Spark Plug Questions

New here. Got a few questions on spark plugs.

My current plugs have ~92K miles and need replacement fast (original plugs). I purchased some Bosch Platinum x2 (read that the 5VZ-FE required 2 grounds). They are said to last ~100k miles which would be well worth the extra $$$ but I hear the 5VZ-FE eats spark plugs for breakfast. Any thoughts or comments on these plugs would by great (I can still return them).

Im about to go ahead and change the plugs but dont have any of my old tools (all have disappeared since my high school years... probably dispersed between my friends/families/neighbors/etc...). Anyone have a list of the tools and dimensions required for the gen 1 tacoma V6? Im sure theres a thread with this info but couldnt locate it.

Thanks!

 

Awesome, thank! What is the part # for those plugs? Any recommendations on some performance plugs. Im looking for some platinum plugs that run up to 100k miles while offering great gas milage as well.

 

Nice thanks! AdvanceAuto said I needed to gap my plugs at .044. What would you recomend? Currently have aftermarket exhaust and a K&N box filter so I was thinking I would need just a bit smaller gap (~.040ish).

 

The 3.4 is a "companion cylinder" ignition system or better known as waste spark. The way the plugs fire is in a loop where the spark (current) flows out through one plug and back through the other. One piston is one compression and the other on exhaust so that is the "waste side". These types of systems are picky about plug design but work very well. Here is why.

Platinum plugs are used in modern ignition systems to reduce wear on the tip that occurs during the firing event. On a VERY micro level, every time the spark jumps it erodes a little metal from the tip. In a traditional set up where the spark travels in one direction the platinum can be put in to reduce wear. On a waste spark system you would need platinum on BOTH sides or the wear will be uneven causing drive-ability issues very soon. Ford in the early days had vehicles shipped where they had two part numbers for each engine at the factory. One side had platinum on the tip and the other had platinum on the ground tab and were installed as required. The service (replacement) plug was a double platinum part number.

I will NEVER use a fine wire plug (that tiny center electrode) in ANY vehicle with a waste spark ignition system. You are almost GUARANTEED a rough idle or misfire condition in short order. I do not care if it is a Toyota, GM, Ford, Mitsu or whatever, they do not perform correctly in these systems. I agree wholeheartedly with those that tell you to use the correct Denso or even NGK plug.

The issue about reducing plug gap for performance is misunderstood by many IMHO. The amount of turbulence in a combustion chamber helps set the gap requirements because it can increase the Kv (kilovolts) required to fire. You can actually see the ion trail bend like a lightning bolt if you set up a spark-plug to fire in the shop and blow compressed air across the electrodes. It is really cool to see and the results of the bend can be measured by higher KV on an ignition scope. In an engine, this can cause the spark to be "blown out" causing ignition breakdown and misfires typically under heavy load at the upper RPM range. It takes some SERIOUS modifications to require a change in gap from original design on most engine. If you had a super charger running a high boost, that would be a reason to reduce gap. Other than that, stick with OE design plugs and gap for best overall performance.

Sorry, you asked for the time and I built you a watch, but I thought this was an important topic. I have fixed many vehicles of the years that just were stuffed with plugs that were flat WRONG for the engine.

 

To the OP: Stick with the oem Denso's or NGK's non-platinum/iridium and replace every 30k miles. Those are the best plugs for the 5vz. They're cheap and are easy to find. As for tools, you just need basic wrench/extension and spark plug socket 5/8's i think, nothing to it. If you are thinking of getting better mpg/hp with platinum or iridiums, it will be minimal at best. And like what the previous poster said, you really won't benefit with platinums because of the ignition system that the 5vz has (waste spark). It grounds or fires on one side during compression, then fires again on the other electrode when it's on the exhaust stroke.

 

So im doing the same thing on my next oil change. but I was wondering how bad is it that I havnt changed the plugs once since Iv owned the truck and I really doubt the original owner did it either. Mine has about 108k on it

 

Is it going to complicate swapping the plugs?

 

I have a feeling that aint going to be pretty

 

This is perfect, thanks! I used to work on cars years ago and it seems the complications have really become... well complicated. Its a whole new learning curve.

@ 98taco, I looked for the IIRC,

$50 Denso PK16TR11 / 3289

Denso PK16TR11 and fond some online, however when I went to the store (Advanced Auto) they had the part but it only had a single ground (???). In fact, the only dual ground plug I can find between Advance and AutoZone was the Bosch. Im ordering offline for the correct plugs but thought I would share that with you (I hate ordering offline).