Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
Member Login

Site Notices
Posted: 11/4/2009 3:56:57 PM EST
My truck is starting to miss out and it only has 70k miles, the Maintenance manual says to change the plugs at 100k miles.
What else could it be ?
What has been the experience of fellow members ?
Link Posted: 11/4/2009 3:57:57 PM EST
[Last Edit: 11/4/2009 3:58:32 PM EST by paul_the_welder]
on new cars that run very clean they can and will.


What kind of truck and is it at high rpm or rpm or both?
Link Posted: 11/4/2009 3:58:02 PM EST
They can last that long, or longer. I wouldn't recommend it, however.
Link Posted: 11/4/2009 3:58:22 PM EST
I drive a 2000 Chevy truck with 140,000 miles on the original AC Delco plugs and wires. Runs fine.

YMMV.
Link Posted: 11/4/2009 3:58:54 PM EST
It would depend on how much your car sits and idles. If your truck is missing just check them.
Link Posted: 11/4/2009 3:59:52 PM EST
I have yet to change the plugs in my 96 Z71, but have put a couple of dist.caps, rotors and plug wires. I have put 150,000 on it.
Link Posted: 11/4/2009 4:00:02 PM EST
There are a lot of variables, but yes they can last > 100K. I just changed them on a Ford Ranger with 110K and I just did it because I thought I should; it was still running OK.

You might want to check your plug wires and/or run some injector cleaner if you have a rhythmic miss.
Link Posted: 11/4/2009 4:00:19 PM EST
Yes
Link Posted: 11/4/2009 4:01:10 PM EST
they can last that long however sometimes after that long they may not come out in one piece so its a good idea to change them early
Link Posted: 11/4/2009 4:01:42 PM EST
The 100k platnium plugs in my wife's minivan lasted 74k miles before it started missing (hestistating on accel and idling a bit rough). They were Autolite Platnium plugs and they were worn when I replaced them.

I think the plugs are made to last a bit longer than the warranty period, which was 60k miles in my case...
Link Posted: 11/4/2009 4:03:37 PM EST
Some plugs in F150s last for the life of the engine/heads.
Link Posted: 11/4/2009 4:03:53 PM EST
If by "last" you mean plug the hole in the head and make some sort of a spark? Yes they can. If you mean "work anywhere near their optimal performance" the answer is hell no. I just bought a used car with 95K on it, and changed the plugs. The stock plugs were very good NGK platinum plugs, but still had double the specified spark gap that they should. It runs much better with new plugs in it. I'd be perfectly comfortable letting them go 50K, but IMO 100K is just too long.
Link Posted: 11/4/2009 4:03:57 PM EST
Yes. I just replaced the plugs on my wifes '01 Wrangler with 117K miles. They are supposed to be gapped at .035, they were all consistantly worn to .060-.065! Still ran fine, just thought it was time.
Link Posted: 11/4/2009 4:06:23 PM EST
Now, that's a thought. The wife's Explorer started throwing a "check engine" light yesterday at 124K, I thought we might have gotten bad gas at the co-op again. it's still on the factory plugs. Maybe I should pull a couple and look.
Link Posted: 11/4/2009 4:06:23 PM EST
Sorry my VW doesn't have this spark plug you speak of.
Link Posted: 11/4/2009 4:07:10 PM EST
[Last Edit: 11/5/2009 4:02:18 AM EST by kaos]

Originally Posted By sst04:
I have yet to change the plugs in my 96 Z71, but have put a couple of dist.caps, rotors and plug wires. I have put 150,000 on it.
'88 Ranger before my Dodge Ram.
3 sets of plugs (original and 2 more) in 315K miles. Changed the wires, rotor and cap every 75K to 100 K.

If you're running poorly, check the O2 sensor if you've got a vehicle equipped with one.

Use a good quality air filter, forget that K&N crap on the street, it's for the track if at all.

Don't forget fuel filters. In tank, in line, wherever.

ETA: I did regap the plugs a few times during the life span of the plugs.
Link Posted: 11/4/2009 4:17:04 PM EST
Originally Posted By cjk:
Some plugs in F150s last for the life of the engine/heads.


Yes, and I will sell it before I change the plugs...besides, the damned plugs are $18 a piece!
Link Posted: 11/4/2009 4:18:41 PM EST
My colorado has a slightly rough idle. Some part of the fuel injection gets covered in carbon and it makes it idle rougher. It never really hurts anything so I choose to ignore it.

I have about 130,000 miles and no reason yet to change spark plugs.
Link Posted: 11/4/2009 4:18:53 PM EST
Originally Posted By paul_the_welder:
on new cars that run very clean they can and will.


What kind of truck and is it at high rpm or rpm or both?


Ford explorer, 6 cyl. it misses at low rpm, I hear it when I am taking off and up to maybe 20 mph
Link Posted: 11/4/2009 4:20:21 PM EST

Originally Posted By cjk:
Some plugs in F150s last for the life of the engine/heads.

I think I see what you did there.
Link Posted: 11/4/2009 4:22:19 PM EST

Originally Posted By Venkman:
Sorry my VW doesn't have this spark plug you speak of.

