Long Islander

I have a 2018 E400 wagon with 27k miles and soon it will be 5 years old. The maintenance schedule says to replace spark plugs after 5 years, but I've never replaced spark plugs after only 27,000 miles. Should I skip it? It seems between the cost of the spark plugs and the labor cost, this will be quite costly, and it's not something I plan to attempt myself. What do you guys think?

DFWdude

Skip it.

chassis

Don't skip it, follow the manual. With 5,000 miles per year on average, this car hasn't cost you much to operate. $600-$700 for a spark plug change is worth it, unless you DIY which means it would be less than half that amount.

tyo

$600-$700??? Is this for real?

I would never pay such price considering amount of work. I mean that it takes max 30min to do so.

Am I wrong?

cetialpha5

It's a variant of the M276 engine which typically requires the removal of the intake manifold in order to get at spark plugs as it's a 60 degree V6 instead of a typical 90 degree V6 where it's much easier to access the spark plugs. There are ways to do it on the regular 3.5L M276 without taking off the intake, but not sure if that still works on the 3.0L turbo that's in the 2018 E400. And yes, that's probably what the dealer would charge. Could probably get a lower quote at an indy shop.. Standard is 5 years because they don't want the plugs to end up rusting in, say you waited for 10+ years and the plugs snapped while taking them out or were rusted in and they wouldn't come out. Still it's probably a small risk so OP could probably go a few years longer. Don't forget Mercedes uses a multi spark system, the plugs can fire up to 4-5 times per cycle instead of regular plugs in the old days that only did 1 per cycle.

Long Islander

Thanks guys. I'll call my local independent shop which services all my cars and see what he charges.