What happens when a shop uses the wrong plugs!

I have 2002 taco double cab. I bought it new and love the truck. Sunday morning the check engine light lit and the truck started to shutter badly. I purchased plugs and wires. Before I got chance to replace, I had to accelerate hard and then the light blinked a few times. Well in its life time I have replaced tires brakes O2 sensors the normal stuff. It has 240,000 miles on it. Because of time issues I have brought it to various shops, I'm very slow with repairing stuff. Anyway I started changing plugs about 8pm. I thought I'd do half and continue this morning. I was horrified when I got the first plug out, it was a one electrode auto lite. Oh in Sept I had replaced a catalytic converter, in yet another shop- only indicator was cel and code reader. My question is could there be damage caused by these plugs, which I do not remember which shop or when they were last replaced. I don't know what to do. The shops I've used have been the dealership ( til warranty ran out) and chains, as I don't know a good mechanic- dad always did the car work. I didn't use shop for brakes and oil changes. I realize that you can't trust a shop now even with that sticker that tells you what plugs to use the wrong ones were inserted, possibly my truck engine is ruined?

 

It's not ruined from running a single ground plug. Everything I've read says that the single ground plugs don't last as long, but aren't damaging. The reason from using double ground plugs is because each plug fires twice as often as "normal" because there's only three coils (assuming a 6 cylinder engine).

 

Omg! Burn it.

 

I agree with the first sentence, no harm done to the motor, running those plugs for a short time ...
but I don't agree with the second sentence. My 2.7 4-cylinder also 'double fires', but calls for single-ground plugs. Must be another reason for the double-ground plugs on 3.4 motors.

 

Is there only two coil packs on that engine?

 

Yes, just 2, mounted on the front of the motor. One is labelled 1-4, the other labelled 3-2

I carry 2 spares at all times.

 

Thanks guys I continued on my quest to get job done. But then I found thiswhat now. Am I dealership bound? Is it fixable? That explains the cyl 6 code

 

I think you can put that back together. I did something similar on my wife's Nissan van (I really hate working on that damn van).

 

What engine have you go, Agoldensmile?

Either way, if it doesn't go back together Rock Auto has the Denso replacment for about $55. Don't know what the dealer wants for it, though.

 

Just get a new coil..... or put the boot back on.... or go to you comfort zone, the mechanic., nothing wrong with that if you're uncomfortable.

 

I have the six cylinder. I put the boot back together and the truck is much much better, my concern was the coat of oil, which I guess wasn't evident in the pic. It was only one plug that had oil but that boot sure was covered. My comfort zone is not a mechanic, I just need encouragement and need, enjoy and benefit from other persons experience. Thanks.
Oh I checked out rock auto- thanks I saw a few things that may be helpful to me.

 

A little bit of oil outside of the spark plug is ok and expected. Glad the truck is running great! Good job.

 

bit late but heres my $.02 as an auto tech/machinist.

honestly going with the wrong plug does absolutely nothing. so long as it's the appropriate heat range for your truck youre fine. and even if it's wrong it wont do much. only other way to mess it up is to put one that's literally too fat to fit in the heads which is not going to happen.

however, using a cheap autolite in an import is just plain wrong. make sure you get the original NGK spark plugs which were either copper or nickel........ if instead original was platinum, go with iridium instead. electrodes don't really matter, they would be a gimmick if it wasn't for the fact that they slightly guarantee a spark.

you can buy the boots separately if you want to change them go ahead. they should be changed with the wires every 80-100k miles. lot's of coil-on-plugs have that option. this is very common. no biggie.

oil on the other hand is a bad sign. there should be no oil in your ignition system at all whatsoever. older distributor engines ran off the cams where oil would sometimes seep through. our coil-on-plug trucks have no intended interaction with anything that involves oil. the most likely possibility was that the spark plugs were not tightened all the way and oil came in from the chamber up passed the plug and into the boot. but that's another problem. oil coming from your chambers is a sign of bad rings, pistons, or head gasket. hopefully the head isn't cracked. but thats extremely unlikely. it may be time to overhaul the top end of the engine. but after 240k miles, your baby has earned it!

what your doing is a simple tuneup you can do yourself. just make sure you follow proper procedures. buy a haynes book, theyre very helpful. the link i gave is the correct book for your truck. don't need to look any further

but for the harder work you don't want to do. you can always go to the dealership, though they're expensive. there are also certified toyota shops around, don't discount them. if you wan't to find a good all around garage, speak with NAPA auto parts or the local machine shops. i did a general search for machine shops around new jersey and wow there are a lot of them! im just going to say find a certified toyota mechanic/garage in your area. if you find several, do your research on them and check reviews. always go with the best.

 

Funny thing go in almost any autoparts dealer ask for spark plugs for your year 3.4 most times you end up with a regular plug.

That is just what happens to be in there system so that is what you get.

Then most shops have the helper doing tune ups while mechanics do timing belts etc.

I just buy my plugs at my Toyota Dealer I don`t think they are that expensive.

 

Single electrode plugs, as long as they are the proper heat range and size/depth, will not hurt your engine in any way shape or form. The only way a spark plug will cause damage to your engine is if its to hot causing an extreme lean condition(not real common on a lower performance automotive 4stroke), or the plug is to long and makes physical contact with the piston. As to the oil on the boot of the plug it is most likely from a leaky valve cover gasket or oring around the spark plug tube, not from piston rings or anything serious like that. You would have to have one serious oil burning issue which would be most likely noticeable In the exhaust, AND the plug would have to be loose in order for oil to come out of the combustion chamber to get on the boot.

 

Thank you so much! I am considering doing the valve cover gaskets as my research indicates that it is most likely that. Of course it seems like I should have done plugs at same time, who knew. Lol. I guess the auto shop guy I had knew Toyotas as he only offered the double electrode NGK plugs. Is it possible that the plugs can be relevant to gas mileage? I had gotten about 20 mpg in earlier years but the past three my gas mileage decreased , I filled up after replacing plugs and the gas mileage seems to be better- closer to my 20 mpg, however that's only based on one tankful.

 

So it only makes sence that the cat takes a beeting if the wrong plugs are used. I bought my truck from a guy that was convinced auto lights were the only plug to run. The tail pipe had black soot at the end. The wrong plugs make you milage suck.

If you pushing a gallon thru every 12 miles that extra fuel has to go some ware? I think it gets a partial burn in the cat. I changed the plugs in mine, cleaned the tip, but I still have that stinky cat smell even after a year. I'm sure the wrong plugs were in mine for about a year. With the right plugs the tail pipe is clean.

I will be changing the cat when I put the trd headers in.

The other thing to watch for is power steering fluid!!! Only use ATF

 

I had new cat put in in Sept, so I'm hoping I am good, there. Don't know how long I had wrong plugs in.

 

Straight from Toyota.

 

Some sexy info you got there. :-D