99MBSport

I have a 99C280 sport and was wondering what plugs I should use and how bad are they to replace?? Should I do te wires also? Thanks in advance

Untertürkheim

How old are the wires? If you do replace the wires, be sure to use only the best, otherwise the car may be worse than with the old ones.

I like the Bosch Iridium +4, I have used them in many cars with excellent results.

guanabara

Use the original OEM spark plugs.
As far as wires go, the MB cars mostly use low voltage wires with the transformer right over the spark plugs.
That in most cases makes it totally unnecessary to replace them for the car lifetime, unless their insulation gets damaged or cracked.

Go on any reputable site that sells MB parts enter your car make model year and you will get the correct information.

sites I have used are:
partstrain.com
http://germanstar.net/c280m.htm

Looks like you are in for 12 spark plugs at a cost of about $8 each, plus mechanic costs, if not doing it yourself.

Untertürkheim

$8 each is far too expensive in the US for spark plugs, the Bosch Iridium +4 are never more than that, and they are the most expensive plugs.

guanabara

Actually the original type should cost around $4.50.

The iridiums cost about $12 ea and since the originals did such a good job until now , it is safer to use them or risk having problems with newer more expensive spark plugs.

Following is what I found as far as spark plugs that fit your car:
NGK PLUGS & WIRE SETS
Plug.................GPSERIESBKR5EGPNGK7090[1]
Plug.................IXIRIDIUMBKR5EIX-11NGK5464[2]
Plug.................STANDARDBKR5ES-11NGK2382[3]
Plug.................VPOWERBKR5EY-11NGK2355[4]
Wire Set..........WIRESETRC-EUC071NGK58410

1.Twin Spark
2.Twin Spark
3.Twin Spark
4.Twin Spark

Besides the Standard, if you are adventureous I would try the Iridiums too. I have heard horror stories about people using platinum plugs though.
It seems that the center electrode/mounting get damaged, may be due to higher temps/pressure.

NGK has the following to say for their Iridium Spark plugs:
NGK Iridium IX spark plugs provide unsurpassed performance in auto/light truck and powersports applications. The iridium alloy electrode is extremely durable to heat, corrosion and electrical wear. The fine wire electrode reduces the amount of energy required to create a spark while providing increased ignition efficiency and superior ignitability. The center electrode of Iridium IX spark plugs has an extra anti-fouling mechanism. A thermo edge between the center electrode and the insulator nose provides a gap for a secondary micro-discharge to jump and initiate a self-cleaning process.

Note that the reduced energy to cause a spark may have an impact to the firing timing.

ohlord

OE plugs
12 per engine Updated version of OE spark plugs F8DPER and F8DPP33. Pregapped for normal usage.

$17.95 each list $4.46 each at autohausaz.com times 12 is over 50bucks order so shipping is free.
NGK 7090 is oe style also single side electrode and last time I purchased them for my E wagon They were on sale at napa for $2.79 each
Plugs are a definite DIY item,if you gather the tools and use common sense.
No anti-seize on the plugs and torque them properly.
Since it is the same engine family as the E series m112 engine if you can't find a diy here go to benzworld.org w210 diy section http://www.benzworld.org/forums/w210...1-06-07-a.html
for a nice diy spark plug change how to for the m112 series v6 by member G-AMG