Jun 17, 2015, 02:50 PM
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DIY Changing Spark Plugs W211 E320
Senior Member
Joined: Oct 2010
Posts: 341
Likes: 4
From: Columbia, MO
E320 & X166
AutohausAZ only shows 6 plugs required per car for my 2006 E350 4Matic. I have to do mine in the spring so I'm not sure if that's correct (haven't pulled the engine shroud to see how many wires are coming from the coil packs). I did get the special wrench on ebay for $20 so I'm ready when it's time to do this.
Member
Joined: Mar 2011
Posts: 219
Likes: 26
2011 E350, 1998 ML320
I just swapped out my plugs, and I have a couple of things to add.
I did use anti-seize, as a couple of the plugs made some serious noise coming out, and I think in another 100K taking these things out would be problematic if I put them in dry.
I highly recommend flipping over your coil, and looking at the strip of metal on the back, this is how the coil is grounded, and any rust, or oxidation at this point will raise the resistance of the circuit. I did find some corrosion, and cleaned it up with a small wire brush.
I did use anti-seize, as a couple of the plugs made some serious noise coming out, and I think in another 100K taking these things out would be problematic if I put them in dry.
I highly recommend flipping over your coil, and looking at the strip of metal on the back, this is how the coil is grounded, and any rust, or oxidation at this point will raise the resistance of the circuit. I did find some corrosion, and cleaned it up with a small wire brush.
Member
Joined: Jan 2012
Posts: 244
Likes: 4
From: PA, USA
2004 E320 4matic Sedan
My experience....
Today I replaced 12 plugs and leads on my MY 2004 E320 4Matic
- Do buy the 17mm "Mercedes" wrench. It makes removing the old leads really easy
- Do remove the coils, even if you are not changing the leads. The clearance is way, way better and it is easy to do. I don't know how you'll get the 17mm wrench in as a lever if you leave the coils in the way.
- It is easy to disconnect the low voltage connector to the coils. However, the integrated plastic securing clips that hold the low voltage power supply plug to the coils age and fatigue with heat. On two of six coils' leads, these little holding clips snapped off so the power plug is simply pressure fit and gravity keeping them in, so it may no longer be totally secure. I did not attempt to get new ones.
- The coils and the valve covers are well labelled so that you won't forget which lead & plug goes onto which receptacle on the coil. They are labelled "A" and "B". Or just remember "B" equals BOTTOM receptacle on the coil AND "B" equals plug toward "BACK" of car.
- Getting the lead to click back onto the spark plug is difficult. But you can also use the 17mm wrench to help put the lead back on the spark plugs, so long as you push against the metal of the lead and not the rubber/plastic. I used a rubber mallet wedged between the engine and the suspension tower (just as a fulcrum, not to hit anything) to give the wrench something to push against. That worked and I could easily feel, but not hear, the leads seating home that last half inch or so.
- Put the plug leads onto the coil before screwing the coil back onto the valve cover. That way you will get a much better view of whether the bottom lead is pushed far enough onto the coil. Some of the leads were easy to push onto the coil, others need effort. Take care and don't drop a $160 coil.
- And, of course, remember you can raise the hood to a vertical position with the two small levers near the hinge assembly to get better access and more light. Search the forum, or just go and take a look for the pins that engage when you raise the hood and the levers that can move them. Start on the driver's side and then the passenger's, as I recall.
- The plug leads. You will get 8 "short" ones and 4 "long" ones. The 4 long ones are for the very front and very back plug on each bank.
Last edited by ozusa; Feb 19, 2012 at 10:34 AM.
Member
Joined: Jan 2012
Posts: 244
Likes: 4
From: PA, USA
2004 E320 4matic Sedan
ft-lb, but it's also printed on the box the plug comes in
It would be ft-lb, but the little box the new plug comes in will have a torque spec printed on it. (at least it will be printed if it's a Bosch plug box. I imagine NGK would also give a spec and they may well be the same numbers.)
I did this a couple of weeks ago, but I didn't keep the boxes, as I am not quite that sentimental and I can't tell you the number.
It is not necessarily easy to get a torque wrench on every plug, unless you have a good selection of extensions to use and patience beyond mine. The working clearances vary. So you may want to train your elbow to recognize the correct torque on the plugs you can do properly, so you can apply similar torque on the plug(s) you can't. The torque is important for cooling of the plug, but it is not like it's the wing of jet liner that's going to fall off if you are a little bit out. But I know someone will tell you I am lax and it matters more than life itself.
I did this a couple of weeks ago, but I didn't keep the boxes, as I am not quite that sentimental and I can't tell you the number.
