Spark Plugs Replacement?

[DKVL]

Hello All,


My 2002 Mustang GT has 29,000 miles. It has never had it's spark plugs replaced. Should I get it replaced now?

Concerns after searching on information about spark plugs.:

1. Blown plugs. Is this an issue that I should be concern about if I plan on having my mechanics do it?

2. Since my plugs have never been touched, would replacing it now risk damaging the threads (ie: threads becoming one with the plug over long periods of time)?

3. Also, has there been a fix for it (permanent fix)?

4. Which spark plugs should I use? Should I stick with OEM? How much are they per piece?

~Thanks everyone.

 

[GDawg]

I run a different plug since I'm blown (NGK TR-6) but IMHO you can never replace your plugs too often. I've fouled my plugs with water and each time I replace my plugs the car runs so much better. It's a pain in the ass to replace them but it's a good feeling to do so. Just be sure to use "anti-seize" on them.

 

[trinity_gt]

Definitely use anti-seize on new plugs in aluminum heads.

After replacing plugs, I usually go back after a tankful of gas and, with the engine cold, verify the plugs are all tight. I might then wait a month before re-checking them a final time. Too many stories of plugs backing out to not be careful here.

As for your plugs...29,000 miles? I doubt there's any benefit to swapping them out now. They're probably not showing any wear at all. If you like, you can take them out and inspect them and gap them if need be but I strongly doubt they'll need replacing. If you do take them out, see above regarding anti-seize and re-checking.

Do NOT overtighten and do NOT do plug work work on anything other than a stone-cold engine.

 

[SVT32VDOHC]

I'd say wait till 100,000. I have 111,900 miles on my 97 F150 with a 5.4L and they are original and the truck runs great. I'm not touching them.

They do blow out...there are old threads...many of them about blown plugs. Seems like it's happened to everyone. If it happens, just buy a Heli Coil kit from the AP store. I bought one off the help rack for a car one time for 11.99. I put it in, and drove it home. Car made track runs, dyno pulls, street racing etc....never came back out.

 

[DKVL]

Yeah, I was searching old threads about blown plugs and the two consensus is that people over tighten and ruin the threads and another is they leave the plugs in for too long and that caused the thread to be stripped as you remove the plugs. Either of which makes me real nervous to think about.


Also, are there any upgrades for the heads and cams on the 2002 GT's? Or are we pretty much stuck with the crap design that Ford made? I mean I would love to upgrade the heads and cams if I can and start saving for one. Any thoughts and ideas?

If head and cam upgrades are available, which do you guys recommend and do they fix the problem for blown plugs?

 

[trinity_gt]

Also, are there any upgrades for the heads and cams on the 2002 GT's? Or are we pretty much stuck with the crap design that Ford made? I mean I would love to upgrade the heads and cams if I can and start saving for one. Any thoughts and ideas?

The PI heads aren't that bad. The SVO heads flow better but require a different intake manifold. There are a number of outfits around that do ported versions of PI heads and they can be made to flow quite well. For a daily driver though, big port CFM numbers shouldn't be the only deciding factor. Bigger is not always better for daily-drivers: Reduced port cross section and higher velocity means better low-end torque, even if it means giving up a bit up top. On a DD, what percentage of time do you spend below 4000RPM and what percentage above?

Comp XE262AH cams are a good "stage 1" upgrade that can net 20-30HP near redline with no loss down low. Add some decent long-tube headers, a high-flow midpipe and you're well on your way.

Or you could save you money toward a twinscrew or centrifugal supercharger and leave the rest stock...

 

[Zoie_daGT]

I dont think it would hurt to change the plugs but, I dont see a HUGE benefit now. Make sure you change them properly and tq them properly too. I run NGK TR6s too but, I have a few mods. If you plan on leaving it stockish, the stockers will be fine IMHO.

There are cams avail. for our cars. I am going Comp Cams or custom when I have the cash. Cushman, Crane, and others makes cams for the 2vs. Normally, you can only port and polish your heads. However, next year there will be new heads avail. From what I hear(threads are on here too), they should do good. I guess we will all see from there.

 

[DKVL]

Ok, i am a bit confused. This might be a stupid misunderstanding. The piece the spark plugs plugs into is the head right?

If so, there is no replacement for this piece?

Also, arent all mustang GT 4.6 engines? Why can't we use the newer GT's parts if we ever blown a plug? I am assuming Ford has made the necessary changes since these spark plug ports have been known to blow.

Also for the new Head and Cams, who will be making the new heads (which brand)? When will they be available?

 

[Slow35th]

The PI heads aren't that bad. The SVO heads flow better but require a different intake manifold. There are a number of outfits around that do ported versions of PI heads and they can be made to flow quite well. For a daily driver though, big port CFM numbers shouldn't be the only deciding factor. Bigger is not always better for daily-drivers: Reduced port cross section and higher velocity means better low-end torque, even if it means giving up a bit up top. On a DD, what percentage of time do you spend below 4000RPM and what percentage above?

