Well, whan I had to break down and quick-lube my truck a couple of weeks ago, they must've been suspicious of me for some reason... Guy shows me a sample of every fluid, tells me it's fine (even the brake fluid, which looks like bad diner coffee and PEGS a dipstrip stone cold purple; I gotta change that soon)...
Air filter is about 10,000 miles old, tells me it looks brand new...
Coolant is nearly two years old... remember when we used to change green stuff every two years no matter what?
-edit- please read the rest of this post in it's entirety before replying, giving me time to put my asbestos undies on (I know someone is going to flame me over this)-
Here's what we do...
at EVERY oil change, we ASK if it's over 3,500 since it was last done... if the answer is YES, then we ASK if they WANT to add an oil cleaner...
at 10,000 miles, we ASK a customer if he WANTS to change his air filter (not tell him he NEEDS it, ask if he WANTS it)and show them the old one...
at 15,000 miles, on a gas engine, we'll ASK if they WANT to add a fuel injector cleaner...
at 30,000 miles, we ASK if they WANT to power purge the fuel injectors, and FLUSH the transmission...
at 80,000 miles we ASK if they WANT to change the coolant (ever seen Dex-Cool at 100,000 miles? The stuff looks like chocolate milk)...
here's the deal...
Automotive air filters only trap stuff down to about 50 microns. K&N and other high performance filters aren't called "squirrel traps" for nothing (anything smaller than a squirrel will pass through). The more junk that builds up in a filter, the harder the engine has to work. On top of that, the fibers in a dirty filter are actually sucked apart by manifold vacuum, spreading the space between them open, reducing the efficiency of the filter. I'll slap a 12,000 mile filter on the counter and watch the loose stuff fall out. Doesn't do much for the stuff trapped in the fibers, though. Blowing through it with compressed air, you say? What do you think a high-pressure blast of air does to the paper fibers?
Oil, even the best synthetics, build up varnishes over a period of time. Clean it out periodically, or have sticky lifters and more importantly on belt driven camshafts, hydraulic belt tensioners. I get about three engines a year that were trashed because the belt tensioner stuck, and the belt jumped, and a piston smacked a valve. Spend $20 on cleaner a year, or junk a $3,000 engine.
Transmission fluid is not a pan drop and filter on may models anymore. I can think of at least one domestic and one import manufacturer, where the only time you change the filter (strainer) is when you have the cases apart. What about the garbage that accumulates in a TCC? A spill-n-fill leaves it in there.
Spend $75-100 on a flush every 50,000 or spend $1300. replacing a torque convertor.
Brake fluid absorbs water, lowering boiling point, and leading to brake fade. Plus, in an ABS system, you have aluminum, steel and copper parts. Add in moisture from the fluid, plus the rubber dust from the cups in the master cylinder, and you have an abrasive "battery" corroding your brake parts from the inside out. Flush it for $80 or put in a $1300. ABS unit.
Coolant has an additive package of anti-corrosives, lubricants, and anti-foam ingredients. They are designed to react catalytically with the different metals in your cooling system to keep it from becoming a low voltage battery, and eating your parts up from the inside out. These wear out over time and need to be replaced. Filtering the ethylene glycol (which no, does NOT wear out) isn't going to replace these. Hence, the need to flush a cooling system. Try this; take a DVOM and ground the common lead, put the probe lead in your coolant. Depending on the state of electrolysis in your coolant, you will get a voltage from .5 to around 2.0 volts... the higher the voltage, the more depleted your additives are... Flush it for $80. or replace a plugged radiator and eroded hoses for $400.
Injectors: even the best fuels will leave deposits inside the injector body, and nozzles. The more heat they're exposed to for a longer period of time, the heavier these deposits will be. Camshaft overlap (reversion), and PCV gasses flowing through an engine, coat the inside of the manifold with a slurry of carbon, varnish and oily deposits. Compare this to charcoal lighter fluid... you pour it on coals and the coals absorb it, right? Well, this stuff does the same thing to VOC's. What it does, and why you need to clean it periodically, is as it absorbs VOC's, it makes the engine run lean... when it saturates, and the VOC's evaporate back out, it throws the engine rich. Now, GM says you don't have to purge Mul-Tech injectors. I disagree. Varnish builds up on the shuttle, and in the fuel ports, just as it does in pintle valve injectors. Flush them for $70 or replace a clogged injector for $300.
Now... that being said, most fleets I deal with (GE Capital, Donlen, PHH, Wheels Inc) won't flush a system. Figure they lease say, 1,000 cars a year. If the loose one or two transmissions, they're still money ahead.
What if that one or two transmissions happens to be the car you're driving? You're out of business for a few days. If you're a sales rep, you make exactly $0 while the car is down...
You suppose he is off looking for a new job? Probably the VP of Jiffy Lube by now..
