2 years ago I got the p0300, p0301, p0302..................

So I replace all of the plugs & coil packs and it has ran great until 2 weeks ago, Got a p0302, replaced coil 2 w/ one of my "good" takeoffs from 2 years ago.

Today, got codes on all of the other cylinders (but not #2).

I bought all OEM coils and plugs 2 years ago when I replaced. Is there something I should be looking for that would cause these failures after only 2 years? I find it hard to believe that all 6 coils would fail on their own after 2 years.

Any Ideas?

yes the first thing i would check is my plug's spark gap. Too large of a gap will make the coils work harder and cause pre mature failure.

I too would suspect plugs or oil on the plugs.

OEM plugs are the right ones to use. If you do the gap is not adjustable ... gnd bar does not have flexibility/pliability to be adjusted.

Salim

I used OEM plugs when I swapped them out. I don't remember messing with the gap or not. I went with OEM coils ($500+) so I wouldn't be replacing them any time soon. Since they burned out anyhow, I think I will just buy cheap ones off of Amazon.

Is there a way to test the coil packs with a multimeter?

did you torque the plugs to spec or torqued them enough to feel the crush rings flatten when you swapped them out? If they vibrated loose and backed out, it can also cause coil pack failure.

I would also inspect the wireing harnesses running to the coil's without that heat protective wrap around the wires, they can melt...with the heat of the engine block and give the engine the fritz 😎

No, they were tight

2 thoughts:

1. Lexus explicitly states not to adjust the gap on the Denso iridium plugs when you install them (don't know why). You are using iridium plugs?

2. When you get multiple misfire codes, frequently only one coil is bad. Fixing the bad coil gets rid of the codes on the other cylinders.

Good luck!

Reason is because iridium plugs are fragile. The tip will break or you will at least have scratched/chipped the tip.

I erased and ran codes a couple of times and got p0304 consistently--my lucky day!, So I swapped in one of my "good" takeoffs from 2 years ago and no problems for 2 days so far. I really cant believe that I lost 2 --2 year old coils in 2 weeks. I'm pretty much expecting more to go out.

I'm also getting engine noise (fluctuates with rpm) on my am radio. Could that point to any issues that could be burning up my coils?

You might have a poor ground somewhere. Where are the critical grounding points on the engine?

There is one very important ground strap on the back of the intake manifold....Sorry no pictures, but it is very important.

Let's just say, I can definitely confirm that this ground is very important. I have first hand experience!
I believe this is the one you are referring to:

They use this blanket statement because most people dont know what they are doing. I always check/adjust mine and they are usually out of spec . You cant touch the electrode or it will shatter.......................................................ps... I replaced a coil pack last year with a new one from ebay which was like $14 shipped to me. Yea i was skeptical but its still working fine. Fortunately I have an extra car to use while waiting on parts.

That's the one...thanks