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2007 Toyota Camry - why did the gap grow on my plugs?

Dear 2007 Toyota Camry 2.4L engine owner,

After only 30,000 miles on my Iridium DENSO SK20R11 plugs, the gap grew from a .043 in. to a whopping .073 in. on all four plugs! This increase of gap seems a lot from the previous spark plugs that have been in my 2007 Toyota Camry 2.4L engine. The engine has 146,000. miles on it. Any ideas why the gap grew so much on these Iridium plugs?

John R. Davis

I can think of a few things.

  1. You didn’t gap them when you installed them.
  2. you mis gapped them when you installed them.
  3. You bought the used and refurbished ones off ebay.
  4. You bought the half priced counterfeit ones from Hong Kong with free shipping off ebay.
1 Like


Thank you for commenting on my question. Fake plugs seems a real possibility for the plugs I bought. I’m going to dig a little further into these plugs, as I don’t remember if I bought them from Amazon or eBay. I was wondering if I could ship my plugs to you
so you could determine if they are fake or not. I’d be glad to pay you for your opinion. Your suggestions were very much appreciated.

John R. Davis

Why have you posted a link to a web site ? Any parts house might be able to tell if the plugs or fake. Besides what difference does it make now because you are not going to get a refund.

Well, I was commenting on the person’s suggestions on what to look for if I bought fake plugs. His link was helpful. Your suggestion to take these plugs to a parts house seems helpful, too. I guess, using your suggestion, Autozone, NAPA, or O’Reilly might
be able to check out these plugs. Right? I’m not looking for a refund, but I am trying to figure out why these DENSO plug’s gap grew so wide, so fast.

The gap grew that much after only 30Kmiles? It’s probably some sort of plug defect. Other possibilities

  • there’s something wrong with the circuit in the ignition system which determines how much voltage should go to the spark plugs. as the gaps widen (normally) that circuit increases the voltage to accommodate a wider gap. maybe that circuit thinks it always needs max voltage for some reason. If this were the case I’d expect your coils would be suspect too, near failing, at this point.

  • that circuit may also bumps the voltage on cold starts, so could be the car thinks the coolant is always cold.

Sheesh, who woulda thought they’d be selling fake plugs too now. I guess another reason to avoid Ebay and Amazon for auto parts. Yeah NAPA is my go to or the dealer or the Rock.