Changing spark plugs how long?

[keynes]

Hi

just wondering how long would a competent workshop take to change a set of spark plugs, whats peoples experiences?

I am getting fluids - oil, clutch, brake - changed at the same time

Happy motoring!

 

[solidol]

Slow pace 1/2h job max. Most of the time spent on the rear bank.

 

[Old Guy]

Competent workshop does not necessarily equal workshop with NSX experience. If you have a technician who has done this on an NSX a few times and doesn't have to look at the service manual or puzzle stuff out, then an incremental 30 minutes should easily cover it if they are doing other things on the car. If I were to do 'just the plugs' on my car, from the time I laid out the covers on the fenders to protect the paint until I folded the covers back up again there is no way I would be under 60 minutes. But, I am a bit anal and always gap check my pre gapped sparkplugs and slather lots of anti seize on the plug threads and am paranoid about fumbling and dropping things into the engine compartment because 50% of the time they never seem to come out the bottom :smile:.

 

[drew]

IMHO, 30 min is rushed and 60 is good. And I can see a shop charging 2 hours. There are a fair amount of bolts, it is easy to damage a cover, and any problems can be catastrophic.

re:antiseize
https://www.ngkplugpro.ca/content/contentfiles/pdf/NGKSP-0907-1R-Anti-SeizeonSparkPlugs.pdf

I still put it on, but there you go.

 

[solidol]

I do compression test every two years or so. Half an hour is for actual r&r not including prep work. Whoever charging you for more than 1h is taking advantage.

Never used antiseize with coated plugs. If you choose to do so make sure to use the right one every time you deal with aluminum head. Put a coat of new engine oil with your finger and call it a day.

 

[Old Guy]

Well, that is interesting about the plated plugs. In terms of over torqueing that problem exists whether the lubrication is provided by engine oil or anti seize. I admit to liking a little lubricant / anti seize on the threads because when you are running the plug into a deep plug hole blind it makes it much easier to feel if its not threading in correct. Aluminum is so soft and easy to bugger up.

I had never seen a reference to torque angle specified for sparkplugs; but, here you go

https://www.denso.com/global/en/pro...vice-parts-and-accessories/plug/basic/torque/

 

[Honcho]

I think the Acura book time for this job is 1 hour. In any event, the last time I did it, it took about 45 minutes taking my time, being meticulous, using a torque wrench etc. Agree with [MENTION=26435]Old Guy[/MENTION] that you should be very careful threading the plug. I trick I use is to rotate the plug counter clockwise first. When you feel it "hop," stop. You now know you've got a good thread engagement. I then tighten by hand and finish with a torque wrench. I've always put them in dry.

 

[Lude_2_NSX]

1 hour of labor would be realistic

 

[ralph cerbone]

IMHO, 30 min is rushed and 60 is good. And I can see a shop charging 2 hours. There are a fair amount of bolts, it is easy to damage a cover, and any problems can be catastrophic.

re:antiseize
https://www.ngkplugpro.ca/content/contentfiles/pdf/NGKSP-0907-1R-Anti-SeizeonSparkPlugs.pdf

I still put it on, but there you go.

old habits die hard ,I understand it but it totally not needed or recommended . NGK started warning against antiseize on their 10 mm plugs,snowmobile and motorcycle plugs . The problem with those plugs were installers were exceeding the torque capacity of those plugs because of the lube resulting in broken plugs . You thread plug in by hand until it sealing washer seats then torque or turn to proper angle , shown on plug box ,thats it .

 

[Kaz-kzukNA1]

Bit off-topic but hope this info will help others.

NGK and Denso don't recommend the use of anti-seize thread compound because of the risk of over-torqueing the spark plug.
However, with the production car engine, it is almost impossible creating oil free cyl head plug hole thread or clean plug gasket mating surface.

For the clarification, Honda DO specify the use of anti-seize when installing the spark plug but with specific torque spec depending on the engine and the plug spec.
It is clearly specified in the workshop manual for each models.

