Spark plug question

chry*bmb

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Here's the dilemma. My dad's 2004 Toyo 4Runner threw a p0306 misfire cyl#6

it's a big problem with this generation, it's not uncommon for it to be a head gasket. The damn dealer told my dad it was an ignition coil and quoted him, of course, hundreds of dollars. So Bernie and I did it for him. I mean, so damn easy. Changed coil and got new spark plugs. Of course code came back after clearing the code.

My question, really just a clarification, because my memory is shot, the spark plugs we took out were of two diff manufacturers. Denso's were on one side while NGK's were on the other. Wouldn't they burn at different temperatures? Just doesn't make sense why the hell it even had two diff ones to begin with. The stats all make sense, but still...
 

Flyn

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Someone got lazy and had plugs lying around?

Could it be a 2nd coil also failed? Examine all of them to look for signs of damage or oil. If you find oil around one, the plug threads may have stripped. That happened to me with my Cobra and I had to install an insert to fix the threads.
 

ilikemtb999

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I had a misfire code being thrown randomly on start up but intermittently. Did the typical fixes without it going away. Turned out it was a knock sensor failure.
 

chry*bmb

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Checked them. No signs. Even tried switching. Bank 2, the one that contains cyl #6 was pulled. No visible signs of damage. Was sent to machine shop. They pressure checked and resurfaced. No warpage either. Looks really goos. So it's the head gasket. That we can see.
 

chry*bmb

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See? Cyl 6 being leaked with coolant
 

chry*bmb

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I was just shocked to see two diff sets of plugs on this truck!! So did it come from Toyo that way? Or did Dealer fuck with it? But iirc, I thought plugs burn at diff temps?
 

chry*bmb

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Bernie doing the hard work. I dont want to mix shit up. I started, but then got
 

chry*bmb

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Here's just a small sample of ppl with pretty much same problem. HG issue, same bank...

 

1quick

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it could be different brands but the exact same heat range, still some brands of plugs suck in some applications that happen to be the same heat range as the normal plugs, ive ran into this with my boat it hates ngk plugs but they are the same spec as the delco's that came in it
 

Flyn

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Unfortunately, being a 2004, you have no warranty recourse. Back when my Cobra had issues with the half shafts, Chicago Mike and I gathered a lot of evidence showing there was an issue with them with many of the cars. We both publicized the data and got Ford to replace our half shafts. We were both under warranty which helped a lot. Ford eventually decided the half shaft replacement was too expensive and came up with a couple cheap "fixes" that did not work and (IMO) waited for the warranties to run out.
 

nytebyte

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Unfortunately, being a 2004, you have no warranty recourse. Back when my Cobra had issues with the half shafts, Chicago Mike and I gathered a lot of evidence showing there was an issue with them with many of the cars. We both publicized the data and got Ford to replace our half shafts. We were both under warranty which helped a lot. Ford eventually decided the half shaft replacement was too expensive and came up with a couple cheap "fixes" that did not work and (IMO) waited for the warranties to run out.
I remember that whole fiasco. It was a metallurgy issue if I recall and I was lucky that Ford replaced mine.

No problems since.
 

chry*bmb

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The whole thing is crazy!! I did find this out...

Not a big deal, each bank was made in a different location then sent to another for assembly. Yes, V6's of this age have 3 Denso and 3 NGK plugs from the factory

If you were to just Google the problem on this exact year, make model and put HG leak? You'd see. Toyo apparently fixed it a couple years later, but yeah @Flyin High Again , no way will we get any compensation. Lol I guess they were even talking recall too? Just glad it's found and will be fixed. Just sucks Toyo never stepped up. They are still pretty damn good. No complaints on all the Toyo's I've had.
 

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