I went to a Jiffy Lube only once, but I've gone to Valvoline Instant Oil Change many times. What made me stop going there and strictly change my own oil from that point forward?
One time I brought in my own oil. My car at the time took 2.98 quarts (so does my current car). Says so in the manual plus if you put 3 quarts in, the dipstick reads full. So, I mean, it takes 3 quarts! lol But after I handed over the 3 quarts, the tech goes and looks up my oil capacity in their system and comes back to tell me I need 4 quarts. I told him he was wrong and I can prove it with my manual, but he can prove it just by putting the 3 quarts in and checking it. So he did. That was the last time I got my oil changed by anyone but me because that incident made me wonder if they'd been putting 4 quarts in it all the other times I got an oil change there using their oil. Also made me wonder if others might do the same. 1 quart over actually capacity is quite a lot when you consider capacity is only 3 quarts.
TBH, I'm tired of changing oil in my car. It's not easy getting to the oil filter and is a messy job as a result. I hate doing it anymore.
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Another story, this time Jiffy Lube - happened to a co-worker but I saw it with my own eyes. The girl went to a JL 40 miles out of town, then drove home. Oil light came on and she stopped into work becuse home was another 15 or so miles, bawling her eyes out. I happened to be on break and went to check if I could see a problem. The problem was immediately evident. Stream of oil on the ground coming from under the car. Looked under and there was no oil pan drain plug. My guess is they put the drain plug in but very loosely and it fell out sometime in that 40 mile drive. She said she noticed the oil light come on a couple miles before she stopped into work. So she got lucky. Far as I remember her car was fine after she got a new plug and filled the oil, but it could have been catasrophic.
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One of the problems is this: I had a friend that got a job at VIOC in another state right after he moved there and he had no mechanic training, certification or experience. It was little more than minimum wage at that time, plus bouses for upsells for which they had quotas to meet. I mean, they'll hire anyone with a pulse. Not that it matters much because the stuff they do is simple, but I think that's part of the problem. But no certified mechanic's gonna work at these types of places - it's a low wage job and instant oil change workers aren't so much mechanics as they are upsell agents. It's all about the upsell, no money in the oil change.
I know it's really convenient but it's really best to just stay away from these places of you care at all about your car.