Spark Plug change DIY
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Joined: Apr 2012
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I just bought NGK Iridium IFR7G-11KS and they are supposed to be factory gapped @ .044, with a -.004 acceptable deviation. Mine were pulled out of the box @ .048, .048, .047, and .046. It's easy to measure and gap without damaging the center electrode. NGK's website says it may be necessary to gap the plugs to manufacturer specifications and I wouldn't install plugs with inconsistent gaps.
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Joined: Sep 2008
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Thank you for this tutorial.
I'd just like to comment that after extensive research, here are some little known facts:
A lot of people debate about Iridium vs Platinum, or even worse, copper plugs. The head/block is aluminum, so copper plugs with their low life-expectancy are a big no-no. The car runs much smoother for me now that stock plug is back, with the proper gap. Unfortunately since you can ONLY order these from the Honda dealer, most people are using the wrong plugs. The correct plugs are special order folks. Summary: Order from the Honda dealer, look for the red box, part number 98079-571BH.
I'd just like to comment that after extensive research, here are some little known facts:
- Factory plug (at least for AP1) is the NGK PFR7G-11S
- NGK PFR7G-11S is ONLY available from the Honda dealer, part number 98079-571BH
- NGK PFR7G-11S are specifically pre-gapped at 0.039 from Honda, what the engine was designed for--other plugs are the WRONG GAP
- Billman does NOT recommend gapping these pre-gapped plugs--they should come perfectly gapped from the dealer
- NGK 98079-571BH is recommended for 75k-100k intervals
- The "S" stands for washer--the washer was added because a lot of plugs from the early years were backing out and damaging the engines
- IMPORTANT: Proper torque is between 20-22 foot-lbs (as stated by Billman)
A lot of people debate about Iridium vs Platinum, or even worse, copper plugs. The head/block is aluminum, so copper plugs with their low life-expectancy are a big no-no. The car runs much smoother for me now that stock plug is back, with the proper gap. Unfortunately since you can ONLY order these from the Honda dealer, most people are using the wrong plugs. The correct plugs are special order folks. Summary: Order from the Honda dealer, look for the red box, part number 98079-571BH.
Joined: Oct 2008
Posts: 1,113
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From: San Francisco
Here's the 2006 owner's manual for your car @ http://techinfo.honda.com/rjanisis/p...u/S20606OM.pdf (page 196/198)
NGK: PFR7G-11S
Honda part number 98079-571BH.
The argument I was making above, in case it wasn't clear, is that you can only buy these specifically-gapped plugs from the Honda dealer, in a red box.
Joined: Oct 2009
Posts: 29,878
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From: Ontario Canada
Honda OEM plugs start out with .039" gaps just so they won't reach the service limit of .051" overly quick, since they are intended to remain in use for 100k miles. My factory plugs were past the service limit gap (.051") at 55k miles. I'm not a fan of leaving plugs in an engine for 100k miles unchecked. An NGK plug that ends in an 11 is designed for a gap of .043" (1.1mm) to maintain a level ground electrode.
I'll put plugs in with gaps of .043" . I prefer Iridium over plats to reduce center electrode erosion over time. I'm putting in a fresh set of NGK BRK7EIX-11 Hyper Iridiums as we speak - they feature a fine wire center electrode with a tapered ground electrode that does not extend past the outer edge of the center electrode. Pic below. Just my preference.
I'll put plugs in with gaps of .043" . I prefer Iridium over plats to reduce center electrode erosion over time. I'm putting in a fresh set of NGK BRK7EIX-11 Hyper Iridiums as we speak - they feature a fine wire center electrode with a tapered ground electrode that does not extend past the outer edge of the center electrode. Pic below. Just my preference.
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Joined: Mar 2015
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hi guys,
1. I note NGK PFR7G-11S is the correct (i.e. best) spark plug to use for stock AP1. Is the same also true for AP2 (MY08)?
2. If I were to use spark plugs other than NGK PFR7G-11S (e.g. say Denso Iridium), is there any downside or might the car not run properly?
3. If I use Denso iridium does this mean that the service gap when brand new will almost certainly not be the factory recommended (i.e. same as NGK PFR7G-11S)?
4. I just found out the previous owner of my car installed Denso iridium spark plugs with heat rating 6. But NGK PFR7G-11S is heat rating 7. Is there any downside to continung to use the heat rating 6 spark plugs?
Many thanks!
1. I note NGK PFR7G-11S is the correct (i.e. best) spark plug to use for stock AP1. Is the same also true for AP2 (MY08)?
2. If I were to use spark plugs other than NGK PFR7G-11S (e.g. say Denso Iridium), is there any downside or might the car not run properly?
3. If I use Denso iridium does this mean that the service gap when brand new will almost certainly not be the factory recommended (i.e. same as NGK PFR7G-11S)?
4. I just found out the previous owner of my car installed Denso iridium spark plugs with heat rating 6. But NGK PFR7G-11S is heat rating 7. Is there any downside to continung to use the heat rating 6 spark plugs?
Many thanks!
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Joined: Mar 2015
Posts: 12
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Sorry one more question. What is the recommended interval for changing spark plugs? FYI, my car is driven two days a week, 6.5 years old now and is about 20,000 miles.
Honda manual seems to say spark plugs should be changed every 7 years. But surely this can't be right??
Honda manual seems to say spark plugs should be changed every 7 years. But surely this can't be right??
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Joined: Apr 2015
Posts: 16
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Hey guys, first post since i joined here recently. I picked up a 2005 s2000, one owner with 32k miles on her. I want to change all fluids and also take a look at the spark plugs. Now for the intervals of changing, the car is 10 years old, even though the car only has 32k miles on it, should i still check them and maybe get a new set of plugs for it? The car runs great and does not burn any oil whatsoever. Thanks guys
Joined: Jun 2010
Posts: 5,539
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From: McKinney, TX
Hey guys, first post since i joined here recently. I picked up a 2005 s2000, one owner with 32k miles on her. I want to change all fluids and also take a look at the spark plugs. Now for the intervals of changing, the car is 10 years old, even though the car only has 32k miles on it, should i still check them and maybe get a new set of plugs for it? The car runs great and does not burn any oil whatsoever. Thanks guys
