Spark Plugs for 4th Gen V6 - Iridium or not?

4th gen V6 (2003-2009)

Apparently Iridium spark plugs are not the correct plugs for this vehicle. Even though the spark plug sites all spit out Iridium options when you enter vehicle information.

This guy has insanely good videos for Toyotas and is a certified tech at a dealership.

https://youtu.be/G5xFLj5baJw?si=xmGyAGhAfF-Pi1BD&t=751

 

As a retired ASE Master Tech and ASE Service Consultant, I like to still wrench at home on my friends vehicles from my American Legion and VFW and my neighborhood and their friends. Lots of them own Lexus and Toyota. I have used this "The Car Care Nut" videos for certified info on numerous occasions. It seems that Toyota recommends Platinum plugs instead of Iridium plugs in some of the models and years for some reason and I always tell my customers to stick to what Toyota recommends. I save my customers money by recommending Rock Auto and I also get a discount at RA on top of the lower prices. I don't make money on the parts, just the labor.

 

Agreed with @OR VietVet. You can trust The Car Care Nut. Yes he's a youtuber and you should take most of the info found there with a grain of salt but TCCN has been vetted, is a previous Toyota Master Mechanic and now with his own shop, just doesn't BS you with useless information.

If the V6 is calling for Platinum plugs from Toyota and TCCN is saying the same thing, that's what I would go with.

 

I would like to add something else to this spark plug discussion. As my signature says, I am a big fan of maintenance and I tend to replace parts and fluids before they are worn out. The 4.0 1GR-FE engine has no spark plug wires. They have ignition coils on top of the plugs. When you do the iridium plugs at 100k miles or the 3rd go round of platinum plugs, every 30k miles, replace the ignition coils that you have to take off anyway. Use, IMO, Denso coils and be happy. If you don't, I can guarantee you that the resulting eventual misfire, will not take place in your driveway. You can plan on the coils cost ahead of time and the labor is there anyway. Good clean spark, from coils and plugs, makes for better fuel mileage and better power and a smoother idle.

Talking about smoother idle, clean the damn throttle bore sometimes, huh!

 

Also agree with this.

At the very least, inspect the coil packs for cracking on the tube part that extends into the spark plug hole. Any cracks and that should be a replacement. As noted, use only Denso coils or OEM, which also happen to be made by Denso. In fact any sensor that might ever need replaced on the engine should be Denso or OEM only. Also recommend NGK spark plugs.

 

Thanks.

Toyota uses NGK and DENSO plugs at the factory. In fact, my 4Runner came with 3 Denso and 3 NGK plugs installed. It's common.

Not sure who makes the OEM coils.

From the NGK site. You can see they claim Iridium plugs are compatible. Interesting they would say this, even though you can see OEM plugs listed too which aren't Iridium.

 

OEM coils are made by Denso. Most sensors on the engine are made by Denso, including the starter. Not sure about the alternator but I would assume Denso there as well.

A mix of Denso plugs on one side and NGK on the other side, indicates those are the original spark plugs still installed from the factory Replace all with NGK Plats. They list the Irids as fitting because they do fit and they do work but will not function as well as the Plats will. The engine was designed to work best with the Plats.

 

Recommended and what you can substitute is a conundrum. If it came with the 30k miles platinum plugs, I would stick with it but I don't think the 100+k miles iridium plugs will cause a problem. I am also a big fan of using OE sensors and mostly everywhere else on the vehicle or a part from who manufactures the part for Toyota. The aftermarket is full of look alike crap that still takes the same labor time but then that time gets repeated because of poor quality parts. Also have to look out for counterfeit parts. Seen and heard of a bunch of those at Amazon.

 

Yeah, try to avoid Amazon when buying most replacement parts, just because of all the counterfeits that come from there.

Rockauto.com is my main go to for replacement parts and always have Denso listed.
partsuoq.com out of Dubai is great for OEM parts, Just check shipping before you pay as that sometimes is a factor but not always.
For US based online Toyota parts dealers, I mainly use McGeorge Toyota - mcgeorgeparts.com

Find the part number you need and do some google searching to find the best prices.

 

I have used and liked Parts Geek too.

 

Went with the NGK Platinum and sent the Iridium back.

Glad I found that vid, because I read many forum posts where everyone went with Iridium for their V6 4th gen. I guess it must not cause much an issue though as I saw no follow-up posts about bad performance.

 

How many miles on the ignition coils and are you replacing them while they are off the plugs? IIRC, they are easily replaced on the 1GR-FE engines.

 

Is 200,000 miles with original plugs and coils a bad thing ?? It still runs, idles, and drives great...

 

You are living on borrowed time and when it does give you problems, it will not be in your driveway. No way you have the same pep that new components would bring. You have adapted to it over time. It has a spark but is a weaker spark and that will effect the catalytic converters in the long run. Spark plugs and ignition coils are part of a maintenance program for a reason.

 

The problem with replacing Ignition Coils on TOYOTAs is that they are expensive to get the OEM or OEM supplier ones. The coils rarely go bad because they are of such good quality. I would opt to not replace them.

 

My ‘07 just hit 250K miles. Decided to replace the coils as PM and ordered the set from 1A Auto. I have their LCAs and haven’t had any issues, and haven’t seen anything bad from people who have used their parts. I’ll post my experience with them here and will keep my OEM coils just in case.

They ship fast, that’s for sure. I ordered on 12/26 at 10:30PM and UPS just delivered the parts.



Boxes say “Made in China” which is unfortunate but not a dealbreaker for me.