spark plugs.

Status
Not open for further replies.
I had to go through a number of replies to find my own answer- taking them out for inspection at least every 5oK miles helps to prevent them from getting frozen into the alloy heads that are omnipresent these days. The boots/coil packs that are attached to the plugs these days also can stick and get torn when pulled off- so be careful. I use a tiny bit of antisieze on the plug threads and a bit of dielectric grease on the coil pack where it fits on the plug.
 
Too bad you didn't have OEM AC Delco, made by NGK. They already have a coating on them to prevent seizure.

Our fleet has had aluminum heads for a LONG time, never any issues with removal even after double the factory interval. And no fragile coil issues either.
 
Originally Posted By: artificialist
I find that many 100,000 mile plugs are not actually going more than 60,000 miles. Also, early replacement is good because the wider the park gap gets, the more it stresses the ignition coils. So change plugs early, you will save money long term. I had a friend who had to replace an ignition coil in a Volkswagen VR6, and no matter where he looked, it was extremely expensive.


Sorry your friend's experience hit my bull's meter a bit.

Should you change a spark plug before it's required interval? No, unless there is a problem. Or you don't trust the previous owner of the car.

Ignition coils are all controlled by the ECU now and are perfectly capable of standing a little extra gap. Unless you are misfiring like crazy which as already noted causes the ECU to flash the MIL lamp even at the slightest you worry to much.

Now I will advocate that you should pull the plugs & inspect them if it is easy enough but otherwise let them be until they need to be changed.

VR6's used either one coil for the 12v or coil on plug for the 24v.

Your friends coil pack didn't die from spark plugs not being changed it died from age. They can crack and misfire and not changing the spark plugs has nothing to do with it. Those early 12v were not being used after 2000 much so that is why the part was costly. Older car, older part not widely used anymore=higher price.

However if you look well enough you can find a decent deal on them instead of the OEM $400+ price. It looks like now they are under $200 for a quality replacement. Cheap it is not but it had nothing to do with spark plugs, just a bad part from the factory like A LOT of things these days.
 
KitaCam said:
The other "advantage" of changing plugs @ or near 100k and say 8 years is getting them out before they become a near-permanent part of the engine...freezing in their socket...changing 6 plugs @ $40-50/100k miles is a no brainer....that's about 1/10 the price of oil changes (@ $50/10k) over those miles...(less for those who eke out an few extra miles on their OCI, a lot less for DIYers)...[/quote

Seen alot of frozen plugs. Could cost alot to get that stuck plug out.]
 
I have also read...okay, ON THE NET, I know...that once a plug has been removed it should NOT be reinserted...that it should be replaced...the reason being that the ceramic insulator may be compromised in the removal process...I don't know if this is so, but as has been said, read the manual, change as recommended, (or 10-15% earlier if you must), sleep well...
 
Last edited:
Originally Posted By: Clevy
My fox is a piece of cake to get at the plugs. So changing them slightly ahead of schedule doesn't bother me. The 2V and 4V plugs aren't that bad either so again I like to fiddle.
My hemi was an absolute nightmare. I originally called the dealer because I was just going to have them do it.
For low grade cheap copper plugs they told me over 600 including the parts(I forget the exact cost). I told them over my cold dead body will I pay that kind of money for a couple of hour job.
Well it took me 6 hours to change 16 plugs. The ones behind the brake reservoir were a total nightmare. There was no room to have my socket,extension,swivel and ratchet all assembled and slide in the hole. Nope. I had to assemble each piece,blind,so it was all by feel,and re-install was the same scenario.
There are 5 iirc that are a pain because of the brake booster so the ones closest to the firewall on the driver side,but only 2 on the passenger side were difficult.
When I was done I reflected on the effort,frustration and pain from getting poked everywhere because I had to lay on top of the engine and I re-considered the quoted price and felt it was worth every penny for me to not have to do it again,expense vs reward,and the expense was worth the reward of not having to do it.
I used platinum/iridium plugs so I could take advantage of the extra time in between plug changes.

I do like standard copper plugs in cars that are easy to change. Over time we don't notice the loss of instantaneous response,the speed of start up,ease of passing and those couple of mpg lost due to less than perfect plugs however once changed we all notice how much better the engine runs,so with cheap copper plugs I don't spend alot to maintain that level of responsiveness,and I really can't tell that they were changed.
I feel that I rather maintain top level of performance,rather then keep the platinums in or longer,and they gradually lose their performance,but because they do last longer I just accept the slug my motor becomes.

Lol at Clevy, I have went 16 rounds with the Hemi twice doing spark plugs. won both times but was severely beaten, battered and bruised.
6 hrs. is making pretty good time by the way.
 
