jdupa

Preparing for the spark plug change (80K) on my E350, I removed the torx screws that hold the ignition coil. Disconnected the electrical connector (ignition coil end) an am stuck at this point. Should I now pull hard on the coil itself, to remove it from the spark plug cavity? Some recommend using the 17mm open end offset wrench to remove the coil? where to position the wrench to aid in this procedure?
Please help, I don't know how to proceed next.

vettdvr

Yours is an 06 mine is 03 and slightly different and I have changed all 16 plugs in my E500.

Here is what I would do. After you have it free exclusive of removing the plug boot assembly from the plug twist the boot just enough left and right to break the friction loose. Then I used a 17mm wrench at the top of the insulated metal part of the plug boot and popped off the plug boot. I would NOT pry on the plastic coil for fear of breaking it $$$$. Just remember mine is a bit different but I think yours will also come off if you rotate it enough to break the plug boot friction.

shardul

iTrader: (1)

gently pull on it

jdupa

Thanks to all
Pulling on the coil and boot assembly (one part for this engine) did the trick, and it pops out from the spark plug cavity (really loud) No special tools required, unobstructed access, easiest spark plugs change ever. Made sure to torque to 23Nm.
Strangely, the passenger side plugs were the original BOSCH units, whereas drivers's side was populated with NGKs, hmm. Unless the previous owner replaced one side only?

Thanks again.

gdinerio

jdupa, I will be changing my spark plugs (81k on my e350) in the next week or so as well and had a couple of questions:

1. How many plugs will I need to purchase? (6 I assume)
2. Will I need to change the spark plug wires as well?

vettdvr

2 / cylinder.

No unless you break one. They are each individual part numbers and expensive. Be sure to break the boot free by rotating BEFORE pulling up and breaking the wire.

gdinerio

Thanks for the quick response Vettdvr, its very much appreciated.

Dexion

The DOHC 3.5 motor uses 6 plugs while the SOHC 3.2 uses 12 plugs or 2 per cyl.

lkchris

And the DOHC motor doesn't use spark plug wires.

TheGreatOne45

the e350 gasoline engine is a dohc motor?

starbrite

That's correct.

lkchris

http://en.wikipedia.org/wiki/Mercedes-Benz_M272_engine