Comp XE262AH cams are a good "stage 1" upgrade that can net 20-30HP near redline with no loss down low. Add some decent long-tube headers, a high-flow midpipe and you're well on your way.

Or you could save you money toward a twinscrew or centrifugal supercharger and leave the rest stock...

my car with said cams made 5 rwhp more than stock. and lost big torque down low

 

[DKVL]

I am currently looking into the new Trick Flow Heads made by modular depot. I was wondering, for those who have heads and cams switched out, how does that affect your ability to pass smog test?

I live in California, would these bolt on modifications create a problem for passing the smog test? Or the bolt on has nothing to do with passing the smog test?

 

[the98stang]

I am currently looking into the new Trick Flow Heads made by modular depot. I was wondering, for those who have heads and cams switched out, how does that affect your ability to pass smog test?

I live in California, would these bolt on modifications create a problem for passing the smog test? Or the bolt on has nothing to do with passing the smog test?

Yes, they will create big problems as far as passing smog in CA. You would most likely pass with a stage 1 cam, but anything more than that and your screwed. CA smog laws are retarded.....

 

[DKVL]

This is true even if i have stock pipes? There is no virutally no other mods on my gt.

Anyway to have the trick flow and still pass the smog check?

 

[trinity_gt]

my car with said cams made 5 rwhp more than stock. and lost big torque down low

Really? Were they installed correctly? Degreed?

Mine made close to 30HP by redline and didn't lose anywhere. My results were not far from what MM&FF found:

Comp Cams XE262AH Ford Mustang Two-Valve Test - Muscle Mustangs & Fast Fords Magazine

Yeah yeah, I know...magazine. But my results were similar to theirs.

 

[the98stang]

This is true even if i have stock pipes? There is no virutally no other mods on my gt.

Anyway to have the trick flow and still pass the smog check?

You would pass if you had stage 1 cams and Trick Flow heads. But the tune would have to be dead on and you would need the stock mid pipe/exhaust manifolds. Either that you find a guy that will illegally pass you for some extra $$ .... you didn't hear that from me

 

[DKVL]

I was under the impression that heads would not play a major factor in passing smog check. Instead, I was told that cams is more to blame if passing smog check becomes an issue.

The Trick Flow 2V Heads I am thinking about purchasing can operate with stock cam. I am assuming with stock cam, trick flow 2V head and stock everything else would not be a problem for me when it comes time to pass the california smog check.

Someone please tell me if I am misunderstanding something here? I know a lot of you guys have a mustang that is heavily modified with bolt on's or superchargers. Will my future set up be a problem when it comes to passing smog check?

 

[trinity_gt]

I was under the impression that heads would not play a major factor in passing smog check. Instead, I was told that cams is more to blame if passing smog check becomes an issue.

The Trick Flow 2V Heads I am thinking about purchasing can operate with stock cam. I am assuming with stock cam, trick flow 2V head and stock everything else would not be a problem for me when it comes time to pass the california smog check.

Someone please tell me if I am misunderstanding something here? I know a lot of you guys have a mustang that is heavily modified with bolt on's or superchargers. Will my future set up be a problem when it comes to passing smog check?

My car, before the blower, had stock heads, Comp 262AH cams and an MRT catted H pipe. It failed smog miserably (like 100 times the limit on one of the tests...) I took the MRT pipe off and slapped on the factory H-pipe with its 2-cats-per-side and the car sailed through the test easily, far below the limits. I don't think heads will make a huge difference though those that affect swirl and charge motion greatly might see increases. Still the OE cats should easily deal with that.

For the KB blower (at least), it's got a bypass valve that allows it to run "boost-less". I can rig it in a valet mode to prevent boost and thus the car operates just as it would normally aspirated, except it's got 36# injectors and a tune. I forsee no emissions issues with this either.

 

[DKVL]

Thank you all once again.

I am planning on getting the trick flow heads when it is available. Hopefully, it will be a great bolt on.

 

[DKVL]

Also, reading about spark plugs being blown out of the heads is a bit scary. I was wondering, if my spark plugs have never been touched or replaced since 2002, I should not mess with them at this point right? I am guessing if it hasnt blown yet, it will not any time soon right? Hopefully.

What are you guy's opinions?

 

[DKVL]

Anyone?

I am guessing that majority of the spark plugs being blown out of the heads occurred after people changed them out incorrectly. Although there are cases where the the same blow out happen on GT;s coming directly from factory, it is happening at a minimum.

Should i just leave my spark plugs alone until I hit 100k?

 

[the98stang]

I should not mess with them at this point right?

Correct. Those plugs are designed to last 100k miles. Don't mess with them.