Spark Plug Replacement

[garagedude]

2002 TOYOTA AVALON SPARK PLUG REPLACEMENT


This information is FYI. The car manual says that the car comes with IRIDIUM Spark Plugs that need changing at 120,000 miles. My car never missed a beat – but at 124,000 I decided to change the plugs. I removed the factory NGK IRIDIUM IFR6A 11 plugs from the engine – all where extremely clean, with some sign of wear on the center electrode. They probably would have lasted a lot longer, however I was glad I pulled them as two were a challenge to loosen up.
I searched out the internet and found:
Original plug NGK IRIDIUM IFR6A 11 no longer available – new part is IFR6T 11
Also listed is the DENSO IK20 (5304) These were about two dollars more (about ten dollars each) – so I bought DENSO plugs.
The front bank is easy – I used a 5/8 inch spark plug wrench with appropriate extenders to unscrew and pull the plugs out of their holes. For replacement – I used a regular long 5/8 inch socket as if you use the spark plug wrench – I couldn’t pull out the socket due to the rubber form in the socket and the extenders would just disconnect leaving the socket attached to the plug.
The rear bank – I reached around from the right side of the engine and pulled loose the rubber hose for the PCV valve(SQUEEZE THE CLAMP WITH OUR FINGERS) . Then remove the PVC valve from the left end of the engine. I also removed two ground wires bolted onto the plate on the end of the intake manifold, plus I unbolted the small assembly connected to the intake manifold plate. These two steps give ample access to removing the rear plugs from the left side and the right side.
While fearing this effort – it turned out to be straight forward and relatively easy. I have put 5,000 miles on these new DENSO plugs – car seems to have more power and I am happy with the change. Total cost was about $60 plus cost of new PCV valve. For those that fall for the dealer saying the plugs need changing at 60k or 90k ---- I DON’T THINK SO!!!!!!

[Mike Murrell]

Yep. Let plugs sit in a motor for too long and you'll have a hard time getting them out and run the risk of stripping the threads in the head.

All the more reason to ignore these ridiculous extended interval plans.

[gold4runner]

[quote=garagedude;774198]2002 TOYOTA AVALON SPARK PLUG REPLACEMENT

So you are saying the factory 100K change interval appears to be ok based on your car and your observations of the plugs.

[garagedude]

The 2002 TOYOTA AVALON operators guide says change plugs at 120K. Toyota usually knows what they are talking about. The factory installed IRIDIUM plugs were perfect until I decided to replace them at 124k miles. The car is about six years old. The plugs were really clean, and so were the threads.
I had two that were a little testy - but mainly because they were in the back of the engine block on the passenger side, and getting leverage for loosening up the plugs was a little difficult. The front plugs unscrewed easily.
I do understand Mike Murrell's input - one doesn't want to strip the threads. If I had to do it again however, I would do it at 124k miles..... Your choice...

[benbeaux]

I changed the ones in our old '99 we had at 100k since the car was being sold to my brother-in-law. All came out easily & were replaced with the denso brand. They looked slightly worn & had light to medium grey color. I also added a small dab of anti seize to the threads of the replacements. I cleaned the pcv valve with throttle body cleaner & checked for the rattle.

A thorough cleaning of the throttle body & butterfly valve helped a lot. It also cured a sticky throttle that caused an intermittant jack rabbitish start. I used gumout jetspray throttle body cleaner for the front side & sea foam through a vacuum line behind the butterfly valve for the back end.

Now that I think about it, I forgot to clean the MAF.

[jake696]

I take my courier car (Corolla's and Matrix) Toyotas to 200K+ on those iridium plugs and they still look fine! We drive at mostly highway speeds (65-80 MPH) out here on the northern prairie with no trouble or loss of MPG's...

If I change them at all...it's because we sell the cars to employees and (students) people I know (at 250-300K) when we are done and like them to be serviced well and w/o issues in their new life.