Is a spark plug -- just a spark plug?

Your father is right and wrong.

No.

Yes.

Yes. The NGK specified for your car, IFR5T11 (replaces IFR5A11).

 

patrick always recommends spec plugs. good enough for me. i have no clue.

 

Iridium tipped is the design for Prius and one advantage is that Iridium the hardest metal known to mankind, you can use these plugs up to 150000 miles (120k recommended). They are easy to DIY in a Gen2 so I did it once at 135k miles and I hope to never do it again. If you go with a lesser plug, we do not have good feeling for life of plug. With iridium after 135k miles you can clearly see the shiny iridium nicely holding the gap whilst the surrounding iron is eroded/corroded. It is such a valuable and rare metal I cannot bring myself to discard the used ones. Holding for day we wise up and recycle rare materials.

 

Further, not all iridium spark plugs are equivalent. The correct plug, NGK IFR5T11, has an iridium tip at the center conductor. It also has a platinum tip at the ground electrode. The result of this yields a 120K mile service interval.

Lesser iridium spark plugs lack the platinum tip at the ground electrode which cuts the service life in half, if you are lucky.

You can buy this plug for < $7 each on amazon.com:

 

Three(3) different compositions:
1.) Copper. ... Old-school, works just fine, softest of the 3, lasts the shortest, most economical. Use these if you want to go cheap or if you will be replacing the car soon.
2.) Platinum. ... Second metal of choice, harder than copper, lasts probably as long as you will need, +/- $2-$3 more than copper per plug, most likely OEM. For my reasoning I just replaced mine using platinum at 162,000 miles. I'll probably put another 162,000 miles on these.
3,) Iridium. ... Third engineered metal; hardest, will last the longest but not give noticeably any better performance than platinum (My opinion). I recommend these if you're changing the first time under 75,000 miles. These are +/- $5 more than platinum per plug.

I just changed mine. I'm 98.6% sure this was the first time. You'll want two(2) different sockets; a 10mm and a 5/8 spark-plug socket. I watched two(2) YouTube vids to see how they do it. First vid were the "Pro-Guys". They remove the air-box. We're talking a half'an'hour unnecessary work. The second vid was a "shade-tree mechanic" who just went in and swapped them out. NO big deal. Without removing the air-box you would be happier using a spinner-ratchet. This is negated however, if you experience what I did where the factory is not aware of the "tight is good ... tighter is not any better" theory. It seemed like Gadzooki put my plugs in at the factory. He didn't use and "anti-seize" either. You DO WANT anti-seize compound ($2 small tube). I used some very creative language while taking the OEM plugs out. The 4th coil doesn't come off as easily as the first 3. Using 2 flat-head screwdrivers you need to pop off the plug connector. If you're nice and careful it slides off easily enough and goes back on easily if you are careful and pay attention. NO big deal.

As per My recommendation when doing any general maintenance ... CHECK and/or REPLACE the air-filter. I also recommend getting parts from RockAuto ... NO ... I don't work for them but it's well worth the $$$ savings ... unless you don't care.

Also as per usual ... I changed the oil after the plugs. For Me I like to go +/- 5,000 miles between changes. I suggest that you just stop in any given good oil-change place and ask them to check the color and viscosity of your oil to see if you really need to change it. I could possible go another 2,000 clicks on the oil I had but I made a "W-T-F decision" and did it now.

Anyway ... That's this story.

 

I am using a new spark plug from Pulstar.

They are plasma core iridium.

 

At least as important as the creative language is, if that's the situation, use extreme gentleness.

It's not necessarily so much that they didn't know the right torque at the factory: the threads in the cylinder head are aluminum, and the ones on the plug aren't, and they can get very very friendly with each other over 120,000 miles with lots of heat.

Once you get it starting to turn, keep paying attention until it's all the way out; don't let your guard down. Any time you notice a feeling of binding coming out anticlockwise, stop and give it a little fractional turn clockwise again, then resume. You might do a bunch of that back-and-forthing. It does get easier as the plug comes out more.

You want the plug threads to come out, and leave their aluminum friends behind in the cylinder head to hold the new plugs. If that doesn't happen, the simple spark plug project turns into a much more advanced project.

 

I took my OEM iridiums out at about 135k miles, and turning them it was like fighting a big fish all the way back to the boat. Pt and Iridium are so rare I feel bad not recycling the old plugs.

 

I guess it's the same approach. Now and then you give the fish a little run back away from the boat, then pull again.

Maybe I'm just making that up. I haven't fished since I was like 8.

 

And a torque wrench to tighten the new plugs ain't a bad idea either. If your old plugs came out easily then I just put the new (OE brand) plugs in to factory spec- 13 ft/lb. The coatings on modern spark plugs are much better than decades ago. Used to have problems all the time with changes at 60k. Now I see many at 100, 120, or even 150k that come out with no problems.

If they do come out hard, then I might consider getting a special thread chaser made for spark plug bores to clean up the threads in tbe head (google is your friend). A very small amount of antiseize (on the threads only) and torque to 11 ft/lb.

Posted via the PriusChat mobile app.

 

They are in there really tight. Toyota likes really tight.

 

NO There are many differences in construction and temperature ratings. I agree with trying to replace with the exact same plug if the old ones worked well.

In fact, for my old tractor, I needed to research what it originally came with and try to cross to modern numbering.

 

No No NO....must use the newest gimmick nuclear fusion powered laser teleported inductive capacitive phased plasma spark plug in the 40 watt range.......guaranteed to get at least an additional 0.001 mpg at the mere cost of 3 payments of $35 per plug. And if you buy 3 right now, the fourth is free, just pay handling.

 

Just like using water 0W20 oil gives you an extra inch per gallon of gas but reduces engine life by 20% ?

 

OEM plug & igniter for a G2.