It is not necessarily easy to get a torque wrench on every plug, unless you have a good selection of extensions to use and patience beyond mine. The working clearances vary. So you may want to train your elbow to recognize the correct torque on the plugs you can do properly, so you can apply similar torque on the plug(s) you can't. The torque is important for cooling of the plug, but it is not like it's the wing of jet liner that's going to fall off if you are a little bit out. But I know someone will tell you I am lax and it matters more than life itself.
Junior Member
Joined: Feb 2012
Posts: 25
Likes: 2
C320 Wagon
It would be ft-lb, but the little box the new plug comes in will have a torque spec printed on it. (at least it will be printed if it's a Bosch plug box. I imagine NGK would also give a spec and they may well be the same numbers.)
I did this a couple of weeks ago, but I didn't keep the boxes, as I am not quite that sentimental and I can't tell you the number.
It is not necessarily easy to get a torque wrench on every plug, unless you have a good selection of extensions to use and patience beyond mine. The working clearances vary. So you may want to train your elbow to recognize the correct torque on the plugs you can do properly, so you can apply similar torque on the plug(s) you can't. The torque is important for cooling of the plug, but it is not like it's the wing of jet liner that's going to fall off if you are a little bit out. But I know someone will tell you I am lax and it matters more than life itself.
I did this a couple of weeks ago, but I didn't keep the boxes, as I am not quite that sentimental and I can't tell you the number.
It is not necessarily easy to get a torque wrench on every plug, unless you have a good selection of extensions to use and patience beyond mine. The working clearances vary. So you may want to train your elbow to recognize the correct torque on the plugs you can do properly, so you can apply similar torque on the plug(s) you can't. The torque is important for cooling of the plug, but it is not like it's the wing of jet liner that's going to fall off if you are a little bit out. But I know someone will tell you I am lax and it matters more than life itself.
What kind of torque wrench do you think I should get? I just checked Amazon, all of cheap in/lib torque wrenches have terrible reviews. Do you think it's OK buying cheap 20-200 ft/LBS and using it at the lowest setting?
Last edited by aobnitas; Mar 2, 2012 at 11:56 AM.
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Member
Joined: Jan 2012
Posts: 244
Likes: 4
From: PA, USA
2004 E320 4matic Sedan
Torque wrench suggestion
As I understand it, torque wrenches are at their least accurate toward the ends of their quoted ranges, so for the plugs I would not use a 1/2 inch with the range you suggested.
I bought a pretty cheap 3/8 torque wrench at Harbor Freight. It seems to work and I could see/feel it click easily enough, but I have no real way of knowing if it was actually accurate. It cost roughly $20. The range was 5 - 80 ft lb, I think.
I bought a pretty cheap 3/8 torque wrench at Harbor Freight. It seems to work and I could see/feel it click easily enough, but I have no real way of knowing if it was actually accurate. It cost roughly $20. The range was 5 - 80 ft lb, I think.
Junior Member
Joined: Feb 2012
Posts: 25
Likes: 2
C320 Wagon
As I understand it, torque wrenches are at their least accurate toward the ends of their quoted ranges, so for the plugs I would not use a 1/2 inch with the range you suggested.
I bought a pretty cheap 3/8 torque wrench at Harbor Freight. It seems to work and I could see/feel it click easily enough, but I have no real way of knowing if it was actually accurate. It cost roughly $20. The range was 5 - 80 ft lb, I think.
I bought a pretty cheap 3/8 torque wrench at Harbor Freight. It seems to work and I could see/feel it click easily enough, but I have no real way of knowing if it was actually accurate. It cost roughly $20. The range was 5 - 80 ft lb, I think.
OK, I'll get the same one as you. I think the old plugs are inserted at the right torque at the factory, so I think I can check the accuracy of the scale making it click with the old plugs, before I remove them.
Last edited by aobnitas; Mar 2, 2012 at 12:48 PM.
MBWorld Fanatic!
Joined: Mar 2006
Posts: 3,254
Likes: 15
From: Louisiana
03 E500 and Corvette
After reading those negative comment about the cheap torque wrench on Amazon, I'm actually scared to buy one of those...
OK, I'll get the same one as you. I think the old plugs are inserted at the right torque at the factory, so I think I can check the accuracy of the scale making it click with the old plugs, before I remove them.
OK, I'll get the same one as you. I think the old plugs are inserted at the right torque at the factory, so I think I can check the accuracy of the scale making it click with the old plugs, before I remove them.
I found for torque at 14# or so no gauge is good enough. I pull the plug by hand until it seats and is "hard seated" then stop. 30,000 miles ago this worked well for me and my Lycoming engine.
Member
Joined: Feb 2015
Posts: 179
Likes: 11
E240 -2003 E55 AMG -2005
I recently undertook this job it took me a good 2.5 hours only because one of the plugs snapped off during removal. The 17mm removal tool I think is essential however the plug towards the back passenger side here in New Zealand snapped, I has to use needle nose pillars to remove the broken section of plug from coil wire which turned into a mission.
