On my way to work yesterday, the engine in my '99 Corolla started misfiring. It wasn't bad, but it was bad enough that I could feel the engine's roughness and a lack of power. This morning I thumbed through my owner's manual where in the back I write down all the maintenance I've done to the car. I noticed the last time I changed the spark plugs was back in '07 at 122K miles. The odo now has 241K, so I thought that would be the most logical place to start my troubleshooting. I run the NGK plugs that have two side grounds that the center electrode sparks to. One plug was completely black (I'm assuming that's the one that was misfiring), while the other 3 seemed to have the normal hazy look. All 4 plugs had worn down the center electrode to the point to where it wasn't even round anymore (looking at it from the end of the plug), it was shaped more like a flat tipped screwdriver. Not only that, but the gap between the center electrode and the side grounds was huge. I'm surprised the engine was running as good as it was right up until it started misfiring. In retrospect, I shouldn't have gone this long on these plugs. I should probably change them every 75K-100K. I'm sure the engine wasn't running as efficiently as it should be once the the electrodes started wearing down and it was probably hurting my fuel economy somewhat. Still, I'm impressed that these plugs went this long, considering they're not platinum plugs or any other type that's meant to last 100K or more. NGK plugs continue to impress me and I will continue to use them.
120K on a set of regular plugs
- Thread starter grampi
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I have the original plugs in my 2000 Intrepid. Just passed 139,000 miles. I cleaned them around 120,000 and put them back with a little anti-seize on the threads. Champion Plats.
My Ford plugs are supposed to be 100k plugs but I changed out the ones on the Escape at 60k and 130k. My 06 Mustang GT has the dreaded 2 piece plug that often breaks when changed. Its at 51k and I will replace at 60k. I friend of mine did his Mustang at 83k and they still looked good. NGK plugs have a good reputation. I used them when I owned a Nissan. If they made a replacement plug for my Mustang I would consider them. Champion makes a 1 piece plug for it but I have seen mixed reviews on them.
Originally Posted By: Kuato
I'm curious - about both vehicles - what is the recommended interval on your plugs?
I think it was 100,000 miles.
I'm curious - about both vehicles - what is the recommended interval on your plugs?
I think it was 100,000 miles.
Platinum plugs are great because they can go 100K miles. Although fails can happen after 100K. The plug tips can break off causing an increased resistance on the coil which will eventually lead to coil failure. Spark plugs are cheaper than the coils that fire them so don't go over 100K unless you like buying new coils to match your new plugs.
I pulled my iridiums at 105k, and they looked ready to go another 100k. Not that I would do or suggest that.
My fear with those high mileage plugs is seizing in the head and stripping it during removal.
NGK - thumbs up!
BTW- grammpi, shouldn't you be in Grand Cayman about now?
My fear with those high mileage plugs is seizing in the head and stripping it during removal.
NGK - thumbs up!
BTW- grammpi, shouldn't you be in Grand Cayman about now?
Originally Posted By: Old Mustang Guy
My Ford plugs are supposed to be 100k plugs but I changed out the ones on the Escape at 60k and 130k. My 06 Mustang GT has the dreaded 2 piece plug that often breaks when changed. Its at 51k and I will replace at 60k. I friend of mine did his Mustang at 83k and they still looked good. NGK plugs have a good reputation. I used them when I owned a Nissan. If they made a replacement plug for my Mustang I would consider them. Champion makes a 1 piece plug for it but I have seen mixed reviews on them.
Not sure about the nature of the mixed reviews on the champions, but to eliminate the risk of broken plugs in your cylinder head and best possible case helicoiling, worst case head removal, I'd put up with changing them more often to go with the 1 piece plug.
My Ford plugs are supposed to be 100k plugs but I changed out the ones on the Escape at 60k and 130k. My 06 Mustang GT has the dreaded 2 piece plug that often breaks when changed. Its at 51k and I will replace at 60k. I friend of mine did his Mustang at 83k and they still looked good. NGK plugs have a good reputation. I used them when I owned a Nissan. If they made a replacement plug for my Mustang I would consider them. Champion makes a 1 piece plug for it but I have seen mixed reviews on them.