For NSX, if using OEM specified platinum plug from NGK/Denso, please APPLY anti-seize and use the torque wrench set at 18Nm.
This will result in the torque spec range from NGK and Denso of 25 - 30Nm when installed without the use of anti-seize.

If you don't have the torque wrench, using the angle method will achieve very good result with/without the anti-seize.

If using different spec aftermarket plug, please pay extra attention to the top terminal shape, gasket material and the service interval.


Kaz

 

[goldNSX]

For NSX, if using OEM specified platinum plug from NGK/Denso, please APPLY anti-seize and use the torque wrench set at 18Nm.
This will result in the torque spec range from NGK and Denso of 25 - 30Nm when installed without the use of anti-seize.

Kaz, thanks for the valuable information.

I've once applied 18 Nm with near to none anti-seize and it felt a little bit loose when I've removed them the next time.

 

[ralph cerbone]

Bit off-topic but hope this info will help others.

NGK and Denso don't recommend the use of anti-seize thread compound because of the risk of over-torqueing the spark plug.
However, with the production car engine, it is almost impossible creating oil free cyl head plug hole thread or clean plug gasket mating surface.

For the clarification, Honda DO specify the use of anti-seize when installing the spark plug but with specific torque spec depending on the engine and the plug



spec.
It is clearly specified in the workshop manual for each models.

For NSX, if using OEM specified platinum plug from NGK/Denso, please APPLY anti-seize and use the torque wrench set at 18Nm.
This will result in the torque spec range from NGK and Denso of 25 - 30Nm when installed without the use of anti-seize.

If you don't have the torque wrench, using the angle method will achieve very good result with/without the anti-seize.

If using different spec aftermarket plug, please pay extra attention to the top terminal shape, gasket material and the service interval.


Kaz

Kaz iam well aware of what honda recommends (nsx manual and my pilots manual) "apply a SMALL QUANTITY of anti-seize compound to the plug threads before installing each plug " . According to an NGK rep i met at a trade & educational show the problem is WHATS A SMALL QUANTITY . I questioned him about NGK's recommendation of no anti-seize because of their trivalent coating was contrary to what my manuals said . His response was it is no longer needed , would a small dab hurt applied to the beginning threads ,no. Their concern is the product is sold to the trade industry and diy's who may not properly install them.NGK also has a tech bulletin where they explain their trivalent zinc -chromate shell and advise no anti seize . So whats the answer , do what you think is right just remember to torque properly and more is not better

 

[Old Guy]

Kaz iam well aware of what honda recommends (nsx manual and my pilots manual)

Interesting coincidence, I also own an NSX and Pilot.

I don't drive my individual vehicles a lot so I always time out on maintenance. When I got around to replacing the plugs on my Pilot at a little over 7 years after purchase, my subjective assessment at the time was that the factory installed spark plugs seemed to require an awful lot of torque to break them loose. This was a subjective assessment and may have been colored by the fact that particularly on the back cylinders you need to be standing on a stool to reach over the engine so its awkward and you are using a socket extension (which always introduce a little paranoia inducing wobble) and you are definitely doing it blind. The plugs that came out did not show any obvious signs of galling; but, given my perception of the break-loose force required and that I always max out (or slightly over max) the time that they are in the engine, the new ones went in with anti seize. The plugs are due for replacement again this summer so I may get a chance to find out whether the anti seize makes any difference.

The one advantage of putting the sparkplugs in 'dry' that I can see has to do with the accuracy of the torque measurement. I suspect that my 'click' style torque wrench probably has a little non linearity / dead band at its lower setting limit which conspires against getting an accurate torque measurement at the bottom of its operating range. Click style 3/8" torque wrenches that typically have a bottom torque measurement of 10 ft-lb (20 seems more common) probably don't do a very good job of measuring out the 13 ft-lb specified in the Honda manual. However, chances are that their accuracy is better at the 18-21 ft-lb measurement that NGK specifies for a plug going in dry. If you are going to use the torque wrench method as opposed to the angle method (which really only works with a fresh washer) with a lubricated thread you really need a micro adjustable torque wrench measuring in in-lb. I have a prehistoric beam style torque wrench which reads to 250 in-lb max so the 13 ft-lb / 156 in-lb spark plug torque is nicely in the middle of its calibration range which gives me a warm and fuzzy feeling. I have been tempted to modernize; but, the common 3/8 drive click style micro adjustables typically stop at 150 in-lb. There are some nice ones that go higher; but, all seem to come with a not so nice price so I remain firmly in the prehistoric era.