Removing the broken plug from the cylinder head was tricky and took so time given the space to work is mimimal.
All the plugs were original and some were in real tight a breaker bar was required for a couple I plugs. I sprayed the inside of each wire with WD40 and they snapped back on easily without any issues.
Car feels much more responsive, it's a doable job just take your time and try not to snap any plugs on removal.
Good luck!
Removing the broken plug from the cylinder head was tricky and took so time given the space to work is mimimal.
All the plugs were original and some were in real tight a breaker bar was required for a couple I plugs. I sprayed the inside of each wire with WD40 and they snapped back on easily without any issues.
Car feels much more responsive, it's a doable job just take your time and try not to snap any plugs on removal.
Good luck!
Senior Member
Joined: Jul 2003
Posts: 301
Likes: 1
From: Los Angeles, CA
2000 E320 2009 E550
HOW MANY MILES ON VEHICLE WHEN PLUGS CHANGED
How many miles did you have on your vehicle when you changed your plugs?
Member
Joined: Feb 2015
Posts: 179
Likes: 11
E240 -2003 E55 AMG -2005
70k on my 2003 they were original and were well overdue for replacement.
Senior Member
Joined: Jul 2003
Posts: 301
Likes: 1
From: Los Angeles, CA
2000 E320 2009 E550
Member
Joined: Feb 2015
Posts: 179
Likes: 11
E240 -2003 E55 AMG -2005
Member
Joined: Mar 2011
Posts: 219
Likes: 26
2011 E350, 1998 ML320
Glad i did.
Junior Member
Joined: Apr 2015
Posts: 46
Likes: 0
From: Ellicott City, MD
2007 Mercedes E-350 4-Matic
re: Changing spark plugs in w211 (2007 E350 4Matic)
1) How many plugs are needed on a 2007 E-350 4Matic, and
2) (Part #7422/FR8DPP3), Is this the correct part no. since E-Bay says it doesn't fit my E350 ?
I have a P0301 (cylinder 1 misfire) code, Do you recommend changing the coil wires as well , and what is the part # for coil wires and how much do they cost ?
Thanks,
-Irfan
2007 E-350 4Matic (73k miles)
2) (Part #7422/FR8DPP3), Is this the correct part no. since E-Bay says it doesn't fit my E350 ?
I have a P0301 (cylinder 1 misfire) code, Do you recommend changing the coil wires as well , and what is the part # for coil wires and how much do they cost ?
Thanks,
-Irfan
2007 E-350 4Matic (73k miles)
Newbie
Joined: Jul 2017
Posts: 1
Likes: 0
2003 e320ameywilfkamp
Thanks for the great help
Hi there I wanted to thank you for all the help. This write up saved me hundreds of dollars. It was perfect.
I don't think us W211 owners have a spark plug change tutorial on our own so I decided to write up one with pics!
Step 1
Grab a beer or two, this is going to take you at least 1hr and a half
You will need the following tools seen in this picture
Attachment 381529
From left to Right:
-Mercedes Benz V6/V8 Spark Plug boot puller - Available on Ebay for less than $22 shipped
-Bosch Platinum Spark Plugs 12ea part number #7422/FR8DPP33 These are the updated plugs that are OEM in the car and will give you 100,000 miles, don't waste time and money fooling around with +4 or +2 plugs or other marketing gimmicks, its useless. These are available at the dealer for a whopping $12 or from online for as low as $4.37 from Rockauto.com
-3 inch Spark Plug Socket, 5/8 with 3/8 drive,
-3 inch extension 3/8 drive
-Typical Ratchet
-Folding Torx set for the T27 Torx screws on the coil packs, all of those items are available from your local Autozone.
Step 2
Attachment 381530
Open the hood and remove the intake manifold by first removing the front piece as shown in the above picture. Simply pull up and off at the same time.
Then locate the two front tabs holding the intake manifold in place and lift up on them, they will eventually pop up so you can remove the manifold, there are also two in the back so becarefull not to brake them.
Take the intake tubes off
Attachment 381531
Step 3
Attachment 381532
Here you can see the coilpacks for cylinder's 1-3 were going to start out on this side first.
Attachment 381533
Remove the three wire harness that power the coils so you can begin using the torx bit to take out the screws. A normal bit will not work here since it is not long enough and a normal screwdriver will not have the clearance
Step 4
Take the spark plug wires out using the Mercedes Spark plug puller (which is a 17mm open end wrench but with a dip at the end) You will need to move the coils around so you can grab the boot. Simply grab the end of the boot and push against the motor to take them off. Repeat this process until all the plugs are out and coils are off. One coil will have to stay as it is hooked into the wire harnesses.
