Question about recurring Ignition Coil problem

Hi Guys....
I have a question regarding the above situation.. Three weeks ago I had to have the #2 and #3 Coil and Plug replaced at my favorite repair shop here in town.. About 3 days ago, the exact same symptoms occurred again (started out fine, went about 1/2 mile down the road and then felt like it was running on 2 cylinders with obvious major loss of power........barely making it back home..).. It was just towed a moment ago to the shop, so I'm not for sure yet that this is a repeat of the same thing, but the symptoms are identical..
My question for you guys today is what could be causing this? Anything come to mind right off the bat when thinking of causation of this problem..?? I've got about 150,000 miles on this truck and it's been running excellent since I bought it in December of 2010.........that is, until the first event happened..
Just to let you guys know, I have very little knowledge of engines so not for sure if I could answer any specific questions you might have regarding that.. Today I'm just mainly wondering if a cause for this happening jumps out at you..
Thanks in advance for any info you might have...!

 

I have no idea about CEL codes.. I do know that the engine light was on AND blinking.. As I said above, do not know much about engines, just looking for some general ideas of what might be causing this.. Any rough ideas? When I hear from the mechanic and his diagnosis, will let you guys know what he said.. I'm just worried this BS will continue since it appears to be the same thing as before..
Thanks again for all responses back...!

 

Thanks for that Sean266.. I was unable to take it to Auto Zone to check things out, as I barely made it back to the house.. Had it towed to the shop from here today so it's kind of a done deal at this point.. If this keeps up, I believe I need to purchase an Ultragauge....!

 

In my experience, a flashing CEL has indicated a misfire. Having the codes read can narrow it down to which cylinders are afflicted. Normally fitting it with a new one takes care of it. These newer engines are vastly more complex and as a result, more difficult to troubleshoot. The best that I could speculate on is that you have another coil bad, the one that was replaced was defective, you may have a dying spark plug or a wire(s) relating to ignition that are defective.

 

Just wanted to follow up on the ongoing situation with my Tundra over here, but first wanted to thank all of you that have responded back.. Much appreciated..!
So I got a call earlier from the repair shop and it WAS another ignition coil that went out.. This time it was #1.. So, I've now replaced #1 through 3.. I asked the guy on the phone if he asked the mechanic what might be causing this, and why it's happening all at once.. He said that "that's just what happens at some point, and that eventually you'll have to replace them all." Maybe he's thinking I should just replace them all, but that's not an option at this time.. So, now I'll always be wondering when the next one will be going out.. Just curious.......do you guys agree with what he said? I have no idea either way as I'm the nonMechanical pawn in this game right now.. Wondering your take on all this.. As usual, thanks for all responses back..!

 

I'm not as familiar with the 4.7L and how the coils are set up, but in my dealings they're a sealed unit. They are subject to lots of potential vibration and heat cycles. Some will last longer than others. I've replaced ones at 100K miles where others have lasted over 300K and beyond the life of the rest of the vehicle. I would be surprised if at some point you had to replace them all, but it doesn't strike me as unreasonable to have one or maybe more stop working within specifications at some point on a truck with over 150K on it. The ones I had to replace were less than $100 ea. Considering what they're subject to, that's okay in my book.

 

Make sure you are dealing with a mechanic you can trust since you have no way to verify their diagnosis.

 

You can verify the issue by buying a decent code reader. It will point you in the right direction as to which coil is acting up. Move the coil and drive it awhile and if you get a misfire at the relocated coil you'll know it's the coil and not the wire or plug.

I wouldn't call the ignition coils going out reoccurring. Tremendously inconvenient and untimely but you realize they were probably installed at the same time

 

Having the same issue. 2004 Tundra in October this year had the misfiring and flashing check engine light. Replaced coil packs and spark plugs. 2 weeks ago same issue and they replaced the coil packs again and now this morning it happened again. Don’t know if something else could be happening to make it misfire and harm the Colin packs.

 

What brand coils are they using? Lots of hit and miss quality out there. Denso units are the best and usually about $50 each. Super easy to replace yourself if you're willing.

 

I’m going to check to find out what brand they used. Im sure it’s some from Napa

 

Denso is your friend

 

10mm socket or wrench and one plastic clip. So easy a caveman could do it. My apologies to any cavemen who are offended by this comment. replacing 8 of them with quality Denso units all at once would set one back roughly $400, or less than one tow and diagnostic at a reputable mechanic, certainly much less than the repairs there.

 

For reference, I'm still rocking my originals installed at the factory in 1999 with 265k+ miles on them. They can last a long time. They can also develop cracks in the tube / sleeve portion.

 

A lot of time it's not actually the coil that fails but the rubber boot and spring that makes contact with the spark plug. The rubber boot cracks or splits causing the misfire. It's cheap to replace the boots and springs when replacing the spark plugs when they are due to be changed. Most every shop will replace the coil that comes with a new boot and spring.

 

@skyclad. A good code reader is your friend. You can get them at any parts store. The misfire code will tell you which cylinder if you google it. Only buy Denso could and electronic parts for Toyotas. Rock auto is the best place to them. They have a discount code for our group