Spark Plugs, Spark Plug Tubes, and Spark Plug Tube Gaskets/O-Rings

[sgtncharge]

I went online to autozone.com and saw a bunch of plugs available. Seventeen to be exact. I've always bought the least expensive plugs for vehicles I've owned. I'll probably continue to do so. I realize some may be more expensive because the gap has been preset. But I would check the gap anyway. Just to be sure. I'm not a mechanic and don't have a lot of tools such as a torque wrench. I've always just used a regular socket wrench to screw the plugs in. I also noticed none of the plugs come with a long warranty. So, I'm curious.

1. Is the the difference in price justifiable?
2. What Plug was factory installed?
3. Can I get better gas mileage using one as opposed to another?
4. Do I really need to install plugs with a torque wrench?
5. How much tolerance is there on the recommended gap?
6. How difficult of a job is it to change the plugs?
7. Will I need special tools?
8. How long should a plug be good?
9. What's your opinion on the best plug to use?

Here's a list of plugs available at AutoZone for my 1989 Toyota Van 2WD 2.2L FI 4cyl

[timsrv]

1. IMO In the long run the factory plugs are the cheapest as they are a 60k mile platinum plug. Other's may be cheaper but I'd be surprised if they make it to 60k miles.

2. Factory plugs are Toyota #90919-01115 or Denso #P16R. I usually just get the Denso plugs at www.rockauto.com as they are cheaper than Toyota (but still the same thing).

3. I know there are all sorts of gimmicks out there with claims of increased fuel mileage, but I seriously doubt there's anything that can increase your fuel mileage over that of a factory plug.

4. If you don't have a feel for how tight things should be, then a torque wrench wouldn't be a bad idea. The head is aluminum and can be damaged if you make these too tight. The plugs do have a crush washer on them and it's easy to tell (by feel) when they tighten up. Thinking back I can't remember ever using a torque wrench for tightening a spark plug .

5. I used to check gap all the time, but since they started selling plugs with that protective sleeve on them I haven't gotten one that's been off. Anymore I just eyeball them and stick them in (it's never been an issue). If you're concerned, you can get a gap gauge at any auto parts store for a couple of bucks. It's easy to check them, but probably not necessary.

6. It's easy once you get the passenger seat and the access panels removed.

7. Just a socket set that includes spark plug sockets.

8. Refer to #1. Answers will vary for A/M replacements.

9. Refer to #1 & #2

[Burntboot]

There is great little video on you tube, google spark plug factory + China and you should find it.
It will change your view on all things being created equal.
Aside from the horrible conditions that the people work in, the best parts are where they grind the electrodes by hand on a bench grinder, or the bin that the finished product get "placed" in (more like tossed).

As to miracle plugs, if there really was a way to get more HP and better economy from just a spark plug, do you not think the manufacturers would be all over it and installing them from the factory?
Bottom line is gimmicks sell and they carry a hefty profit margin.

Over the years, the single biggest cause of drivability problems I have seen, were caused by cheap plugs.
It used to be that out of a box of champions, there would be at least 1 or 2 bad ones, very frustrating.

BB

[JRSJ]

I've used NGK plugs for all the vehicles I've owned. Never had any issues with them. Though I've never tried the highend Iridium/Laser Platinum series, just the G/V-Power series.

[sgtncharge]

I think I'll look at the spark plugs annually. I cant see myself paying over $10 for 4 plugs, I usually don't buy anything made of metal if it's from China. Not saying I wont use Chinese products. I'm just not going to waste my money on them. I didn't find the video but saw the slideshow. Hard to believe the floors aren't swept. Where I work everyone has a broom.
I just looked up plugs for my van at http://www.rockauto.com and noticed all the plugs have .044 gap except Denso has .035. That's odd

[EdCrono]

Hi everyone. Have a question Spark Plug related: How do you remove the pasenger seat to have better access to all four Spark Plugs? I removed the shifters box and screws around the passenger seat, but could not reach/find the rear left bolt of this last one. I can't reach all four plugs without removing the seat. Any help is appreciated.

Thanks!

[llamavan]

Hi everyone. Have a question Spark Plug related: How do you remove the pasenger seat to have better access to all four Spark Plugs? I removed the shifters box and screws around the passenger seat, but could not reach/find the rear left bolt of this last one. I can't reach all four plugs without removing the seat. Any help is appreciated.

Thanks!

HERE is the thread on how to remove the passenger side access panel. Scroll down to post #2.

Gwen

[toad]

1
4. If you don't have a feel for how tight things should be, then a torque wrench wouldn't be a bad idea. The head is aluminum and can be damaged if you make these too tight. The plugs do have a crush washer on them and it's easy to tell (by feel) when they tighten up. Thinking back I can't remember ever using a torque wrench for tightening a spark plug .