Yeah, I got over 160k out of the glow plugs on mine.
Link Posted: 11/4/2009 4:25:45 PM EST
Link Posted: 11/4/2009 4:30:42 PM EST
Originally Posted By walttx:
Originally Posted By paul_the_welder:
on new cars that run very clean they can and will.


What kind of truck and is it at high rpm or rpm or both?


Ford explorer, 6 cyl. it misses at low rpm, I hear it when I am taking off and up to maybe 20 mph


Run a couple cans of injector cleaner through it and see if it helps.
Link Posted: 11/4/2009 4:32:51 PM EST
Originally Posted By Dilbert_556:
Originally Posted By walttx:
Originally Posted By paul_the_welder:
on new cars that run very clean they can and will.


What kind of truck and is it at high rpm or rpm or both?


Ford explorer, 6 cyl. it misses at low rpm, I hear it when I am taking off and up to maybe 20 mph


Run a couple cans of injector cleaner through it and see if it helps.


I will try that , thanks
Link Posted: 11/4/2009 4:33:32 PM EST
The extreme level of voltage that modern voltage ignition systes will keep most plugs firing long past their rated life.
Link Posted: 11/4/2009 4:38:17 PM EST
I'm thinking about changing mine out sometime soon.

Bought my 05 Tacoma with 56k on it, it currently has 73k.

Link Posted: 11/4/2009 4:42:49 PM EST
Don't buy gas at Korea Mart.
Link Posted: 11/4/2009 4:45:32 PM EST
My boss's Tacoma started missing, so they replaced the spark plugs. It still had the original ones from the factory, and had over 300k miles on it.
Link Posted: 11/4/2009 4:46:45 PM EST

Originally Posted By Chairborne:
If by "last" you mean plug the hole in the head and make some sort of a spark? Yes they can. If you mean "work anywhere near their optimal performance" the answer is hell no. I just bought a used car with 95K on it, and changed the plugs. The stock plugs were very good NGK platinum plugs, but still had double the specified spark gap that they should. It runs much better with new plugs in it. I'd be perfectly comfortable letting them go 50K, but IMO 100K is just too long.

This.
Link Posted: 11/4/2009 4:47:28 PM EST
running on 160k ones now.

AC/Delco
Link Posted: 11/4/2009 4:48:14 PM EST
2000 chevy S-10 145,000 miles on the original AC Delco platinum plugs. Just changed them 2 weeks ago.

Just because you can do it doesn't mean you should do it.

I started having trouble, so cap rotor, plugs and new wires new sepentine belt. Runs like new.
Next payday, coil, coil module.
Link Posted: 11/4/2009 4:52:39 PM EST
Originally Posted By NoStockBikes:

Originally Posted By cjk:
Some plugs in F150s last for the life of the engine/heads.

I think I see what you did there.


Not me. I know damned well what he did there.
Link Posted: 11/4/2009 4:52:46 PM EST

Originally Posted By captainpooby:

Originally Posted By Chairborne:
If by "last" you mean plug the hole in the head and make some sort of a spark? Yes they can. If you mean "work anywhere near their optimal performance" the answer is hell no. I just bought a used car with 95K on it, and changed the plugs. The stock plugs were very good NGK platinum plugs, but still had double the specified spark gap that they should. It runs much better with new plugs in it. I'd be perfectly comfortable letting them go 50K, but IMO 100K is just too long.

This.
That. 50k miles is about 750 million spark discharges. Not even tungsten would last without significant erosion.

Back in the days of leaded gasoline, plugs would last 12-15,000 miles before getting leaded up to the point they would side spark. On highway with points and coil ignition, there was minimal wear.

Now with unleaded gas, plug fouling is never the case unless the engine is trashed, then it is oil and carbon. But with electronic ignition, spark intensity at highway is much greater meaning wear is much greater which is why steel electrodes are rare and fancy metal plugs common. But the side electrode is still steel. And even tungsten will wear out.

Link Posted: 11/4/2009 4:53:18 PM EST
My grand am had 108K on the stockers and it ran fine. I put ac delco plugs back in it and it ran great.
Link Posted: 11/4/2009 4:58:42 PM EST
Plugs can and do routinely last 100,000 miles. There is no guarantee on that because a. they're considered a maintenance item, and b. conditions vary greatly. Chances are if your plugs were bad your SES/Check Engine/Emission light would be on, and if you're too cheap to visit the dealer, Autozone or similar can read the code for free to tell you the problem.

The 100,000 recommendation is routine preventive maintenance. Compare it to an oil change. Do it on the prescribed interval. If your oil gets contaiminated, change it sooner. If your plugs ARE bad, replace them sooner.
Link Posted: 11/4/2009 4:59:50 PM EST
[Last Edit: 11/4/2009 5:01:14 PM EST by AeroE]
Link Posted: 11/4/2009 7:41:07 PM EST
A set of plug is cheaper than a tow charge. What the deal with pushing the limit of the vehical preformance to prove a point. It just don't make sense to me.
Link Posted: 11/4/2009 9:05:14 PM EST

Originally Posted By Gtdhw:
Yes. I just replaced the plugs on my wifes '01 Wrangler with 117K miles. They are supposed to be gapped at .035, they were all consistantly worn to .060-.065! Still ran fine, just thought it was time.

