Spark Plugs

Can anyone enlighten me on how to change the plugs on 1997 E320

3.2L 6cyl engine. I live in the Virgin Islands so I am on my own with no MB Mechanics. Anything will help.
Reply to
chasarthur
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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?

Reply to
-->> T.G. Lambach

"-->> T.G. Lambach have two preset (no gapping adjustment needed) grounding electrodes.

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.

Reply to
El Tico

Also, raise the hood to its most open position by releasing each hood hinge catch so hood goes to vertical position.

Reply to
-->> T.G. Lambach

On 16 mar, 18:22, "-->> T.G. Lambach

Reply to
Dr_Chino

Iridium? how they work? i pass from Bosch copper to Champion Platinum Power and works better thanks

Reply to
Dr_Chino

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.

Reply to
El Tico

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.

Reply to
Tiger

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

Reply to
Dr_Chino

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 eng> >

Reply to
Wan-ning Tan

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