Yet-to-be-named 2016 Fiesta SE

An honest mechanic is a rare as a youth pastor who doesn't molest kids.

Tensioner?

Should have been replaced anyways as part of the cost - so this is a "cleaning" I too - don't appreciate.

As a delivery driver, I've seen many "kits" - these tensioners come standard in them so I don't know why that they needed a part separately - the parts required, usually come as a required condition of the repair - not optional. (They do have bearings in them and so that makes for a limited lifetime - so it's required.)

It's also why I like forums - for the participants leave behind their experiences like footprints to follow a trail to get to the destination - only the journey is a small book they leave behind for others to read - we all get a little smarter about it because of that effort.

It's getting to a point that Warranty is not a thing anymore to be used to enforce the shop to stand by their work, it seems more like a passing notice that you should do this, but it doesn't always mean it's required. That is the part I don't get, definitely fishy.

And also good to know that many a shop - to save time and turnaround costs - will drop specific items from the list as long as the main repair is completed - only that small detail can put you back into that shop to have them fix all their work plus repair the part that caused the fail due to it not being repaired/replaced at that time because of lack of time to wait for it to arrive.

It's like a time bomb they put in your engine - they have it set to go off, only you're not sure exactly when it will happen, only that it will and do you want to be there when it does?

I think the mechanic FILLED up my oil. I noticed today that my fuel mileage seems to suck, so I set to try to figure out why. No drips on the driveway, so it's not an obvious leak. The exhaust smells a little rich, so I pulled the spark plugs and the two plugs closest to the coil pack were bathed in oil. I also saw that two of my plugs were eroded down to the insulation, so I re-gapped them just to get by until payday then I'll replace them. None of the spark elements looked wet, but they were definitely unevenly gapped for some reason. Checked the oil and it's definitely full; I may need to pull out a few ounces.
I'm not sure about getting into injectors with this car. I have no problem on an old mechanically injected diesel, but this electronic whiz bang is a different beast altogether. I usually run a high octane fuel and have never gotten so much as a knock, but is it worth it? Is there anything I should run through the tank to clean varnish out of the lines and injectors? Is that even a thing? I miss my old carbureted Beetle and Corolla. Anyways, after I sort out the plugs (wires were replaced 18k miles ago) how else could I improve the efficiency of this car? Yes, I still need shocks, struts, and an alignment, I'm sure the latter would definitely help. But as far as the motor goes, anything else? Thanks all.

Phil