On my old VW van, which also had an aluminum head, I went to change the spark plugs and one came out with a helicoil on it. Someone had either cranked the plug in too tight and stripped it, or put it in too loose and it rattled the threads out. Luckily the helicoil worked so I just cranked it back in!

I've been paranoid about stripping them on aluminum heads ever since. Its a good idea to first make sure they're not cross threaded going in by just using your fingers on the socket, then to hold the wrench halfway down the shaft when tightening so there's less leverage to do any damage with. It's great that the factory plugs last 60K so they don't need to be done very often.

[spacecruisers]

Pulled the wires off the plugs and all 4 were soaked pretty good in oil. I don't see anywhere on the exterior of the engine where oil could be entering. I haven't pulled the plugs entirely yet to see the firing end but what could this mean? Is there something else I should look for in order to diagnose the issue? Thanks for any help.

[djshimon]

Is there a bunch of smoke coming out the tailpipe?

[spacecruisers]

Is there a bunch of smoke coming out the tailpipe?

a little white smoke at high RPM's, but i think thats related to my coolant issues. would a blown head gasket cause this?

i pulled the plugs and all 4 were dirty and covered totally in black oil except the tip.

i would also add that my engine seems to burn oil. i have to top it off every 600 miles or so (depending on how many hill climbs i do ) no leaks anywhere or blue smoke however. i suspect a bad PCV valve but thats just a guess as i haven't taken a serious look into it yet.

anyway back to topic, i have some new plugs and wires i'd like to install but want to fix whatever issue may be causing this before i do. should i buy new spark plug tubes and tube seals?

[originalkwyjibo]

The spark plugs are mounted in a removable tube with a seal on the top. If you have oil around the plugs the seal has likely failed. When you remove the plugs the tubes may come out with them and it will all make sense. Here's a quote from timsrv:

Oil on the exterior of the plug is nothing serious. These plugs mount inside of aluminum tubes and over time the seals fail. The o-ring type seal rests against the top flange of the tube and that gets hard & cracks. All you have to do is remove the plug, pull the tube out of the head, slide-off the old o-ring, then slide on the new. Here's a link to them on www.rockauto.com:http://www.rockauto.com/en/catalog/t...tube+seal,7220

[spacecruisers]

The spark plugs are mounted in a removable tube with a seal on the top. If you have oil around the plugs the seal has likely failed. When you remove the plugs the tubes may come out with them and it will all make sense. Here's a quote from timsrv:

cool, thanks. i ordered some. The ones on there appeared to be ok...i'll update when i get them installed and see if it fixes the issue.

is there a seal on the bottom? where the tube meets the block? I noticed thats where oil seemed to collect when i pulled the tubes out.

[spacecruisers]

The spark plugs are mounted in a removable tube with a seal on the top. If you have oil around the plugs the seal has likely failed. When you remove the plugs the tubes may come out with them and it will all make sense. Here's a quote from timsrv:

just wanted to update and say thanks! pulled all the tubes out and cleaned them good. the old seals were totally hardened and cracked in pieces. ordered new ones and now my new plugs and wires are nice and dry and oil free

[Mojoworkin]

Compression test results: Cyls 2,3,4= 170psi Cyl 1 = 150 psi. Not bad overall, but a 20 psi difference?

Also - I was a little weirded out by the sparkplug situation. What is weird is that instead of the the sparkplug seating against the block, it was installed on top of the cylindrical doodad that seals agains the valve cover. Not only does it seem weird to have it between the plug's crush-washer and the motor, it looks like it has formed indentations and parts of it shear off.

I guess it's better than thinking I was looking at the aftermath of a crossthreaded plug, but this still makes me pucker. EEk!

[Burntboot]

I would be worried about that, it isn't normal, there shouldn't be metal debris.

You need to figure out where it came from, either the tube or the spark plug threads.
It could just be sloppy PO work and hopefully that strip is from the tube.
Did that plug come from the cylinder with lower compression?
While it doesn't look good, it isn't necessarily bad news.
If the threads in the head are intact, I would try chasing them (with a shop vac to suck as much debris as possible) and recheck the compression.
Threads can be heli-coiled if chasing them isn't sufficient, its a pain to do in-situ but not impossible.

You will want new o-ring seals for the tubes, they get hard and will leak oil.
Engine oil and spark plug wires don't get along well, so its important to keep them separated.

[Mojoworkin]

The shrapnel is definitely from the tube, not the engine. I'm kinda spooked by the way it's installed, and am hoping to get confirmation. Should tube be tightened between engine and plug?

[originalkwyjibo]

Should tube be tightened between engine and plug?

Yes. The tube is soft aluminum just like the crush washer on the spark plug so don't overtighten. When in doubt use a torque wrench. Spark plug torque should be 13 ft lbs. As Burntboot said, you'll probably want new o-rings for the top of the tubes.