An interesting discussion!

 

[Mac Attack]

Interesting coincidence, I also own an NSX and Pilot.

I don't drive my individual vehicles a lot so I always time out on maintenance. When I got around to replacing the plugs on my Pilot at a little over 7 years after purchase, my subjective assessment at the time was that the factory installed spark plugs seemed to require an awful lot of torque to break them loose. This was a subjective assessment and may have been colored by the fact that particularly on the back cylinders you need to be standing on a stool to reach over the engine so its awkward and you are using a socket extension (which always introduce a little paranoia inducing wobble) and you are definitely doing it blind. The plugs that came out did not show any obvious signs of galling; but, given my perception of the break-loose force required and that I always max out (or slightly over max) the time that they are in the engine, the new ones went in with anti seize. The plugs are due for replacement again this summer so I may get a chance to find out whether the anti seize makes any difference.

The one advantage of putting the sparkplugs in 'dry' that I can see has to do with the accuracy of the torque measurement. I suspect that my 'click' style torque wrench probably has a little non linearity / dead band at its lower setting limit which conspires against getting an accurate torque measurement at the bottom of its operating range. Click style 3/8" torque wrenches that typically have a bottom torque measurement of 10 ft-lb (20 seems more common) probably don't do a very good job of measuring out the 13 ft-lb specified in the Honda manual. However, chances are that their accuracy is better at the 18-21 ft-lb measurement that NGK specifies for a plug going in dry. If you are going to use the torque wrench method as opposed to the angle method (which really only works with a fresh washer) with a lubricated thread you really need a micro adjustable torque wrench measuring in in-lb. I have a prehistoric beam style torque wrench which reads to 250 in-lb max so the 13 ft-lb / 156 in-lb spark plug torque is nicely in the middle of its calibration range which gives me a warm and fuzzy feeling. I have been tempted to modernize; but, the common 3/8 drive click style micro adjustables typically stop at 150 in-lb. There are some nice ones that go higher; but, all seem to come with a not so nice price so I remain firmly in the prehistoric era.

An interesting discussion!

What a lot of people don't realize is that after a "click" on their torque wrench, they don't immediately back off before exerting additional torque, and therefore, over-torque. There is an art to using a torque wrench. You don't rush up on the torque - you begin backing off as you approach your setpoint. This is especially important for weak threads where there isn't a lot of design margin.

For a lot of the little 10 ft-lb stuff on aluminum or magnesium I use something like these. Because of space limitations you sometimes have to have a variety of different extension lengths though to accommodate them:
https://www.toolsid.com/oem-tools/3-8-drive-digital-torque-adapter-mpn-25684.html?view=259625&gclid=EAIaIQobChMIspTfxdPF4AIVkhh9Ch3NsQ7xEAQYBSABEgINX_D_BwE

Granted, most only have a minimum calibration to 20 ft-lbs, but I've taken them into work and have had mine checked down to 10 ft-lbs. The ones I have also have an audible indicator and even red/green leds to let you know when you've reached your pre-determined torque.

 

[goldNSX]

A mechanic knows what 10 Nm and 20 Nm feel like. I'd bet I could be within -10% to 0 without a torque wrench. I only use one on critical bolts/areas esp. where the sequence is important. On the bolts on the valve cover I've torqued recently by hand I went below the torque recommendation of 10 Nm to about 8 Nm which is sufficient. I also checked it with a torque wrench and re-torqued it with 10 Nm, loosened it again and went back to about 8 Nm. 10 Nm feels insane and unnecessary IMHO. Yes, I use a calibrated torque wrench with a print-out for values between 5 and 25 Nm, expensive tool too.

