That tells me the heads are fully prepped (valves adjusted and spark plugs installed) before the heads get married to the block.
Scott
Spark Plugs: NGK or Denso?
- Thread starter Marrk
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Scott
the toyota fj was built like that
Is there a sticker under the hood which states what spark plug to use?
Have you pulled one of the existing plugs to see exactly what it is?
Have you pulled one of the existing plugs to see exactly what it is?
So odd. BMW FSM makes a big stink about not mixing spark plug brands. I guess in a factory they have complete control over what goes in
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On my car the 3UZ-FE a sign that the dealer worked on the vehicle is 7 plugs are one kind and 1 is different by the dipstick. Dealers routinely avoid the plug near the dipstick or so urban legend goes
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I’d be curious if true because watching a Toyota Highlander YouTube rear bank is more difficult may be a case where dealer only did one bank of a transverse V6. For the factory do do things like that seems less likely
OP - just be very persnickety when torquing those down, and heed the factory-updated torque specs. These engines are seeing lots of cases of plugs backing out and trashing the threads.
New spec is 20 ft-lb WITH anti-seize, which is a lot tighter than the original spec I've seen around of 13 ft-lb (sometimes wet sometimes dry).
The picture below was obtained online, and depicts the online and PDF service manuals floating about on the left which contain the original torque spec, and a printout from this person's local Honda dealer REVISED on the paper on the right.
New spec is 20 ft-lb WITH anti-seize, which is a lot tighter than the original spec I've seen around of 13 ft-lb (sometimes wet sometimes dry).
The picture below was obtained online, and depicts the online and PDF service manuals floating about on the left which contain the original torque spec, and a printout from this person's local Honda dealer REVISED on the paper on the right.
If these are wasted-spark ignition systems, it's possible the factory specs double-precious-metal plugs for one bank only. In wasted-spark systems, the spark plugs are fired in pairs. Current flows from the centre electrode to the ground electrode of one spark plug, and from the ground electrode to the centre electrode of the other plug.
The precious-metal ground electrode is only required on one plug of each pair (3 out of 6 in a V6).
I would guess a single-precious-metal plug costs the factory slightly less than a double.
Multiply that by three plugs per V6 x millions of engines, and it makes sense.
First say, I don't think you can go wrong with either. Some years ago, when I did my 3.0L V6 Accord, Denso was OE (all) but I replaced with NGK. I'm just partial to NGK plugs, always had good results. Unless price significantly less for Denso, 'I' would use NGK. I purchased mine from AAP because with online discount code at time (25%) it was best price and same day pick up. I cross shopped RA but with shipping they were more. Might be different now.
My 91 Honda CRX Si came from the factory (Suzuka, Japan) with Champion spark plugs installed (RC9YCN4). I was shocked when I did the first service on it and pulled a Champion out of the cylinder head. Ran perfectly fine, but I've run NGKs in it ever since.
Denso is 25% owned by Toyota, with their parts widely used throughout their product line. They don't make junk.
Back in my consumer car repair days, one of my jobs was as a Master Tech at a Toyota dealer. The official explanation for NGK in one cylinder head, and Denso in the other (on V configuration engines) was so Toyota who used both NGK and Denso as suppliers, wouldn't favor one 'brand' over the other. Of course replacing with all one brand when it came time for replacement, was fine.
I could see that - Japanese business culture includes maintaining good relationships with competing suppliers.
Fascinating. Was this practice done on other engines?
Our 2006 TSX 4 banger came with 2 NGK and 2 Denso plugs from the factory. Of course that's Honda, not Toyota.
If it's a waste spark ignition with three double ended coils - one side initiates fire from GND to Centre while both will oscillate. The Denso TT - or similar - work with low misfire counts in this application. There was a lot of this with DLI before COP became de rigueur .
Seen it in the 90's on Ford 4 bangers, GM V6 and Subaru, just to name a few
- Arco
To be clear, Honda recommends both DENSO and NGK for my car, and I am confident in both manufacturers, having used both over the years. The reason I posed the question is that, for the last several years, DENSO has been priced 30% higher at my retail sources and online.
I went with the NGK. I'll see how they look when they get here. I'm sure they'll be fine.
I went with the NGK. I'll see how they look when they get here. I'm sure they'll be fine.
