3rd Gen Tacoma Spark Plug Replacement.

imo, that is too small a sample size especially for a MPG variance that small (5-10% of the EPA mpg estimate) Right foot, environment, city/hwy ratio, gas mix/quality; all factors. Temps are dropping, expect to have to put a few more psi in the tires to maintain the same cold tire pressure (Rolling resistance) in the mornings.

 

FL truck. Just did tune up last week, Forgot to mention, after finishing forgot to plug throttle body sensor back after finishing. Obviously underpowered and lit up like a Christmas tree. After checking and reconnecting tips to throttle body it drove normally and chk engine lights disappeared, but noticed lower mpg. Give it time to relearn?
Thanks for response

 

115000 at tome of tune up.

 

so i just followed this write up and did the plugs at 66k on my 2017 sport manual.
one thing to note is the intake support bar closer to the firewall holds the clutch line, so i just removed the two bolts mounting the bar to the engine, and let it hang in place.
2 plugs on the passenger side and 1 on the driver side were finger tight, literally no ratchet on the extrnsion required. these 3 plugs had a gas smelling oily residue on the threads by the sealing washer and around the washer itself, and were slightly black at the electrode. the other 3 were the opposite, looking reddish/whitish with no black anywhere.
happily, once all were replaced, my test drive yielded a shockingly quiter engine. i swear there is a rattling sound that seemingly creeped up on me that is now gone. no codes, no mil light. same mileage as always.

 

Are you the original owner?

 

This time around I did the plugs at 100k and cylinder 3 was loose. I know that I torqued all of them to spec.

 

yes, and i have done all the maintenance myself, and i never thought to check the plugs. always was just "man these motors are noisy at idle".
why do you ask?

 

I ask because if you are the second owner the original owner may have changed the plugs and not torqued them correctly.

 

ahh, understood.
i was pretty shocked. seems like some people find loose ones even when they had previously torqued them themselves. i hope i don't wind up in that category.

 

On my second spark plug change some of mine were loose as well. I torqued them all to spec. I went right over spec this time. We will see what happens at 180k

 

Would be interesting to see which torque wrenches people are using. Brand, size, and age.

 

I usually go a tad over spec, because spec has a factor of safety built in to it. unless a lot of oil/lube is involved. Then I’m right at spec. And I always store my torque wrenches at 0.

edit: a tad over meaning set wrench to spec and give a lil squeak extra or a “nother click and tug” past the initial click.

 

Typically there’s a +/- 5% tolerance window on torque specs.

 

I have a snap on electric torque wrench and a Matco click type. Snappy is 5-7 years old and Matco is 10 years old, but was calibrated in 2018. This time I used both of them just to see.

I will probably not go 100k this time and instead check and replace at the factory 60k interval.

 

Did you put anything on the threads?

 

25yr old HF clicker. A friend checked the calibration one time in there and said that it was good if coming up on the torque properly.

Almost 10yr old digital torque adapter. That thing has done heroes work with low torque fasteners in aluminum threads.

 

Yes, very little anti seize on the threads.

I know the manufacturer says not to. I’ve been doing that for the past 11 years now and never ever had a problem. We’ve had some cars in the shop where plugs were seized or extremely tight in there, it’s one of the reasons I keep on doing it. But that’s also on Mercedes, could be an engine or manufacture thing.

There are many debates out there for and against putting anti seize on spark plugs.

 

Are you upping the tq value because of the anti seize? Trying to figure out why a properly tq'd plug would back out.

 

Going a bit past the torque spec. I don’t know why it happened. Never had it happen before.

 

No antisieze used here. First torque wrench was a 2 year old husky. The second was a 3 week old husky