That tool on toolsid.com is far too bulky and laborious, I'm sorry to say, don't get me wrong on this. When operating with a 'chlicking' torque wrench you have an idea of when the torque is reached and slow down torquing until it clicks. To exclude that it clicked accidentially (or too early) I torque the same bolt once again. If it doesn't move it's ok. Just take your time but it's easier and faster than handling any additional tools.

 

[Mac Attack]

Thomas, a "professional" mechanic should know the difference between 10 and 20 Nm, but then again, I'm constantly surprised by simple mistakes from "professionals..." including damaged threads.

While you know what you're doing, the typical weekend warrior home mechanic doesn't know the difference between 10 and 20 Nm, especially if they are in an awkward position wrenching on something they're not normally used to.

Yes, those electronic boxes are slightly clumsy, but when they cover a range of 10 to 150+ ft-lbs and can fit on your small ratchet or a larger breaker bar for leverage when you need it, I think they are worth it. Also, you don't need to spend time twirling the handle to go between torque values - You just look at the readout as you torque.

I'm not a professional, but I used one of those to completely build my NSX engine. It was used for everything from the bolts into the fragile magnesium valve covers to the head studs. Basically, everywhere except for tightening up the oil pan and the rod bolts. A $30 tool replaced a small fortune in torque wrenches so I was happy with that! It's cheap, accurate, and takes up less space, so I typically recommend them to anyone looking for their first-time torque wrenches. My $0.02....

 

[goldNSX]

Dave, I'm with you on this in most aspects.

The main reason dealer mechanics mess up threads is mainly due to the expected output they have to deliver and sometimes to some degree of carelessness. I work maybe half as fast as any tech and pay attention to details maybe double than any tech out there. So I'm 4 times slower than any mechanic and would have gotten fired by every single dealer on earth (maybe except in Africa?).

For a novice, either tools will work and DO help for sure. For the advanced ones I'd go the more expensive route and buy a serious torque wrench. I can't justify any tools that let me work even slower. :wink:

 

[Mac Attack]

So I'm 4 times slower than any mechanic and would have gotten fired by every single dealer on earth (maybe except in Africa?).

I'm the same way (perhaps even slower if I'm teaching my kids to do it). That's why I didn't want to respond to this thread and skew the range. I will, however, contribute to de-railing it!

 

[Lude_2_NSX]

I've always used the "two-finger" trick. Basically as i'm tightening the spark plug, I put my thumb on the head of the socket wrench and instead of the rest of my hand on the handle, I only use two fingers. It really limits the torque that can be applied. Learned that decades ago, and I has stuck with me...

 

[Old Guy]

So, after having new sparkplugs sitting around for a while, I finally got around to changing them today and I want to update my post #3 time estimate for replacement. No way on the 60 minutes. By the time I finished it was more like 2+ hours. I did have some complicating factors:

- I have a targa so it has the triangle brace which reduces the clean sailing that the coupe owners get on the front cylinders
- plugs 1, 3 and 4 were definitely stuck in there. I had to use a 1/2" breaker bar to get them out and I was paranoid about breaking things. There was a very large bang when they finally released. New ones definitely went in with anti seize.
- my new 250 in-lb torque wrench, despite being for low torque 'small' applications was just a little bit too long for convenient use on the plugs. You only get about 25 deg of motion before the wrench runs into something.
- a 3 " long 3/8" extension is too short (with my spark plug socket) to fit into the wells. My 6" extension works; but, you have to insert the socket and extension separately into the well and then attach the wrench. You can't fit everything in attached together. A 4.5" extension would likely allow you to do this in one step speeding things up.
- somebody switched the front and back coil covers which kind of messed up the cover gaskets and I spent some time refitting and gluing the gasket into place.
- did I mention anti - seize? Spent a lot of time applying it to everything in site.
- applied silicone dielectric grease to the coil boot, the base gasket on the coil and the 3 pin (OBDII) low voltage plug on the coil. The ribbed rubber seals in those plugs stick like crazy so I am hoping that the silicon grease will ease removal in the future.

