Tuesday, September 14, 2010

The Myth of the Modern Tune-up

It used to be a little frustrating to me when customers came into my shop looking for a tune-up...  I ended up confusing them by telling them that they didn't need one, there wasn't really such thing, and they should only do one or two small services.  (This is also another reason why I'm not in the business any more, since it's not profitable to turn useless services away!)

The service schedule for my 1978 MGB calls for these things to be done roughly every 6 months (Spring and Fall used to be the standards...)

  • Change engine oil and filter
  • Change air filter element(s)
  • Change spark plugs, ignition points and condensor
  • Set ignition point gap to .018" to achieve correct dwell angle
  • Inspect distributor cap, rotor and replace if any sign of carbon tracking.
  • Set static ignition timing to 6 degrees before top dead centre
  • Put a few drops of oil on distributor centrifugal advance weights and verify that they're free to move
  • Verify operation of vacuum advance unit, check that diaphragm doesn't leak
  • Set tappets to .008" with engine warm (And running if you're REALLY good)
  • Set choke mechanism and verify correct high idle
  • Set idle mixture and verify correct hot idle
  • Grease driveshaft u-joints
  • Check differential oil level
  • Check gearbox oil level
  • Grease outer tie-rod ends and steering rack
  • Oil trunnions
  • Check oil level in shocks

Now THAT'S a tune-up!  (And that's just from memory... I'm probably forgetting things...)

Not only do modern cars need virtually none of these adjustments and services, most cars that did are now over 30 years old, meaning that the mechanics who knew how to do them are all retired!

So what does MY car need?

You need to read your owner's manual, and ONLY your owner's manual, to know what services your car needs and when.  Most shops will always put a sticker on your windshield reminding you of a 3 month/5000 km (3000 mile) interval, but this may be WAY more than necessary.  Changing your oil more than required can't damage your car, you're not doing anything wrong, but you are wasting time and money.  My Golf, for example, calls for 16,000 km between changes.  I do it at 8000 anyway for my own sanity's sake, but that is the recommended interval.  Many cars also now have systems to monitor your oil change interval, and you can definitely rely on this.

When you take your car into a shop for an oil change and they start telling you about recommended services, you need to be educated so that you don't get anything you don't need.

Add-On Services

"Engine Flushes" - This one is a little annoying, and controversial.  The idea is that the shop adds a can of stuff to your engine that thins out and breaks down sludge that builds up in your engine (Before your oil change) and drains it out with your oil.  I've done these, and the oil comes out like water and black as anything.  Basically, if you're not sure of your car's oil change history or if you know you've gone WAY over your mileage at some point, it can't hurt.  You certainly don't need it more than once in a few years though!

Cooling System Flushes - you DO need to change your coolant at the interval recommended by your manufacturer.  Coolant becomes acidic over time and attacks aluminum components in particular, leading to all kinds of failures, from head gasket to water pump.

Transmission Flushes - Check your manual and ask your dealership.  There are a lot of different types of transmission fluid changes, ranging from full system flushes that don't change the filter to "dump and fills" that do change the filter but don't get all the fluid.  There are conspiracy theories to go along with each.

Brake Fluid Flushes - Same thing - your fluid should be changed whenever your system is opened (Caliper, wheel cylinder, hose or master cylinder replaced) or at the manufacturer's interval to avoid these very parts failing!

Fuel Injection Flush - A bit more controversial.  There are reasons to get this done, I'm sure, but my wife's Toyota has 285,000 km on it, has never had one, and runs perfectly according to my engine diagnostics and its latest E-test.  I wouldn't blow a lot of money on it unless you've replaced plugs, wires and filters and still have rough running with no check engine light.

So what am I getting at?

I guess my point is that a tune-up is a thing of the past.  RTFM (Read The F***ing Manual) ad go into any service as an EDUCATED CONSUMER and you'll be fine.


  1. Thanks for the kind comments on my blog :)

  2. wish i knew shit about cars. my girl would love me if i did

  3. uu thankies


  4. Following the normal service schedule laid out in my manual has never steered me wrong. 92,000 Miles on my 97 Ram Van and no extraordinary repairs due to maintenance.