Why does my car schedule have a time interval for spark plug replacement
- Thread starter Paul_Siu
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Originally Posted by Paul_Siu
Back in the old days when I had to change the spark plugs often, I would use a dab of anti-seize and a torque wrench just like Le_bow_ski.
Going back to fouling of spark plugs, driving really short trips will foul the plugs because it doesn't get to burn off the build up on the plugs? What would it take to clear it? Driving 20 minutes monthly? Does it have to be highway miles?
Paul
As for burning the plug foul, I'd think hwy miles at those speeds for 20 min would do it.
In my VW, I'm always feel like I putt-putt around town and stop and go short trips. I should do the same about 2 - 3 times a month.
What I do now about twice a week is after it is warmed up well, I'll burn away from a few traffic lights manual or paddle shifters rather fast but no over-run the speed limit or, slow when light traffic and hard accelerate using the paddle shifters to wind out the rpms a bit.
Back in the old days when I had to change the spark plugs often, I would use a dab of anti-seize and a torque wrench just like Le_bow_ski.
Going back to fouling of spark plugs, driving really short trips will foul the plugs because it doesn't get to burn off the build up on the plugs? What would it take to clear it? Driving 20 minutes monthly? Does it have to be highway miles?
Paul
As for burning the plug foul, I'd think hwy miles at those speeds for 20 min would do it.
In my VW, I'm always feel like I putt-putt around town and stop and go short trips. I should do the same about 2 - 3 times a month.
What I do now about twice a week is after it is warmed up well, I'll burn away from a few traffic lights manual or paddle shifters rather fast but no over-run the speed limit or, slow when light traffic and hard accelerate using the paddle shifters to wind out the rpms a bit.
I put a new set of Motorcraft Iridiums in the Focus last night, at 24,000 miles. Spaced out using anti-sieze. Should I pull them back out now & apply anti-sieze, or can it wait until 50K - 60K miles when I replace them again?
Originally Posted by WylieCoyote
I put a new set of Motorcraft Iridiums in the Focus last night, at 24,000 miles. Spaced out using anti-sieze. Should I pull them back out now & apply anti-sieze, or can it wait until 50K - 60K miles when I replace them again?
The anti-seize should last the life of the plugs, but why are you replacing them at 25k? Does Ford really require replacing iridium every 25k? Is your car modified?
NGK claims theirs don't need any ant-seize, and that their factory-applied coating lasts the full life of the spark plug, which can be over 100k
I put a new set of Motorcraft Iridiums in the Focus last night, at 24,000 miles. Spaced out using anti-sieze. Should I pull them back out now & apply anti-sieze, or can it wait until 50K - 60K miles when I replace them again?
The anti-seize should last the life of the plugs, but why are you replacing them at 25k? Does Ford really require replacing iridium every 25k? Is your car modified?
NGK claims theirs don't need any ant-seize, and that their factory-applied coating lasts the full life of the spark plug, which can be over 100k
Originally Posted by slacktide_bitog
Originally Posted by WylieCoyote
I put a new set of Motorcraft Iridiums in the Focus last night, at 24,000 miles. Spaced out using anti-sieze. Should I pull them back out now & apply anti-sieze, or can it wait until 50K - 60K miles when I replace them again?
The anti-seize should last the life of the plugs, but why are you replacing them at 25k? Does Ford really require replacing iridium every 25k? Is your car modified?
NGK claims theirs don't need any ant-seize, and that their factory-applied coating lasts the full life of the spark plug, which can be over 100k
The car has s slight vibration at idle, something that others on the Focus ST forums have cured by checking & correcting spark plug gap. I went ahead and replaced them instead of gapping the old ones. I'll probably check them again at 50,000.. just wondering now if I shouldn't pull them back out and put anti seize on them.
Originally Posted by WylieCoyote
I put a new set of Motorcraft Iridiums in the Focus last night, at 24,000 miles. Spaced out using anti-sieze. Should I pull them back out now & apply anti-sieze, or can it wait until 50K - 60K miles when I replace them again?
The anti-seize should last the life of the plugs, but why are you replacing them at 25k? Does Ford really require replacing iridium every 25k? Is your car modified?
NGK claims theirs don't need any ant-seize, and that their factory-applied coating lasts the full life of the spark plug, which can be over 100k
The car has s slight vibration at idle, something that others on the Focus ST forums have cured by checking & correcting spark plug gap. I went ahead and replaced them instead of gapping the old ones. I'll probably check them again at 50,000.. just wondering now if I shouldn't pull them back out and put anti seize on them.
No reason why you should need to pull iridium plugs prior to 100K...I've seen multiple examples at 150K+ in near perfect condition. Platinum, I would say 60K-80K range to be safe. Spark plugs in newer applications are darn near a lifetime part now, unless something else is wrong causing fouling or whatnot.
