Spark plug change interval on Toyota

My (relatively) new Toyota recommends spark plug change at 120,000 miles. Anybody feel that this is too long? I usually go less than 50k for this service item. Comments? Thanks folks! Rocketman

Toyota uses iridium spark plugs and yes they will last for that long. I see cars on a daily basis with over 100k on the original plugs.

I just changed the plugs on my Corolla, 100K miles, the old ones looked great. I had trouble finding the iridium plugs at the Mcparts stores and got them from the dealer at a reasonable price. Easy removal and install. No change in performance, I could have probably gone for a lot more miles on the original plugs.

I know they can go that long, and I know the reasons, but I prefer to change them at 60K.

Sparkplugs aren’t so expensive that preventative maintenance should be stretched as far as possible. To me it’s kind of analogous to putting gas in the tank. It’s better to do it when the tank reaches half empty than wait for the “fill” light to illuminate.

By the way, it would have been nice to know the model of Toyota you bought, and the engine if there was an option.

It depends how accessible the spark plugs are. Some can be a real bear to get at.

As long as the Check Engine light doesn’t come on indicating a cylinder misfire, I’d service the spark plugs at the interval Toyota recommends.

Tester

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My 2003 Avalon (V6) I had them changed at 100k and regretted it afterward. The old ones looked like new. And it was NOT cheap–the labor is quite high due to the perverse engine put in sidewise. The rear bank of plugs are awful to get at.

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Sorry mountainbike, it’s a 2013 Toyota Yaris, 1.5 engine, 5 speed. My kids are both in college so I mostly drive by myself so I got a gas sipper, she gets 45 mpg all the time. I believe that I’ll follow your lead and do the plugs at 60k. Rocketman

I worry more about the plugs getting seized in the cylinder head. I change them at 50-60K miles.

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yup

If it’s a Ford, the plugs will either blow out or break during removal . . .

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Aww c’mon @db4690, Ford 3 valve mod-motors are bad about breaking plugs but it IS possible to get them out without breakage. I found a couple of YouTube videos showing a clean removal with an impact wrench. That’s how I removed mine at 52,000 and they all came out in one piece. I did, however make SURE I had a car to drive in case I needed to order the Lisle tool to extract the pieces.

I agree with early plug changes. I get a little nervous leaving them in for 120,000 miles. More from a “seized steel sparkplug in an aluminum head issue” than a wear issue.

@Mustangman I have a couple of special tools for those 3 valve tritons

One helps to prevent breakage in the first place. The other removes them, if they do break

I don’t use the impact. However, once I remove all the coils and boots, I spray a bunch of penetrant in there, and really let it soak in, and work its way down the threads. Then I work on another car, while the penetrant does its thing. Then I use an air nozzle and blow out the excess penetrant and the dirt. It always manages to find its way down there

Then I work each plug back and forth slowly It’s manageable

Under no circumstances would I attempt a spark plug replacement if I didn’t have the lisle tool in my possession. Because I’ve done a few replacements already, and the occasional plug does break, even if you’re careful

I’ve seen a bunch of the videos, by the way

In all honesty, I prefer the 3 valve mile long plugs to the 2 valve plugs, which tend to blow out. I’d much rather use the lisle tool to remove a plug, versus installing a timesert

The factory plugs have an anti-seize plating on them, they will not stick. They will come out easily at 120k or longer. You can change them earlier if you want, but it will be a waste of money.

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On my '05 Camry I changed them at 100K miles/9 years and had no issues. It was running fine and the emission results were perfect, the old plugs looked just fine. Only one of the clips on the connector broke and some electric tape fixed that.

@galant exact same thing happened to me when I replaced my plugs

Yaris plugs should be fairly simple to remove, so I’d be inclined to at least remove them and do a visual inspection at 60K. Maybe even every 30K. If they look ok, the gaps are still within spec, dab a little anti-seize on the threads and pop them back in. You can catch problems before they occur with a visual inspection of the working ends, like one cylinder going rich or lean, plugs working themselves loose, etc. On my Corolla anyway it takes at most 15 minutes to remove and install all the plugs. Probably not even that.

On vehicles where the plenum needs to come off to get to the plugs, if I’m going to that much trouble, the plugs and plenum gasket are getting replaced

No matter how great they look

And then there are other designs, where I would never EVER do plugs without making sure I also had a new wire set on hand

There are even cases, where you replace plugs and wires one month. then for some reason you need to inspect the plugs the next month. And those month old wires break, even though you were using the proper tools, the right method for removing the wires, etc.

Just curious about the terminology dB. Is the plenum that rubber boot thing which routes incoming engine air from the air filter ass’y to the throttle body?

I believe it is the intake Plenum/Manifold. My 3.3 Dodge Caravan was a PITA to change the rear 3 and there are stories online how to do it. My current Mazda CX-9 would need the plugs changed in a year or two and the manual calls to remove the plenum, change the gasket and so on.

The plenum is the upper intake manifold, on many cars it has to be removed to access the plugs. The eletrical connector at the coils seems to last about 5 years before they break on removal.

Ok, I think I understand, on my Corolla the plenum is the big complicated shape aluminum passageway thing from the throttle body to the cylinder head. Yes, if that has to be removed, I’d want to do everything I could while it was removed in order to not have to remove it again. It looks very heavy and awkward to handle.