I've done this job on this model. One first needs to decide on the new
spark plugs.
The specification is: Bosch F 9 DCO or Champion C 12 YCC, both gapped to
.032" (8mm). I chose to "upgrade" to Bosch 4301 Platinum 2 plugs which
have two preset (no gapping adjustment needed) grounding electrodes.
While you're at it a new air filter element may as well be installed.
Then one needs a spark plug socket to fit the plugs and an extension for
your socket set as the plugs are about 4" inside the cylinder head. Also
needed is a large and 10" +/- long flat blade screwdriver and metric
allen wrench to remove the allen bolts from the spark plug cover on top
of the cylinder head. A torque wrench to 20 ft lbs would be good as well.
The right side of the car has the engine air filter and MAS (mass air
sensor). The MAS has two snaps to the air filter box. Unsnap them and
wriggle the MAS out of the connection. Follow the air duct to to top of
the motor, toward the rear of the car is a hold down nut; remove it and
don't lose it. Follow the duct to the left side to its attachment point
to the throttle body where there's a large clamp with a slotted clamping
screw. Use the long flat blade screw driver - from the front, put it
UNDER the arched intake runners to reach the clamp screw, loosen the
clamp. You can now lift, from the right side, the air duct off the top
of the motor and lay it, upside down, to the left.
Use the metric allen wrench to loosen, NOT remove, the ten or so allen
bolts from the spark plug cover. Lift it off keeping it level enough so
the bolts don't fall out (their lengths differ). There's also a slip
into place wire cover on the front left side that just lifts out. In
front of you are three coils at #2, #4 & #6 and three connectors at #1,
#3 & #5.
The connectors pull off their spark plugs the coils' mounting screws
must be removed to access their spark plugs. (These screws are 4 x 30 mm
so if one breaks, that's the needed size.) Suggest you mark each w/ its
cylinder # before removing it so there's NO mistake upon reassembly.
Remove the old plugs and install the new ones, torque to 20 ft lbs only.
Then reattach the three coils (hold the coil tight to the head when
installing its screw) and three connectors, check that all connectors
are seated and reinstall the spark plug cover, the wire shield on the
left side, the air duct. Tighten the air duct's clamp to the throttle
body and the air duct's hold down nut on top of the motor.
The air box has about six snaps to be undone so the filter can be
changed. Unsnap them and remove its top. The paper filter is nested into
the bottom half. (Don't try to reuse the air filter element, small
amounts of dirt can contaminate the MAS.) Remove it and any debris
that's under it. Install the new filter, snap the box together. To
reunite the MAS to the air box moisten its "O" ring with a bit of water
to ease the insertion effort. When its joined snap both snaps.
Done, figure two hours work given the right tools.
Questions?

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© 2008 T.G.Lambach. Publication in any form requires prior written
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El Tico - 16 Mar 2008 22:19 GMT
> I've done this job on this model. One first needs to decide on the new
> spark plugs.
[quoted text clipped - 7 lines]
> Then one needs a spark plug socket to fit the plugs and an extension for
> your socket set as the plugs are about 4" inside the cylinder head. Also
Hey Amigo, I have a brand new set of spark plugs used less than 100 miles,
I swear... They are still in excellent condition, These are "two heads
platinum spark plugs" for C230 - E320. They should fit well. The reason
I don't use them any more because I switched to Iridium spark plugs. I'll
sell them to you at 1/2 the price I paid for. I do not see much different
between the two types in terms of performance, for me it doesn't make
sense to put them back in... I just want to get some money back.. You can
ask me question on how to change them if you like. Let me know if you
like to buy them from me, I will ship them to you by mail or UPS. I have
a paypal account, I am in the NW of US.
Regards,
El Tico.
Dr_Chino - 18 Mar 2008 09:07 GMT
> > I've done this job on this model. One first needs to decide on the new
> > spark plugs.
[quoted text clipped - 22 lines]
>
> El Tico.
Iridium?
how they work?
i pass from Bosch copper to Champion Platinum Power
and works better
thanks
El Tico - 18 Mar 2008 12:24 GMT
On 16 mar, 17:19, "El Tico" <saroman0...@gmail.com> wrote:
> "-->> T.G. Lambach <<--" <"T.G. Lambach at NoHamorSpamcomcast.net">
> wrote
[quoted text clipped - 33 lines]
>
> El Tico.
Iridium?
how they work?
i pass from Bosch copper to Champion Platinum Power
and works better
thanks
Good for you. They works the same way as your regular plug, only they
withstand higher heat.
Tiger - 18 Mar 2008 23:13 GMT
Iridium is good... they last alot longer. Please remember factory plugs
should last 100.000 miles. These plugs are not copper.
Platinum single electrode is okay substitute. I don't recommends putting
anything other than factory plugs.
If the factory plugs comes with two electrodes, then you can put two
electrodes in or equivalent single electrode oif the same grade... do not
downgrade.
I don't remember what year MB start to use these long lasting plugs...
whatever it is, these plugs are not every year tuneup parts. Even copper
plugs on older cars can last 2 or 3 years without a problem. I would say
roughly 30,000 miles.
Dr_Chino - 19 Mar 2008 09:55 GMT
> Iridium is good... they last alot longer. Please remember factory plugs
> should last 100.000 miles. These plugs are not copper.
[quoted text clipped - 10 lines]
> plugs on older cars can last 2 or 3 years without a problem. I would say
> roughly 30,000 miles.
Thanks Tiger
part of my problem was my car (w140 1993 300SE) wasnt original plugs,
local MB dealer (list) uses Bosch F8 !! copper electrode, so it sucks
i ask for Bosch platinum even for import, they cant do it for me.
thats why i choose on Champion from a good friend that owns a MB.
i have read about Itrium but not about iridium spark plugs on street
cars.
now i note a difference, works better, but i still think im not using
"the best" sparkplug
when your local dealer have wrong info youre lost!!!
best regards
Wan-ning Tan - 20 Mar 2008 14:35 GMT
I do not remember the term MB uses. The 96 C280 we own uses the Bosch
Super copper (factory plug). I tried to upgrade to Bosch platinum but
the engine misfired a lot. It turns out that its ignition design
includes the plug resistance. Each coil fires TWO plugs (in sequence).
IIRC, this design is only used in 2-3 years around 95-96, for 2.8
and 3.2 liter M104 engines. We now stick to factory plug. And Tiger is
right: we change the plugs every 30k miles in average (or misfiring will
start).
The 300SE should be M103 engine. I am not aware it ever uses such
design as the C280. However, I would still recommend factory plug.
>>Iridium is good... they last alot longer. Please remember factory plugs
>>should last 100.000 miles. These plugs are not copper.
[quoted text clipped - 25 lines]
>
> best regards
Also, raise the hood to its most open position by releasing each hood
hinge catch so hood goes to vertical position.

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© 2008 T.G.Lambach. Publication in any form requires prior written
permission.
Dr_Chino - 18 Mar 2008 09:05 GMT
On 16 mar, 18:22, "-->> T.G. Lambach <<--" <"T.G. Lambach at
NoHamorSpamcomcast.net"> wrote:
> Also, raise the hood to its most open position by releasing each hood
> hinge catch so hood goes to vertical position.
> --
>
> © 2008 T.G.Lambach. Publication in any form requires prior written
> permission.
good point
6th cilinder its hard to work