Modern spark plugs come up to temperature very quickly to fluff off deposits, and fuel-injection systems are typically very efficient. Practically the only way you are going to foul a spark plug nowadays is if you 1) don't change the plugs, and 2) are burning significant oil and/or using a carburetor, and/or 3) have an issue with the ignition system (misfire).
Originally Posted by Paul_Siu
I notice that my car manual said to replace spark plug every 60,000 miles or 60 months. Why would there be a time interval replacement schedule. Spark plugs are made of ceramic and metal. I don't see it going bad over time if you don't drive a lot of miles like tires.
Paul
When your engine was designed the engineers chose a specific type of spark plug with an average useful lifespan in this application. Without pulling spark plugs you can't evaluate their exact condition. If you go to the trouble of removing them you may as well replace them. I'm not a fan of putting used spark plugs back in because the crush washers are ideally one-time use only. Yes, you "can" reuse a used spark plug. As has been mentioned the longer spark plugs remain in the head, the more likely the threads will seize. I have never noticed galvanic corrosion but I suppose in a very humid or wet climate that can become an issue. In a dry climate, in the absence of an electrolyte, I don't see how galvanic corrosion could become be a problem. I follow the manufacturer's recommended interval for replacing spark plugs. I also replace spark plug wires, where still applicable, every 120k miles.
I notice that my car manual said to replace spark plug every 60,000 miles or 60 months. Why would there be a time interval replacement schedule. Spark plugs are made of ceramic and metal. I don't see it going bad over time if you don't drive a lot of miles like tires.
Paul
When your engine was designed the engineers chose a specific type of spark plug with an average useful lifespan in this application. Without pulling spark plugs you can't evaluate their exact condition. If you go to the trouble of removing them you may as well replace them. I'm not a fan of putting used spark plugs back in because the crush washers are ideally one-time use only. Yes, you "can" reuse a used spark plug. As has been mentioned the longer spark plugs remain in the head, the more likely the threads will seize. I have never noticed galvanic corrosion but I suppose in a very humid or wet climate that can become an issue. In a dry climate, in the absence of an electrolyte, I don't see how galvanic corrosion could become be a problem. I follow the manufacturer's recommended interval for replacing spark plugs. I also replace spark plug wires, where still applicable, every 120k miles.
Originally Posted by Astro14
Mileage wears out the electrodes...however...steel sparkplug shells screwed into aluminum heads will eventually corrode until they're impossible to remove.
Ask the guys who owned 5.4 Ford Triton engines.
I agree, of course that does not make me right. But from what I have been taught what Astro14 is saying. Leaving the plugs in too long can sorta freeze them in place.
I still use a little anti seize. Just a teeny tiny amount.
Mileage wears out the electrodes...however...steel sparkplug shells screwed into aluminum heads will eventually corrode until they're impossible to remove.
Ask the guys who owned 5.4 Ford Triton engines.
I agree, of course that does not make me right. But from what I have been taught what Astro14 is saying. Leaving the plugs in too long can sorta freeze them in place.
I still use a little anti seize. Just a teeny tiny amount.
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Originally Posted by tbm5690
No reason why you should need to pull iridium plugs prior to 100K...I've seen multiple examples at 150K+ in near perfect condition. Platinum, I would say 60K-80K range to be safe. Spark plugs in newer applications are darn near a lifetime part now, unless something else is wrong causing fouling or whatnot.
The two 4 bangers in my life are a Fusion Hybrid and a Cruze turbo. Waited to 120k on both. If I had it to do over I'd probably go 80k … not because of the condition the plugs were in - but how tight they were coming out. On the Ford I actually blew the pocket clean with air and sprayed a bit of silicone in there … tight the whole way out.
My V8's will go 100k … they are in open space … not down in a blind hole.
No reason why you should need to pull iridium plugs prior to 100K...I've seen multiple examples at 150K+ in near perfect condition. Platinum, I would say 60K-80K range to be safe. Spark plugs in newer applications are darn near a lifetime part now, unless something else is wrong causing fouling or whatnot.
The two 4 bangers in my life are a Fusion Hybrid and a Cruze turbo. Waited to 120k on both. If I had it to do over I'd probably go 80k … not because of the condition the plugs were in - but how tight they were coming out. On the Ford I actually blew the pocket clean with air and sprayed a bit of silicone in there … tight the whole way out.
My V8's will go 100k … they are in open space … not down in a blind hole.
These squeaked pretty loudly coming out, but didn't feel bound in any way. Threads looked really good, center electrodes had a very thin coat of black on them, except the very tip, which was shiny silver. "Iridium" must be tough, because the electrodes look like they come to a needle point at the end.
Motorcrafts aren't prohibitively expensive, so I just chose to replace while I was going to have them out anyway.
Motorcrafts aren't prohibitively expensive, so I just chose to replace while I was going to have them out anyway.
