Yikes! 15,000 miles between changes? I second what Beth said: That's ridiculous. Problems like these may be why Mercedes has done so poorly in the Consumer Reports reliability ratings -- particularly in the area of electrical.
I read through the other post, it sounds like the German government mandated the use of biodegradable insulation ... I can't see why you can fault Mercedes-Benz for that.
Keep in mind that we are talking about a 20 year old car here ... were we transported back to the days when this car was new, would we be holding 1970's vehicles to a similar standard? I think we'd be taking pride in all the Macgyvering done to keep it on the road so long.
Such comments show how much the quality of automobile manufacturers has improved in recent years. I find faulting spark plugs that only last 15000 miles to be quite amusing. Back in the REAL OLD days you would be lucky to get 15000 miles out of a set of spark plugs. I believe that the mandate to warrant ALL emissions related components for 85000 miles has led to a good bit of the difference. Combustion is so well controlled that the plugs aren't as likely to become fouled, and exhaust is monitored to flag when a problem occurs.
While I am not too knowledgeable in MBz maintenance, I do have several vehicles of similar vintage for which I perform maintenance. I too remember the old Bosch plugs with a platinum center electrode puck in the middle of the insulator ... those would qualify for "Made By Monkeys" classification in my book, but Bosch had another series of platinum center electrode plugs that look like other more conventional center electrodes, with the ground electrodes approaching the center electrode from the sides and with curved profiles to maximize the surface area over which spark may occur. These plugs truly last a very long time and perform well IME.
Final comment ... I would disagree that spark plugs cost the other poster $1000. That individual assumed that the $1000 part was bad without performing any diagnosis! Back in the days when spark plugs lasted 15000 miles, one of the first things to do when experiencing a misfire is to pull the spark plugs to "read" them. It seems common these days for people to "shotgun" a problem when there is plenty of information that can be gathered to make a more informed *diagnosis* ...
Yes, I know about those MGs. I had three or four friends who owned them. They needed constant tinkering. But the guys I knew who owned MGs liked to tinker. This was in Michigan, so there was plenty of rust. They were really great at cornering.
Perhaps since 1992 they've addressed the problem, in which case our monkey iteration is but an interesting historical diversion. On that point, the award for world-class wiring problems would probably go to older Jaguars. MGs, no longer imported into the States, had electrical issues in spades, along with a host of mechanical challenges. (I forgot to add, rust.) But they sure were cool cars. Fodder for future "Monkeys," no doubt...
I agree, Beth, it is surprising. 15,000 miles is not a lot. It makes you wonder at the decision-making behid this. Would a company know for quality -- and a high price for the quality -- risk the brand on cheap components? Could be the business-school mentality of focusing on cost cutting for the bottom line rather than driving the upper line higher.
If you can't trust the Mercedes brand to use top-of-the line parts, including wiring and electrode plugs, who can you trust? And to put the onus on the owner to either change out themselves or have the components changed regularly at 15,000 seems pretty onerous and shoddy especially considering the high pircetag on these vehicles.
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