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When should i replace spark plugs and torque specs for spark plugs?

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talontsiboy24

10+ Year Contributor
869
3
Mar 28, 2009
60457, Illinois
I replaced them 2000 miles ago should i change them again sooner then the recommended 15k mark? My car has moderate mods so i was thinkin i need to replace them before 15k? Also what are the torque specs when tightening the plugs?
 
You should probably buy a manual for your car.
If you're running the right plugs and your tune is good you don't need to change them yet.
 
I change mine when i change my oil, For a box of four i pay like 6 bucks for them. No point in waiting longer to change them.
 
really? what am i missing?? i last changed mine maybe like 10,000 miles ago so i dont see why you would need to.. maybe do it like twice a year.. and the wires like once a year.. i have warranty with autozone for life with my wires so i jus swap them..

my boy is crazy about doing is plugs like that.. one time he stripped the thread i guess he cross threaded it and he shot up a spark plug ... crazy stuff ... i dont see why.. jus check the gap.. see if they changed bad.. if not .. i leave them..

i dont remember the recommended gap for the plugs but i do that.. then install a little harder than finger tight...

so i just keep tightening with the spark plug wrench till my finger stops then fully grip it... and tighten a little.
 
i would say not to often just dont go to where they're all nasty and burnt. torque spec i have no clue, i just took mine out and put them back in. just dont go wrenching on them crazy or you'll snap them. just good and snug
 
Depends on how hard you are on the car. Or how lean or rich the tune is. Its silly to me to wait till the plugs foul to change them.

To me I would rather spend the 6 bucks and know they aren't an issue. Just like I change them before and after a trip to the track for piece of mind.
 
Use a feeler gage - the wire type can be misleading. Also, make sure the feeler isn't rusty.

As for how often to change plugs, I'd check them at every oil change - if they look good, leave them alone. Get a copy of the Haynes manual. The back cover used to have a color "how to read a spark plug" pictorial.

As for wires, I've been running a set of Magnecore's for well over a decade - sounds ridiculous, but if it aint broke don't fix it.

Hope that helps.
 
Nope, use the wire since the feeler type has errors in getting the correct gap across the entire face of the electrode.

And stay away from the ramp style since it more worse than the feeler type.

Rule of thumb on when to replace sparkplugs: new plugs: the electrode is flat with sharp edges for this gives you the fattest spark. Worn plugs: the sharp edges are rounded causing the spark flame to be reduced along with the gap being widened from recommended gap due to wear and this wider gap will give a colder, yellow spark making the system to gradually run rich and high in HC due to unburnt vapors.

Why the 15k mile changeout is due to the basic normal driving procedures. If you're a streetracer/rodded-and-modded type, it'd be a lot shorter frequency of changeout per miles.

It's just one of those things that you pull a plug to visually inspect than to wait for a certain mile range.

It's like doing your oil: do you wait until it's 3k miles, or do it when it coal black full of soot and stinks like dirty socks before changout?

-DSM
 
I've never known anyone to change out plugs even every 15k. My 3g that I track and DD has had one set of plugs since I bought (granted it's only got 12k miles on it in 3 years I've owned it), but I've never changed the plugs other than the first day I owned the car. They are still gapped fine and not fouled or anything.
 
so you wouldn't spend 6 bucks on a car you track to help it run at its optimal ignition performance?

A race team will throw away the plugs and wires after 1 race.

Even for road coursing a car I change mine after each 15 minute session as you put more continuous strain on the car in that 15 minutes than in prob a 10000 miles of daily driving it.

To me being cheap with spark plugs will usually mean cheap with other parts such as oil filters or fuel filters. I bet most people don't change theirs as part of a 60k
 
^^ I agree. Even if you drive your bone stock Dsm 1 mile round trip daily, and you check your plugs every oil change, just spend the extra 6 bucks, gap them, and put new plugs in, instead of the old ones.
 
so you wouldn't spend 6 bucks on a car you track to help it run at its optimal ignition performance?

A race team will throw away the plugs and wires after 1 race.

Even for road coursing a car I change mine after each 15 minute session as you put more continuous strain on the car in that 15 minutes than in prob a 10000 miles of daily driving it.

To me being cheap with spark plugs will usually mean cheap with other parts such as oil filters or fuel filters. I bet most people don't change theirs as part of a 60k

It's a bit more expensive in the 3g than $6, plus I see no point in changing something that is in perfect working condition. The plugs are all gapped correctly and show no signs of being fouled after all the track time it's seen.
 
if your only DD your car and not beating the piss out of it then changing them every 3k miles is overkill but for what they cost i guess i could see why it can't hurt. and with gapping them the ngk's i use come pregapped. i do my oil and fuel every 2500 to 3k miles. diesel trucks do their fuel filters every service so thats my reason for doing mine that way. i dont like skimping on the car i love
 
LOL Pre-gapped plugs? Thats a horrible sales gimmick. Always gap your plugs. It only takes a few seconds.
 
Gapping them to the same gap is important to get consistent spark across all the cylinders. Ive found pre gapped plugs to be off by about 2-4 in the same box.


It's a bit more expensive in the 3g than $6, plus I see no point in changing something that is in perfect working condition. The plugs are all gapped correctly and show no signs of being fouled after all the track time it's seen.


if you choose not to change them thats fine I think manufacturer spec is like 15 or 20k. I just think that by the time spark plug blow out or sputtering shows itself the plug has been having issues for awhile. To me the preventitive value of it is worth it.

I change my fuel filter every 10k and I clean and re oil my air filter every oil change.
 
yea there really cheap but every oil change is a lil much LOL

I kinda agree with the every oil change part! I change my oil every 6 months regardless and have changed them at the same time aswell! But in the last year all I did was check them at 6 months with the first oil change and then change the plugs on the second (1 year) oil change! I've never had a problem with anything so.....
 
Lol, you guys are silly. Basic tune up procedures guys, if you took auto in school you should know by now. Our motors have the easiest plugs to check, just look over the wires,any cracks?get new ones, Pull the plugs,which takes what, 30 seconds a piece, look over them, if they look good check the gap and put back in.

If you want to change them every time you do an oil change or a set mileage (mines 5000) Its your choice.If your anal about your cars performance, do it every time you change your oil, It really all depends on what the plugs actually look like and how hard you drive your ride.

If your not sure what bad plugs look like they are always the back page of the haynes manuals, chiltons..not sure. Good luck and hell might as well change them as a spring time tuneup.:hellyeah:
 
I haven't changed my plugs in like 10 years. Probably need to replace em, I get a li'l hiccup in idle occasionally.

I think some of you might be wasting money.

Just checking on the internet real quick, apparently they can last 60-100,000 miles. I had been just going by the sound and hadn't put any thought into the mileage.
 
I change mine when i change my oil, For a box of four i pay like 6 bucks for them. No point in waiting longer to change them.

Amen. But it sounds like your getting ripped. I am only paying 4.50 plus tax for a box of NGKs

As for wires, I've been running a set of Magnecore's for well over a decade - sounds ridiculous, but if it aint broke don't fix it.

Don't they have a lifetime warranty? I would hope they last a damn long time LOL.
 
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