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Battling Mechanics

I have an '09 Jetta. This is the first time I am owning, rather than leasing, a car. I’m at about 50k miles at 40k VW’s manual and the dealership service center recommends a servicing that includes spark plug changing and checking various systems. I called a local mechanic, that was highly rated on this site, who told me that he had never heard of changing spark plugs so soon and I shouldn’t do it until more like 80k miles.

So my question is do I follow what’s in the manual or place my car in the care of this highly rated local mechanic and follow his guidance?

Also, how vital is it to have them do checks on the various systems if I am not having any issues and no lights have come on the dash?


Zach in St Paul

Replace the plugs now. Even though the original plugs might have a great deal of useful life, with time they seize in the head. When they seize removing them severely damages the head.

I agree with Rod on this. Besides, failure to follow the manufacturer’s recommended maintenance could invalidate your warranty should you need it.

The only time I disregard the owners manual is to do something more often than required. If it says 40k, do 40k. Plugs are fairly cheap.

You do not wait till you have a cavity to begin brushing your teeth, right ? You perform the recomended routine maintainence to KEEP them working their optimum, even though there’s nothing wrong with them today.

Same with checking mechanical systems BEFORE a malfunction costs you massive dollars more than if you catch it early.

I’d follow the maitenance schedule in the glove box. If you void the warranty and something goes wrong in the warranty period, you pay. And you tend to get a long, trouble-free life if you follow the schedule.

Many new cars no longer have a maintenance schedule in the Owners Manual… Now you get the advise to take the car back to the dealership every 6 months and THEY will determine what maintenance you need…If you want a printed Maintenance Schedule, you have to ask the Dealership for one as it’s a separate document.

No car I have ever owned has EVER been back to the dealership once the warranty has expired.

I think it is prudent to simply follow the recommended intervals from the owner’s manual. After all they should know, they designed and built the car.

My strategy on plugs is always to buy the standard garden variety – you know, the kind that cost $2-$3 each, and change them out around every 30K. I always apply some anti-sieze at the same time I do the install, and never had a problem with the threads sticking later. Sticking threads is something you definitely do not want, so that’s another reason to keep the plugs changed out regularly. It has always worked well for me anyway. The plugs can get dirty and oil fouled, but the real reason they need changing is that the gap increases each thousand miles, and eventually the gap gets so wide it can cause misfiring and detonation, both of which are no good.

Most modern Ford vehicles go 100,000 miles before a plug change is required. They use platinum plugs and an advanced ignition system. The past problems with stripped threads and broken plugs have been addressed and are no longer an issue…But as others have said, each manufacturer sets their own maintenance schedule.

I guess the change-out strategy depends on how difficult it is. If you do it yourself I mean. On my early 90’s Corolla, one I get the plugs and the tools in front of the car, if it takes 15 minutes to change them out I’d be surprised. I could have changed out half on them in the time to read this thread! But if changing the plugs is a time consuming chore, then putting in the more expensive longer life versions probably makes sense. Especially in newer cars where the stripped thread problem apparently has been solved.

And it’s almost always best to follow the manufacturer’s recommendations on routine maintenance, when there is any doubt.