Went through 4 nitrile gloves after catching them on pokey bits in the engine bay. I think I would have been able to do this in 30 minutes if the engine had been out of the car. Engine in the car - no way.

On the positive side, this time everything I dropped down into the engine bay made its way to the garage floor. Nothing disappeared into the NSX.

 

[solidol]

I would advise against using torque wrench with 250 range on low tq jobs.

 

[Miner]

I would advise against using torque wrench with 250 range on low tq jobs.

In-lbs. I thought the same thing and then it made sense when I re-read.

 

[solidol]

In-lbs. I thought the same thing and then it made sense when I re-read.

Ah sorry, in/lb, missed that reading on the phone.

 

[ralph cerbone]

So, after having new sparkplugs sitting around for a while, I finally got around to changing them today and I want to update my post #3 time estimate for replacement. No way on the 60 minutes. By the time I finished it was more like 2+ hours. I did have some complicating factors:

- I have a targa so it has the triangle brace which reduces the clean sailing that the coupe owners get on the front cylinders
- plugs 1, 3 and 4 were definitely stuck in there. I had to use a 1/2" breaker bar to get them out and I was paranoid about breaking things. There was a very large bang when they finally released. New ones definitely went in with anti seize.
- my new 250 in-lb torque wrench, despite being for low torque 'small' applications was just a little bit too long for convenient use on the plugs. You only get about 25 deg of motion before the wrench runs into something.
- a 3 " long 3/8" extension is too short (with my spark plug socket) to fit into the wells. My 6" extension works; but, you have to insert the socket and extension separately into the well and then attach the wrench. You can't fit everything in attached together. A 4.5" extension would likely allow you to do this in one step speeding things up.
- somebody switched the front and back coil covers which kind of messed up the cover gaskets and I spent some time refitting and gluing the gasket into place.
- did I mention anti - seize? Spent a lot of time applying it to everything in site.
- applied silicone dielectric grease to the coil boot, the base gasket on the coil and the 3 pin (OBDII) low voltage plug on the coil. The ribbed rubber seals in those plugs stick like crazy so I am hoping that the silicon grease will ease removal in the future.

Went through 4 nitrile gloves after catching them on pokey bits in the engine bay. I think I would have been able to do this in 30 minutes if the engine had been out of the car. Engine in the car - no way.

On the positive side, this time everything I dropped down into the engine bay made its way to the garage floor. Nothing disappeared into the NSX.

Based on your use of a breaker bar to remove the plugs and coil covers being backwards tells me someone who has no clue of what he's doing , the only time I ever had to use a 1/2 breaker bar is on tapered compression seat plugs . I am sure you know what I mean , you should be thankful he didn't use antiseize , the threads would have been pulled .

 

[Old Guy]

The work was done by an Acura service tech back in 2010. I can see the coil cover mix up because the coil covers fit front or back just fine, it is the gasket location that ends up wrong if you mix them up. Easy enough to forget if you don't do an NSX on a regular basis. The only reason I knew is that every time I do something on the NSX the service manual is always open on the relevant pages.

I might have been able to get the plugs out with a 3/8 breaker bar; but, your hands are really 'down in there' and you don't have a lot of leverage. The 1/2 bar was long enough that your hands are clear of most of the pokey / sharp stuff; but, it sure did release with a bang. I gave it a sphincter factor of about 7.5 out of 10! Also unusual was the fact that #5 came out fairly easily which given the recent post by [MENTION=4272]liftnot[/MENTION] about blowing the #5 plug out of the engine had me a little concerned. However, there was no sign of combustion leakage past the threads.

The sparkplugs that came out of the NSX were NGK Iridium, the plugs that came out of my Pilot were the factory installed NGK platinum (which also required a hell of a lot of grunt to get out). Right now I am not feeling a lot of love for NGK's special plating which supposedly eliminates the need for anti seize. Perhaps the problem is that I always max out or exceed the recommended time for replacement because my mileage use is low.