99 E320 Change spark plugs
 

The dealer quoted $320 to change the spark plugs. What's the trick here? I know there are 12 of them, but is it especially difficult to do? I have lots of sockets and extensions and the like. But looking at it, it doesn't seem terribly more difficult than some other spark plug jobs I've done in the past.

Car has 82k miles. Is changing them necessary now?

Believe it or not, I think that is not a bad price for a dealer. I've heard number from $400-500 for the M113 spark plug change.

No, it is not really any different than changing the spark plugs on any other engine. The main difference, is that there are 12 of them and the plugs are typically $10 each or more.

Yes, it is necessary to change them now if they have not been changed. While the mileage interval is every 100k miles, Mercedes also recommends not going more than 5 years without changing them due to the fact that they may start to become difficult to get out of the head if they sit in place for much longer than 5 years. If it's a 99, then it has been 7 years, I would change them.

I think I'll let the dealer do it. Wrestling with 12 of them and getting them backed out of aluminum, mm, not really appealing.

Thanks for the advice.