Coil Packs - Replace as needed or on schedule?

[MrCWineMan]

Okay, I've been digging through all the info I can find and I can't come up with a good answer on the 200 series best practice. In short, should I preemptily swap coil packs at around 100k when I do plugs, or should I sit on it until they throw codes and replace them as they fail? I had a local mechanic suggest replacing all of them with the plugs at 100k, and I had another mechanic suggest the opposite. So what is the iH8Mud opinion here?

 

[bloc]

I don't see many people on here doing coils at all, even as a result of failure, and despite that we don't see many reports of ignition related diminished power, mileage, or driving dynamics.

IMO as-needed is the best practice here, and even then you are unlikely to end up doing any.

Your local mechanic could be used to working on other brands of vehicles that don't put as much emphasis on the initial quality of their parts.

 

[04UZJ100]

270k on coils on my 100 and 220k on my 2UZ 4R. All original.

 

[bloc]

270k on coils on my 100 and 220k on my 2UZ 4R. All original.

Yeah I was gonna say 190k on my 200's coils with no apparent issues. Still getting the same mileage I did at 105k, which is a decent indicator of coil efficiency.

 

[grinchy]

I put in new coils and plugs at 245000, along with a new maf. Very noticeable difference, but since I did at same time as plugs and maf couldn’t tell you which was more critical. My plugs still had tips, but they were visually worn.
Personally I think it was the coils, no evidence though.

I also did a/f and o2 sensors a couple weeks prior, and that made less difference initially, though with the new plugs and coils, maf and sensors the truck is very responsive and getting about 10% -15% better mileage.

 

[TimCFJ40]

I'd make sure your plugs get replaced every 100k miles, then replace the coils as needed with Genuine OEM Coils.

My short story is this:
At 260k miles, while on a long (2.5 weeks) trip out west, I got some stumbling and stuttering in low rpms, high speed (Think 60 mph in 6th gear, right before it kicks down to 5th). No codes initially, then it threw a "Misfire cylinder 1" code. Replaced coil on cylinder 1 with one from NAPA (only one available on a Saturday 100 miles from the nearest dealer) That coil lasted about 1000 miles before the issue returned. Replaced with another from Advanced Auto parts and made it home on that one.

Once Home, I replaced all the plugs, which I am pretty certain were the original plugs (Tips worn off), and replaced the coil with an OEM Toyota coil. No issues for the past year since. I keep the used but functional Advanced Auto coil in the truck as a just in case.

Planning to head on a few several thousand mile trips this summer and not worried. The coils are easy to replace, and when one goes you're not stranded, especially if you carry a spare. They're also fairly easy to find in a pinch as they cross over to the Tundra.

Note, I would avoid replacing yours pre-emptively unless you're just really worried about it and you are ok spending ~$600+ on OEM Parts. Definitely avoid the Amazon/E-bay cheapies. I suspect they're similar to the parts store ones that I blew up on my trip before getting everything sorted out at home.