Answer 3

The others are correct. I'll add just one thing . . . Let the engine cool down until you can leave your hand on it for at least 15 seconds or so.

1. This will make the job a lot more comfortable.
2. You won't be as likely to strip the threads on your aluminum cylinder head. (Steel and aluminum heat and cool at different rates.)

I've used anti seize when I have some around. Can't really say it makes a difference, but it doesn't hurt, either. As long as your plug boots are in good shape and you hear that "click" when you seat the boots, I don't feel you need dielectric grease on the boots. Again, I use it if I have it . . . can't hurt anything.

You can do this, it's an easy job.

Answer 4

Two things.

1) Don't pull the "wires", pull the boots.

2) Do one at a time to keep from crossing sparkplug wires.

3) One more thing, when pushing the sparkplug wires back on, push them till you feel a light "click".

Answer 5

I think you're supposed to use a torque wrench for tightening the new plugs to avoid over-tightening. Plus what the others said.

Answer 6

on hondas make sure you put some anti-seize lubricant on the threads.