YouTube channel Toyota Maintenance, loose sparkplugs

It appears to be quite common, I read it here on this forum too. I guess you could mess up the sparkplug coil from blow-by. How's is that possible on the assembly line to not have them torqued just right?
Is there a way to tell if you have loose spark plugs without removing cover and taking coils out...maybe a poor idle or jitter of sorts ?...BTW, the vehicle on YouTube channel Toyota Maintenance was a 17 Tacoma.

 

From the folks that have posted loose plugs, esp @Hank Heel , who had a really bad one, they had no performance issues:
https://www.tacomaworld.com/threads/psa-check-your-spark-plugs.673098/

My guess is that it is due to the long, spiral leak path. Even at idle, the amount of leakage is on the order of ring blow by. It is an accumulative thing.

Because of the reports, I checked mine and all were good except for the uneasy feel of the long, dry threads. I used antiseize and the low end of the torque range.

There is a chance that it might not have been the factory? Someone posted that plugs can back out from detonation. That is pretty speculative though.

 

It's not quite common at all. But, I have disdain for long spark plug intervals because of stuff like that this.

I would discourage someone with limited experience to retroque them simply because they could be loose.

Also if its a 16 or 17 just change the damn plugs while you're in there.

Usually blowby on plugs or oil causes misfires or coil pack failures, both can trigger a warning light.

 

No issues on mine. 50k

 

Sorry about this but I'm just curious what people are using for plugs? I'm about to change mine and I've see some Denso Iridium at rock auto but kind of want to just go with what was put in originally and stop by the dealer and pick 6 up. I don't want some knock offs.

 

I am only at 35k. LoL! The plugs looked great, as did those for others that I saw. One person was at 90k and found the right side plugs loose when doing the scheduled maint. Just some coloring on the insulator and coil pack. @Hank Heel was the extreme case so far.

To trigger a CEL, it has to hit a threshold. That small loss on each ignition will be small comparatively.


Also IMVHO, if folks have enough mechanical skill to deal with the left side plugs, I wouldn't worry about them checking their own. As these are long reach plugs, there are a lot more threads than typical. I would always recommend a torque wrench though. I'm a bolt snapper without one, so I just know better and use it religiously.

 

Factory double iridiums give me chub!

 

Agreed. It is the same on our high CR Mazda. No messing around. It depends what you like though. Denso, NGK, etc. Just cross reference the part number from the OM.

 

I only torque now, I used to torque by hand but the 4.0 V6 spark plugs on tacoma used to break with the slightest over torque on me, 2-3 times. So I started to torque every plug and haven't looked back.

The drivers side is the challenge, and I know of many DIY'ers that bugger up the 10mm threads on the coils or the brackets.

 

I hear you there. Esp with motorcycles and aluminum threads, I have yet to mess one up even on the Russian PoS when using a torque wrench.


Good info on the drivers side. I suppose it has to be said to start all fasteners by hand.

 

Mine is a 17 Tacoma but I only have 10000 miles...i think I will inspect them just to be sure...this stuff should not happen!

 

Anything can happen, you should see the stuff that happens on other makes, like ford's eco boost. You have little to worry about.

13ft lbs for these specific plugs. A dab of anti seize on each plug would go a long way as well.

 

I have complete confidence on any Toyota products but I think quality control should be raised.

 

No one knows the root cause of this yet. It is just starting to get traction since the 3rd Gens are just getting to the mileage of plug replacements.

Of course, if this is somehow due to the engine tune, then yeah, it is still a quality issue.

On the silver lining side, at least it is just plugs. A consumable item to start with.

 

The older Toyotas were far worse for this, tube seals, coil packs, headgaskets etc.

2nd gens have to change their plugs every 30k etc.

The quality is great now, you are just more exposed to the limited failures.

 

Oh, you are not trashing OG Toyota quality in the 3rd Gen section?









I still remember the secret engine swaps during the sludge crisis.

 

What happens on the ecoboost?

 

Gotcha. I've gotten a fuel pump from Rock Auto over a decade ago and it turned out fine but I think I'll just save the second guessing and get the ones in a Toyota box from the dealer. Here is the P/N.
9091901263

 

The only think I can remember was a small number of Focus had an incorrect head gasket, but was quickly issued a recall to take care of it.