Hi, I've attempted searching for these topics but my unfamiliarity of MB has me desiring more specific hits for my situation than I have found so far.

I have a 2002 S 500 (5.0l V8, 16 plugs and wires, 8 waste spark coils) in the family that is overdue for spark plugs. I want to replace the wires as well. As a mechanic I primarily work on domestic vehicles hence the unfamiliarity.

MB prices the wires individually (unless I didn't understand correctly) at between $33.50 and $52 per unit (list). With a standard shop discount that is still in the mid $500's after tax. With the local dealer's matrix pricing however, they tack on another 25% to that. Ouch! I have never dealt with MB dealerships personally and would be just as happy getting them elsewhere, as long as they are OEM or OEM quality.

Here at Peachparts and via Worldpac redistibutors there are sets for approx $300 in Beru that appear to be identical looking from the pics, and even a Bremi set that looks OEM for approx $200. $200 seems reasonable for 16 short wires in a discounted kit, $300 doesn't sound too bad either. Would Beru or Bremi quality/fit both stand up to OEM wires or no?

Regarding plugs, there are 4 recommendations in Alldata. I can't find an exact aftermarket match but the makes I would consider are Bosch, NGK, and Beru. Checking out aftermarket sources the "most correct looking" Bosch plug is a single tip platinum, not like the crappy Bosch platinums for $2 at Autozone but more like modern OEM style thin protruding platinum electrode similar to many NGK offerings. NGK suggests a host of different types, even conventional type plugs. With this list and variety it is hard to imagine that most of these are truely "correct". I want to avoid potential "ghost" misfire counts and other nuisances that only correct plugs can guarantee. Do you have insight into the exact replacement brand/part# in the aftermarket or do you recommend MB plugs to be sure?

Finally, 3.0 hours to replace plugs (from Alldata) sounds a bit excessive for what the job looks like. Am I going to run into any problems that aren't obvious? It looks really straight forward though; remove a cover and some ducts, 8 coils, 16 wires, swivel socket for the 16 plugs, torque to 28Nm, done. Am I missing anything?

Wow, this post got long. Thanks for reading to the end!

I went to Bosch dot com and looked up the part number for a set of ignition wires (all 16). For my car, a 2002 CLK430, the part number listed was 09850. It's probably the same for your's, but you should double check. Then I started hitting reputable Internet parts stores. I found them for $185.

The spark plugs for all M113's (430, 500, 55) with ME 2.8 (2001 and later) are Mercedes Benz part number 004159190326, which is Bosch part number FR8DPP33 - they are both the exact same part.

Personally, I wouldn't change the wires unless they appear to be damaged (mine are still OE). I used a sparkplug wire remover (puller) to ensure they weren't damaged when I changed the plugs. They will probably be damaged if someone simply pulls them from mid-wire. Changing the plugs on an M113 is straightforward. Your engine bay may be larger, which will be beneficial for some plugs. I left the coil packs connected to the wiring harness, and the "coil side" of the spark plug wires attached. I simply unplugged the "plug side" of the spark plug wires, unbolted the coil packs, slid them back, and then changed the plugs. On my car, removing the windshield/headlight washer tank opened up a lot of room. Other than the driver's side / rear plug, the rest were straight forward. I couldn't see the driver's side rear. I had to use the Braille method.

I hope that helps.

Yeah, I saw that too. I have a fair amount of experience with "other" besides domestic vehicles (no MB experience however) and have purchased euro OE and OEM parts many times, so my detector went up when I saw a Bosch wire set for <$200. The pic doesn't look right, the price isn't high enough to feel confident that they are true OE, so I'm pretty sure these are Bosch aftermarket division parts, which I wouldn't touch no matter how cheap. The Bremi were only $200 and "looked" correct, but that price worries me also.

Thanks, that number is very helpful. It's nice of the local dealer to sell them for $20 each when they list for about $8 :-)

We'll be changing the wires at any rate, he just wants it done and it's the only way I'll help him. Thanks for your very helpful reply. I'm glad it is as straight forward as it looks.