Gilly-Spark Plug Change

[roadsession]

Gilly,
Thanks again for your quick response.
I am thinking of doing a spark plug change on both cars - '97 c230 and '99 ML320.

I know the ML is a tougher job. But what about the '97 c230 - is it relatively straightforward/easy - I mean easy access and just a standard spark plug wrench, etc... and do you know the torque setting when putting in new ones?

Thanks,

[Gilly]

Sure, the 111 motor is easy to change. Just have to remove the air intake tube going across the valve cover, then the center plate that covers the plugs. It's all downhill from there. No special tools required, nothing needed from Mercedes anyways.
Plugs in this are torqued to 28 nm, same as the 112. You can gap the 111 plugs at .032" (.8mm), but the platinum plugs in the 112 motor (the ML) I wouldn't gap.

Gilly

[roadsession]

Hi Gilly,
Thanks.
I just put in a big order thru fastlane for a whole bunch of stuff.
I now have the confidence to do it myself.
(Now that the car's done with warranty, I want to try to do some of the simpler stuff myself).

BTW: Readers of this post - I just had brake fluid and coolant flush done by the dealer. Many little nuances it seems - and for $200 for both, it was well worth the 'security' of not doing it myself and leaving it to the pros...

-D

[tabo]

Are you going to use OEM from mercedes parts? or aftermarket?
Bosch Platinum Plus +4 #4418? I think OEM is most likely the same.. Gilly are the OEM ones have 4 gaps as well? the gaps don't need to be adjusted for the bosch platinum plus +4 #4418, it seems all the new mercedes uses this expensive sparkplug on their vehicles.

[roadsession]

I plan on using the regular Bosch plugs that are listed as OEM part for the year/model...

I thought of switching to platinum but read somewhere that it wasn't recommended for all cases...

Here's a post that had me worried.... (Plus regular copper plugs are less that $2 ea)
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Bud
Senior Member

Registered: Jul 2002
Location:
Posts: 161
Actually, new Mercedes engines all have platinum plugs and these engines run hotter than previous engines. However, it IS true that platinum plugs should not be used in engines prior to the current 3-valve engines. The older engines were designed to operate best with Bosch copper plugs.

Platinum plugs are designed to last longer not because of the use of platinum but because the tip is protected. The result is that they are not as effecient (at least in older engines) as a normal copper plug.

The recommendation is correct, no platinum plugs prior to the current engine line.
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[tabo]

Hmm.. thats odd, since Mercedes OEM spark plugs costs $10 canadian each (same price as bosch platinum +4) .. $2 US = $3 canadian sounds like a great deal.. but I believe non-platinum spark plugs have shorter lifespans than plantinum plugs.. so you will actually be changing them more often(more chances of not installing them properly), you have to remember the car is heavy and the engine needs to work alot to get it moving... can those regular spark plugs take the load? btw: you will need 12 spark plugs for your ML.. not sure about your c-class. For the price I believe your spark plugs only have 1 gap, whereas the #4418 have 4 gaps...

[roadsession]

Hi Tabo,
Yes, you are correct. I am getting the platinums for the ML, but getting the Bosch copper OEM spec'd for the C230...

[tabo]

#4418 for both of your cars... sorry its really unclear but this website won't let me post anything over 65k =(

Was present when my plugs were changed at the shop. Both the original and new plugs look just like standard plugs. That is they do not have any recess as in the Bosch Platnium+4. I bent the prong on one old plug and verified that there was a small shiny section which, presumably, contains the Pt layer. There was very little indication of wear at plug change: 95k miles.

[Gilly]

I recommend replacing the 112 engine plugs at the recommended intervals if only to get them out before they can seize into the head. Yes, they are a standard looking plug (1 ground, not 2 or 4)
I believe the M111 plug is the Bosch F8DC4 "Super", which is what I would stay with.

On the 112 engine, several owners have commented that the engine seems to have better power after plug replacement at about 100K miles. The observed plug wear always does seem minimal on the 112 engines.