How to: Installing 3rd gen spark plugs
- Thread starter zcruiser
- Start date
TheOGConCon
New member
Anyone know why our rigs came with 3 NGK plugs and 3 Denso plugs from the factory? Because if they came that way from the factory... when we replace our spark plugs, provided there's a good reason, wouldn't we benefit from replicating the 3 and 3, as opposed to buying 6 NGK or 6 Denso?
TheDurk
Elite Member
The popular wisdom is that it was simply a supply/production decision. Toyota wanted two suppliers for its plugs, and produced the heads in two different factories, so the logical least-cost logistical solution was to have each supplier provide plugs to one factory. I have never heard an argument that there was any performance ingredient to the way this was done, other than idle speculation. Dealers have used one brand, Denso, as replacements on both sides, since Day 1. This is also logical, as Denso is a partially-owned subsidiary of Toyota, and NGK is not. I have used NGK exclusively since 1999 in my rig, and I am perfectly happy with the results.
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TheOGConCon
New member
Good to know. Thanks for the well detailed answer!
zcruiser
Senior Member
Well, made a trip out to WV to help with flood relief, 800 mile round trip. I noticed some stuttering on acceleration (at high rpm) so looks like I need to do this again.
I checked, and I've put 60K on these plugs since this write-up. Seems a little soon, maybe I can just re-gap. Pics to come...
I checked, and I've put 60K on these plugs since this write-up. Seems a little soon, maybe I can just re-gap. Pics to come...
Please do! I would like to know if this addressed the stutter.
I should add, also check the TPS...
Sent from my SM-N900W8 using Tapatalk
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zcruiser
Senior Member
So after 60K miles, my plugs look like the ones I removed when I started this thread (well maybe not quite as bad).
New vs 60K:
Seems like higher than expected, IMO. The gap is approx .054". I didn't have time to change all the plugs so I pulled the one that was easiest to access just to have a look. I actually regapped the plug to .044" and put it back in for the time being.
Here are the ones I removed 60K ago (2009)... These had about 130K miles on them, original plugs (nasty)...
I suppose it is an option to regap them all to .044" and put them back in but I think they are going to wear more rapidly from this point on so it's not worth saving approx $25 on a set of new plugs... I'm not that cheap!
I do need to replace the valve cover seals also, but I think I'll hire that out to my neighbor the Subaru mechanic.
New vs 60K:
Seems like higher than expected, IMO. The gap is approx .054". I didn't have time to change all the plugs so I pulled the one that was easiest to access just to have a look. I actually regapped the plug to .044" and put it back in for the time being.
Here are the ones I removed 60K ago (2009)... These had about 130K miles on them, original plugs (nasty)...
I suppose it is an option to regap them all to .044" and put them back in but I think they are going to wear more rapidly from this point on so it's not worth saving approx $25 on a set of new plugs... I'm not that cheap!
I do need to replace the valve cover seals also, but I think I'll hire that out to my neighbor the Subaru mechanic.
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zcruiser
Senior Member
Here are the plugs I just removed after 60K, and only because I was getting stuttering at take-off as well as high RPMs right before the shift or if I was climbing a long grade (which was really annoying).
Pulled a trailer around today (though not heavily loaded) but I did punch it up an inclined on-ramp to the interstate and it performed nicely.
Still can't believe those plugs were giving me problems at 60K. :sigh:
Pulled a trailer around today (though not heavily loaded) but I did punch it up an inclined on-ramp to the interstate and it performed nicely.
Still can't believe those plugs were giving me problems at 60K. :sigh:
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Scramble
New member
I'm having the same problem, plugs keep shooting out of my block too. The dents in my hood are getting really annoying.
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zcruiser
Senior Member
This is about all you can do, just gotta work around it.
I did unclip the black diagnostic port and move it aside.
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zcruiser
Senior Member
That's really weird.
jeremyc74
Banned
I'm just going to add a couple of pics to the thread for good measure.
My truck started having a high RPM miss that I would notice most when it would downshift on the interstate with the cruise on. At first I was afraid the transmission was starting to slip, but after playing around with it with OD off I could tell it was just a miss.
So the truck had about 200k miles on it at the time, and I knew it hadn't been very well maintained. I already had a set of plugs and wires in the garage but hadn't had it home in months to be able to change them.
When I finally got back to FL and pulled the plugs, this is what I found. Original plugs with 200k miles on them. :toilet:
My truck started having a high RPM miss that I would notice most when it would downshift on the interstate with the cruise on. At first I was afraid the transmission was starting to slip, but after playing around with it with OD off I could tell it was just a miss.
So the truck had about 200k miles on it at the time, and I knew it hadn't been very well maintained. I already had a set of plugs and wires in the garage but hadn't had it home in months to be able to change them.
When I finally got back to FL and pulled the plugs, this is what I found. Original plugs with 200k miles on them. :toilet:
RedSled
New member
Here are the plugs I just removed after 60K, and only because I was getting stuttering at take-off as well as high RPMs right before the shift or if I was climbing a long grade (which was really annoying).
Pulled a trailer around today (though not heavily loaded) but I did punch it up an inclined on-ramp to the interstate and it performed nicely.
Still can't believe those plugs were giving me problems at 60K. :sigh:
From the pic. it looks like a pinkish color on 5 of the plugs, is that just pic. quality, or are you getting coolant in the cylinders?
zcruiser
Senior Member
I think they're really tan, plus I'm not running Toyo red...
zcruiser
Senior Member
Who reads the manual? :banana:
Scramble
New member
I did, a long time ago. So a lot of what I say from memory could be wrong. :wave:
CC Silver
New member
That is probably as accurate as it gets !
I did not move the diagnostic plug, but did move the lines out of the way. Lots of extensions for the plugs and some contorsions for the wires.
I did not use never sieze based on some of my reading and did use a rubber hose to get the plugs started.
The old were all Denso, so I believe they had been done before. All looked worn - the center post was tapered - but all looked good otherwise.
The only issue I had was figuring out how to get the coil to wiring harness connectors off - the tab is closest to the intake side of the motor on the top - push the tap on to release it and then the connector slides right off.
Now , I know...
Thanks for the help.
Britt
This is about all you can do, just gotta work around it.
I did unclip the black diagnostic port and move it
aside.
I did not move the diagnostic plug, but did move the lines out of the way. Lots of extensions for the plugs and some contorsions for the wires.
I did not use never sieze based on some of my reading and did use a rubber hose to get the plugs started.
The old were all Denso, so I believe they had been done before. All looked worn - the center post was tapered - but all looked good otherwise.
The only issue I had was figuring out how to get the coil to wiring harness connectors off - the tab is closest to the intake side of the motor on the top - push the tap on to release it and then the connector slides right off.
Now , I know...
Thanks for the help.
Britt