Not sure about the nature of the mixed reviews on the champions, but to eliminate the risk of broken plugs in your cylinder head and best possible case helicoiling, worst case head removal, I'd put up with changing them more often to go with the 1 piece plug.
Originally Posted By: ChiTDI
I pulled my iridiums at 105k, and they looked ready to go another 100k. Not that I would do or suggest that.
My fear with those high mileage plugs is seizing in the head and stripping it during removal.
NGK - thumbs up!
BTW- grammpi, shouldn't you be in Grand Cayman about now?
I'm not even sure what a Grand Caymen is. I'm really liking the the Nissan Cube though. My daughter just bought a new one. I don't care for the exterior looks much, but the amount of interior space in that thing is nothing short of amazing! Talk about getting the most from a given platform size, Nissan has done just that with the Cube. I also love the CVT tranny. But I'm getting off topic here.
Someone asked earlier what the recommended plug change interval was. For the Corolla it's every 30K. Also, someone mentioned the worry of getting the plugs out after they've been in for so long. I always use anti-sieze on the threads, especially since the Corolla's heads are aluminum, and I've yet to have a problem removing the plugs regardless of how long they've been in.
I pulled my iridiums at 105k, and they looked ready to go another 100k. Not that I would do or suggest that.
My fear with those high mileage plugs is seizing in the head and stripping it during removal.
NGK - thumbs up!
BTW- grammpi, shouldn't you be in Grand Cayman about now?
I'm not even sure what a Grand Caymen is. I'm really liking the the Nissan Cube though. My daughter just bought a new one. I don't care for the exterior looks much, but the amount of interior space in that thing is nothing short of amazing! Talk about getting the most from a given platform size, Nissan has done just that with the Cube. I also love the CVT tranny. But I'm getting off topic here.
Someone asked earlier what the recommended plug change interval was. For the Corolla it's every 30K. Also, someone mentioned the worry of getting the plugs out after they've been in for so long. I always use anti-sieze on the threads, especially since the Corolla's heads are aluminum, and I've yet to have a problem removing the plugs regardless of how long they've been in.
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Some guys on the Mustang site claimed their cars didn't run as well on Champions or didn't run well for long. Others thought they were just fine. The newer Mustangs have a new one-piece plug but it does not fit my 06. I wonder who ever thought a 2 piece plug was a good idea.
Originally Posted By: ChiTDI
BTW- grammpi, shouldn't you be in Grand Cayman about now?
Sorry, I had you confused with this gentleman "GrampsintheSand".
He is lucky enough to be in Grand Cayman, but I do like the "Cube".
OP - yeah change the plugs before they seize!
BTW- grammpi, shouldn't you be in Grand Cayman about now?
Sorry, I had you confused with this gentleman "GrampsintheSand".
He is lucky enough to be in Grand Cayman, but I do like the "Cube".
OP - yeah change the plugs before they seize!
why would ANY sane enginer design a two piece spark plug? even I know better than that.
As it turns out, the new plugs did not cure my misfire problem. I now believe I have a bad plug wire, or wires. The misfire isn't constant; it'll run fine and then it randomly misfires, like one of the plug wires has a pin hole in it and it's occasionaly grounding to a point on the engine. I'm gonna pick up a new set of wires today. I am glad I changed the plugs though because they certainly needed to be changed.
The cooper core champion's that were in my Subie were completely shot at 45K miles, those were from the previous owner, not me. I had NGK V-Power plugs put in it, with the factory part number. I plan on changing these at 40K, even though they will probably last longer than the champion's. My car specs copper core plugs, so I didn't want to take a chance with platinums.