Step 5
Attachment 381534
Grab the socket and feel around until it goes into the plug hold and grabs the spark plug, make sure its on there.
Take the 3" extension and hook it on the end of the socket like below:
Attachment 381535
Take the ratchet and hook that onto the extension, take off the plug by turning counter-clockwise (lefty loosey righty tighty)
You can speed things up by unhooking the extension and ratchet and hand un-screwing the plugs once they become loose enough.
Attachment 381536
New plug next to old plug
Attachment 381537
Step 6
Put the new plug into the socket and you will simply reverse the way you took the old plug out by fitting it into its hold and hand tighten the plug before you attach the extension and ratchet to finish the job. I did not have a torque wrench so I just tightened it until it became hard to use 1 hand to tighten it.
1 down 11 more to go! Simply repeat this process for the rest of the plugs and the other side as well.
Step 7 putting it all back
Attachment 381538
Make sure you put the coils and plugs on back in the order they were taken off or you will have some serious misfires. Here's a helpful hint, when you hold take off the coils, put them in your trunk and line them up as they would be sitting on the engine. Notice the wire on the top always goes to the right hole and the bottom one always goes to the left hole.
DONE! Now put your intake manifold and tubes back on and go out for a drive and enjoy the new responsiveness and acceleration.
Most annoying part of this task was screwing in and out the T27 screws as on the driver side last bank there is a hose there that limits twist action.
Step 1
Grab a beer or two, this is going to take you at least 1hr and a half
You will need the following tools seen in this picture
Attachment 381529
From left to Right:
-Mercedes Benz V6/V8 Spark Plug boot puller - Available on Ebay for less than $22 shipped
-Bosch Platinum Spark Plugs 12ea part number #7422/FR8DPP33 These are the updated plugs that are OEM in the car and will give you 100,000 miles, don't waste time and money fooling around with +4 or +2 plugs or other marketing gimmicks, its useless. These are available at the dealer for a whopping $12 or from online for as low as $4.37 from Rockauto.com
-3 inch Spark Plug Socket, 5/8 with 3/8 drive,
-3 inch extension 3/8 drive
-Typical Ratchet
-Folding Torx set for the T27 Torx screws on the coil packs, all of those items are available from your local Autozone.
Step 2
Attachment 381530
Open the hood and remove the intake manifold by first removing the front piece as shown in the above picture. Simply pull up and off at the same time.
Then locate the two front tabs holding the intake manifold in place and lift up on them, they will eventually pop up so you can remove the manifold, there are also two in the back so becarefull not to brake them.
Take the intake tubes off
Attachment 381531
Step 3
Attachment 381532
Here you can see the coilpacks for cylinder's 1-3 were going to start out on this side first.
Attachment 381533
Remove the three wire harness that power the coils so you can begin using the torx bit to take out the screws. A normal bit will not work here since it is not long enough and a normal screwdriver will not have the clearance
Step 4
Take the spark plug wires out using the Mercedes Spark plug puller (which is a 17mm open end wrench but with a dip at the end) You will need to move the coils around so you can grab the boot. Simply grab the end of the boot and push against the motor to take them off. Repeat this process until all the plugs are out and coils are off. One coil will have to stay as it is hooked into the wire harnesses.
Step 5
Attachment 381534
Grab the socket and feel around until it goes into the plug hold and grabs the spark plug, make sure its on there.
Take the 3" extension and hook it on the end of the socket like below:
Attachment 381535
Take the ratchet and hook that onto the extension, take off the plug by turning counter-clockwise (lefty loosey righty tighty)
You can speed things up by unhooking the extension and ratchet and hand un-screwing the plugs once they become loose enough.
Attachment 381536
New plug next to old plug
Attachment 381537
Step 6
Put the new plug into the socket and you will simply reverse the way you took the old plug out by fitting it into its hold and hand tighten the plug before you attach the extension and ratchet to finish the job. I did not have a torque wrench so I just tightened it until it became hard to use 1 hand to tighten it.
1 down 11 more to go! Simply repeat this process for the rest of the plugs and the other side as well.
Step 7 putting it all back
Attachment 381538
Make sure you put the coils and plugs on back in the order they were taken off or you will have some serious misfires. Here's a helpful hint, when you hold take off the coils, put them in your trunk and line them up as they would be sitting on the engine. Notice the wire on the top always goes to the right hole and the bottom one always goes to the left hole.
DONE! Now put your intake manifold and tubes back on and go out for a drive and enjoy the new responsiveness and acceleration.
Most annoying part of this task was screwing in and out the T27 screws as on the driver side last bank there is a hose there that limits twist action.
Super Member
Joined: May 2003
Posts: 967
Likes: 77
From: Long Island, New York
2018 E400 4matic Wagon
