Arthur I don't have the valve wrench found the picture at http://www.samstagsales.com/mercedes.htm
who has it for $49
Bob

Bob.
Many Thanks
Arthur

Wow!....$11 per spark plug ($132 for a set for my ML-320). I think there is a way to save some bucks. The working part of the spark plugs are good for 100,000 miles with quality unleaded fules and modern ignition systems. The reason the plugs should be changed after four years has nothing to do with the plug performance, but is to prevent corrosion from taking hold that could damage the heads if the plugs are removed after many years. Changing the plugs every four years breaks any corrosive bond that is forming before it gets too strong.
In a few months My ML-320 will be four years old and I will remove the spark plugs; wire brush the threads to remove any corrosion; inspect the gap; lightly coat the plug threads with a high temperature Anti-Seize compound, and re-install them. Since the Anti-Seize compound is also a lubricant, I will torque the plugs to the lower torque limit ( I think about 20N-m, or 15ft-lbs)

If I see any indication that the plugs are not in excellent condition I will install new ones, but this is not likely.

__________________
Tom H.

I wouldn't recommend doing all this work getting them out just to reinstall them. It's not that bad when you consider they were in there for 4 years or 100,000 miles.
You may be able to find a better price on the plugs than what I quoted.
I don't recommend using anti-sleaze on spark plug threads (although admittedly I don't recommend the use of anti-sleaze at all).
I agree that the purpose of the 4 year interval is to keep the plug from getting stuck to the head.
Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

Well, thanks to everyone I got them replaced.
They are hard to break loose.
As for the plugs cost got the OEM F8 DPER at $5.21 each for a total cost of $65
I made to remove the plug wires myself from an 5/8 combination wrench I heated and bent like the MB part, worked like a charm.
A few plugs broke cleanly at the porcelain when removing the boots and I had to fish the loose end out of the boot and vacuum our the plug hole (nothing was visible just playing it safe). Must be a result of less that strait out extraction of the metal jacket.
All in all my first try at repairs in a while and the first on a MB.
Total time involved 2hrs
Again thanks
Bob