The owner's manual in my '04 Accord recommends changing the OEM iridium plugs at around 120k, and a valve adjustment around the same time. I think I'll probably adjust the valves within the next few months (maybe around 95,000). Most accounts of replacing the original plugs on this engine is that they look very good even past 100k miles.
These NGK iridium plugs are kinda expensive- and I'm kinda broke lately. I'm thinking that when I adjust the valves maybe I'll pull the plugs and have a look. If they look good, maybe I'll just re-gap them and reinstall them with anti-seize... and run them another 50K or so. What do ya'll think?
These NGK iridium plugs are kinda expensive- and I'm kinda broke lately. I'm thinking that when I adjust the valves maybe I'll pull the plugs and have a look. If they look good, maybe I'll just re-gap them and reinstall them with anti-seize... and run them another 50K or so. What do ya'll think?
Originally Posted By: onion
The owner's manual in my '04 Accord recommends changing the OEM iridium plugs at around 120k, and a valve adjustment around the same time. I think I'll probably adjust the valves within the next few months (maybe around 95,000). Most accounts of replacing the original plugs on this engine is that they look very good even past 100k miles.
These NGK iridium plugs are kinda expensive- and I'm kinda broke lately. I'm thinking that when I adjust the valves maybe I'll pull the plugs and have a look. If they look good, maybe I'll just re-gap them and reinstall them with anti-seize... and run them another 50K or so. What do ya'll think?
Bad idea. 7 years or 75,000 for me. I never check,clean,regap,and reinstall old plugs. If an old plug comes out,a new one goes in. You want fewer plug transactions to avoid stripped threads.
The owner's manual in my '04 Accord recommends changing the OEM iridium plugs at around 120k, and a valve adjustment around the same time. I think I'll probably adjust the valves within the next few months (maybe around 95,000). Most accounts of replacing the original plugs on this engine is that they look very good even past 100k miles.
These NGK iridium plugs are kinda expensive- and I'm kinda broke lately. I'm thinking that when I adjust the valves maybe I'll pull the plugs and have a look. If they look good, maybe I'll just re-gap them and reinstall them with anti-seize... and run them another 50K or so. What do ya'll think?
Bad idea. 7 years or 75,000 for me. I never check,clean,regap,and reinstall old plugs. If an old plug comes out,a new one goes in. You want fewer plug transactions to avoid stripped threads.
Originally Posted By: FZ1
Originally Posted By: onion
The owner's manual in my '04 Accord recommends changing the OEM iridium plugs at around 120k, and a valve adjustment around the same time. I think I'll probably adjust the valves within the next few months (maybe around 95,000). Most accounts of replacing the original plugs on this engine is that they look very good even past 100k miles.
These NGK iridium plugs are kinda expensive- and I'm kinda broke lately. I'm thinking that when I adjust the valves maybe I'll pull the plugs and have a look. If they look good, maybe I'll just re-gap them and reinstall them with anti-seize... and run them another 50K or so. What do ya'll think?
Bad idea. 7 years or 75,000 for me. I never check,clean,regap,and reinstall old plugs. If an old plug comes out,a new one goes in. You want fewer plug transactions to avoid stripped threads.
Good idea, especially when working with aluminum heads...
Originally Posted By: onion
The owner's manual in my '04 Accord recommends changing the OEM iridium plugs at around 120k, and a valve adjustment around the same time. I think I'll probably adjust the valves within the next few months (maybe around 95,000). Most accounts of replacing the original plugs on this engine is that they look very good even past 100k miles.
These NGK iridium plugs are kinda expensive- and I'm kinda broke lately. I'm thinking that when I adjust the valves maybe I'll pull the plugs and have a look. If they look good, maybe I'll just re-gap them and reinstall them with anti-seize... and run them another 50K or so. What do ya'll think?
Bad idea. 7 years or 75,000 for me. I never check,clean,regap,and reinstall old plugs. If an old plug comes out,a new one goes in. You want fewer plug transactions to avoid stripped threads.
Good idea, especially when working with aluminum heads...
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