Originally Posted By: coolbird101
Originally Posted By: Clevy
My fox is a piece of cake to get at the plugs. So changing them slightly ahead of schedule doesn't bother me. The 2V and 4V plugs aren't that bad either so again I like to fiddle.
My hemi was an absolute nightmare. I originally called the dealer because I was just going to have them do it.
For low grade cheap copper plugs they told me over 600 including the parts(I forget the exact cost). I told them over my cold dead body will I pay that kind of money for a couple of hour job.
Well it took me 6 hours to change 16 plugs. The ones behind the brake reservoir were a total nightmare. There was no room to have my socket,extension,swivel and ratchet all assembled and slide in the hole. Nope. I had to assemble each piece,blind,so it was all by feel,and re-install was the same scenario.
There are 5 iirc that are a pain because of the brake booster so the ones closest to the firewall on the driver side,but only 2 on the passenger side were difficult.
When I was done I reflected on the effort,frustration and pain from getting poked everywhere because I had to lay on top of the engine and I re-considered the quoted price and felt it was worth every penny for me to not have to do it again,expense vs reward,and the expense was worth the reward of not having to do it.
I used platinum/iridium plugs so I could take advantage of the extra time in between plug changes.

I do like standard copper plugs in cars that are easy to change. Over time we don't notice the loss of instantaneous response,the speed of start up,ease of passing and those couple of mpg lost due to less than perfect plugs however once changed we all notice how much better the engine runs,so with cheap copper plugs I don't spend alot to maintain that level of responsiveness,and I really can't tell that they were changed.
I feel that I rather maintain top level of performance,rather then keep the platinums in or longer,and they gradually lose their performance,but because they do last longer I just accept the slug my motor becomes.

Lol at Clevy, I have went 16 rounds with the Hemi twice doing spark plugs. won both times but was severely beaten, battered and bruised.
6 hrs. is making pretty good time by the way.


Really? That plug change almost drove me to drink again.
Hehehe
 
Originally Posted By: KitaCam
I have also read...okay, ON THE NET, I know...that once a plug has been removed it should NOT be reinserted...that it should be replaced...the reason being that the ceramic insulator may be compromised in the removal process...I don't know if this is so, but as has been said, read the manual, change as recommended, (or 10-15% earlier if you must), sleep well...

Compromised just from removing and checking a plug? I can see it if one drops the plug and it hits the garage floor. I wouldn't want to chance a dropped plug, visual damage or not.
 
I take them out and gap them every 30k, single plat for copper/single plat application, double plat for waste spark application, iridium for iridium application.

So far so good.
 
Originally Posted By: PandaBear
I take them out and gap them every 30k, single plat for copper/single plat application, double plat for waste spark application, iridium for iridium application.

So far so good.

Some engines are easy to remove and re-install spark plugs so your way is reasonable. Some engines, especially the V6 and V8, are very time consuming in removing spark plugs such that changing it every 80-100k miles is better.
 
The crush washers are a one-time use, so you are not supposed to remove/re-install plugs.

My Prius calls for its first plug change at 120k, and I have no plans to touch it until then. Of all the Iridium plugs that I've recently changed at the ~110k mark, all of them could have probably gone twice as long with no performance issues.
 
Originally Posted By: The Critic
The crush washers are a one-time use, so you are not supposed to remove/re-install plugs.

My Prius calls for its first plug change at 120k, and I have no plans to touch it until then. Of all the Iridium plugs that I've recently changed at the ~110k mark, all of them could have probably gone twice as long with no performance issues.


I had the same experience @ 100k...I figure to have the Kitacam for 100k-200k miles so it will need maybe one more change of iridium plugs over the rest of my time with it....seems like the simplist PM it will ever need.
 
Originally Posted By: The Critic
The crush washers are a one-time use, so you are not supposed to remove/re-install plugs.

My Prius calls for its first plug change at 120k, and I have no plans to touch it until then. Of all the Iridium plugs that I've recently changed at the ~110k mark, all of them could have probably gone twice as long with no performance issues.


Great point, but what about the gazillions of us with tapered seat plugs?
 
I've reused crush washer plugs dozens of times without issue, don't believe everything you read...
 
Originally Posted By: TFB1
I've reused crush washer plugs dozens of times without issue, don't believe everything you read...


I thought the same thing.

For many years I never saw anyone replace the crush washers.
Never witnessed a problem.
 
Originally Posted By: expat
Originally Posted By: TFB1
I've reused crush washer plugs dozens of times without issue, don't believe everything you read...


I thought the same thing.

For many years I never saw anyone replace the crush washers.
Never witnessed a problem.


The purpose of a crush washer in any application, is to provide a one-time sacrificial seal. Whether you have success in re-using the washer is irrelevant, as the washer was never intended to be re-used multiple times. Personal experience and correct procedure can sometimes be two different things, and one should not advocate for others to blatantly ignore the established rules.
 
Originally Posted By: SteveSRT8
Originally Posted By: The Critic
The crush washers are a one-time use, so you are not supposed to remove/re-install plugs.

My Prius calls for its first plug change at 120k, and I have no plans to touch it until then. Of all the Iridium plugs that I've recently changed at the ~110k mark, all of them could have probably gone twice as long with no performance issues.


Great point, but what about the gazillions of us with tapered seat plugs?

Since there's no crush washer, I suppose that you are OK to remove/reinstall the plugs as you wish, but the sacrificial anti-corrosive coating is only good for one "cycle." So, if you r/r the plugs, you'll probably have to put a coat of anti-seize on the threads.
 
Status
Not open for further replies.
Back
Top