Found the same thing with the girlfriend's Lexus. Factory Iridium tipped plugs ($12ea), replaced them at 120,000 miles. Good thing I will probably never have to do that again (kind of a PITA).

Could really tell a difference with the new ones.
Link Posted: 11/4/2009 9:10:20 PM EST
I have 99,700 miles on my TC. Still runs like a top on the original plugs. Maybe I should get around to swapping them out here soon.
Link Posted: 11/4/2009 9:27:26 PM EST
My father has a Denali with 180K on it. Hasn't touched the plugs/wires/distributor/alternator. He drives very gently and 95% of his miles are at 60-70mph cruising the highway or trips from KC to Vegas/Phoenix/MS or Chicago.
Link Posted: 11/4/2009 9:29:13 PM EST
[Last Edit: 11/4/2009 9:29:44 PM EST by Dave_A]

Originally Posted By walttx:
My truck is starting to miss out and it only has 70k miles, the Maintenance manual says to change the plugs at 100k miles.
What else could it be ?
What has been the experience of fellow members ?

Missing (same cylinder, all the time) can be:

Plugs
Wires
Coil/Coil-Pack
Valvetrain
Injector

Missing (random and floating between cyls) is a sensor problem, or an ignition module issue....

Link Posted: 11/4/2009 9:40:38 PM EST
coppers wont last you more than 30k miles without lowered output...iridium/platnums last a good bit longer....i wouldnt let ANY plug sit in 100k miles though

ive had a vehicle that had ac delco iridiums in it...they last about 90k..depending on how hard you drive the vehicle, you wires also wear out ALOT faster than plugs
remember that...
Link Posted: 11/4/2009 9:52:29 PM EST
My backup car, a 1991 Suzuki Sidekick purchased in late 1990, still has the original plugs in it and runs great. I'm terrified of the thought of trying to remove them and stripping out the aluminum threads around them. So those plugs will go to the grave with the rest of the car some day. On the other hand, I used to have a 1970 Z-28 with the high compression gas guzzler engine that needed new plugs monthly to keep running right.
Link Posted: 11/4/2009 10:17:13 PM EST

Originally Posted By Dumpster_Baby:
My backup car, a 1991 Suzuki Sidekick purchased in late 1990, still has the original plugs in it and runs great. I'm terrified of the thought of trying to remove them and stripping out the aluminum threads around them. So those plugs will go to the grave with the rest of the car some day. On the other hand, I used to have a 1970 Z-28 with the high compression gas guzzler engine that needed new plugs monthly to keep running right.

Plugs seal the threads inside the combustion chamber. The seals are taper seats, not gaskets. As such the threads should be fine. The real problem is when some jackleg over-torques the plugs, stressing them to where they can fail in shear. But you should still use anti-seize for aluminum on them. I have yet to pull spark plug threads.
Link Posted: 11/4/2009 10:21:28 PM EST
my toyota 98, 4 runner 168k and counting only tires, oil changes, wipers, brake pads and rotors and........................did i say wipers?
Link Posted: 11/4/2009 10:26:22 PM EST
Originally Posted By chadwick76:
my toyota 98, 4 runner 168k and counting only tires, oil changes, wipers, brake pads and rotors and........................did i say wipers?


NICE!

That's how it should be. My father's truck has only had the tranny replaced at 160K. it's AWD and 4WS so you'd think something there would be a problem, not so far. The tranny has a 25K warranty from the shop. He keeps track of MPG's and has gotten then same 15mpg's with the miles on it now vs the miles on it when new.
Link Posted: 11/4/2009 10:42:05 PM EST
Originally Posted By walttx:
My truck is starting to miss out and it only has 70k miles, the Maintenance manual says to change the plugs at 100k miles.
What else could it be ?
What has been the experience of fellow members ?


I'd be willing to bet that if you pulled the plugs and checked the gap you would see that the electrode has worn down and the gap is too large. I recommend changing them.
Link Posted: 11/4/2009 10:50:58 PM EST
Sure, under ideal conditions platinum/iridium spark plugs can last 100K miles. Rarely, if ever, are conditions ideal.


My 2006 WRX has iridium plugs, which IIRC are actually better than platinum as iridium is more corrosion resistant, harder, and has a higher melting point but still the manual recommends changing them at 30K miles.

I'm sure I can push it to double that, but then again I drive the car hard and don't want to compromise performance or reliability just to save ~$60 and a couple of hours to change them.

As another person said, why some people push this stuff to the limit is beyond me.
Link Posted: 11/5/2009 2:17:31 AM EST
[Last Edit: 11/5/2009 2:17:46 AM EST by gregert12]
I had to the change the 100k mile plugs at 15k since they electrodes were shot
Link Posted: 11/5/2009 2:34:55 AM EST
My plugs get changed at 10,000 miles. One of the added expenses of an engine with forced induction.
Top Top