Changing spark plugs - a couple of tips...

[timf]

At 72000 miles I thought I'd change my spark plugs on my '00 ML430.
So I bought 16 of them at $6.40 each from the local NAPA store B4418's 4 tip Platinum.

I did the passenger side first, removed the air box etc and coils. Took about an hour, taking my time.

Then I did the drivers side - I thought it'd be a little more difficult given the electrical fuse box etc getting in the way. Actually took me just under 40 minutes for this side, faster than the first, here's why.

Couple of tips.

1. The hardest part imho is getting the covers of the spark plugs - here's a tip which helped me.

When using a 17mm open ended spanner to pry off the spark plug covers, make sure you counter balance the leverage you're applying to ensure the cover comes off in line with the plug. Otherwise there's a tendency to push down on the cover which actually makes it very hard to remove. Also I gave the covers a slight tweak to rotate them a little first before attempting to lever them off.

2. When doing the drivers side make sure you cover the top of the exhuast heat shield - it has a very sharp edge and will cut your hands.

Hope this helps someone out and save a few $$$

PS there's more detailed info on how to change plugs elsewhere on this site and others - but nothing about how to remove the covers a little easier or how to avoid cutting your hands !

[DUTCH]

If you use the recommended tool - a long handled 17mm wrench with a very nice off set which was originally designed to adjust the valves on the M110 engine, it's a pretty easy job to pop those plug covers/connectors off.

It also makes it easier if you remove the spark coils first. It provides a firmer and safer place (the engine head) to use as your lever fulcrum.

[Q]

Just want to comment that I was able to get all the connectors off to replace the plug wires with a mechanic's gloved hand. Twist and tug ( I won't say where I learned the technique ). The glove prevents the squirting of the blood once it breaks free and gives you a better grip.

[Melcher]

I know this is an old topic, but if you're still interested:
Put a spark plug wire puller tool (rubber coated) on the wire, hold the tool tight with you right hand and use a long pry bar to pry the tool back, using the valve cover as leverage. I don't remember who showed me this, but everyone I show this too swears by it now. It's the best, fastest, and will not distort the wire ends at all.

[DUTCH]

Originally Posted by Melcher

I know this is an old topic, but if you're still interested:
Put a spark plug wire puller tool (rubber coated) on the wire, hold the tool tight with you right hand and use a long pry bar to pry the tool back, using the valve cover as leverage. I don't remember who showed me this, but everyone I show this too swears by it now. It's the best, fastest, and will not distort the wire ends at all.

On the wire, or on the connector? I sure would never try to remove those by pulling on the wire!!

[Melcher]

DERFFF, no. ON the metal resistor. Clamp onto the metal portion, and pry the puller straight back with a pry bar using the valve cover for leverage.
- I should have said that the first time-

[arkie]

O'Reilly Auto Parts sells a K-D Tool Spark Plug Wire Pulling Pliers that worked great for me. It was about $12 IIRC. The pliers are stamped heavy sheet metal and have a set of curved jaws at about 30 degrees and are coated with rubberized plastic. They are perfect for grabbing the metal connector and twisting a little, and the angle was perfect for getting to each plug. I actually removed the airbox on the passenger's side (really easy to do and made access to this side as easy as the driver's side). The whole process took me about 1-1/2 hours as I did not get in a hurry, examined each removed plug closely, and cleaned everything as I went (wires, coils, top of the valve covers).

[DMICHAEL]

I Changed The Plugs In My 98 Ml320.....it Only Took Me 3 Days, 2 Cases Of Beer And A Box Of Bandaids........my Wife Had To Hit Me With A Stun Gun To Keep Me From Ripping The Engine Out Of The Truck.