Jiffy Lube = total incompetants. I have never been to one where the people knew the SLIGHTEST thing about cars. They just hire them and teach them, like a monkey or dog, to do one task repetitively over and over and over until it becomes routine. Then they STILL mess things up.
They broke my dad's windshield, and only the fact that the regional manager was there saved his ass.
When I had my old Volvo 240 (whose engine was in pristine shape) they told me I had 1) piston slap 2) bad valves 3) knocking 4) an oil leak and 5) a bad clutch.
Each and every one of those statements was a lie, and my first visit became my last. The guy behind the desk hated the mechanics, and told me to say no to every procedure other than the oil change - engine flush, hose replacement, oil additive, lube every possible part they can toss grease onto, engine wash, etc.
Man, NEVER trust those places. Someone once said of Best Buy here on the board "I wouldn't let them install an air freshener." Well, I wouldn't let Jiffy Lube change a dollar, let alone change my oil.