- Mercedes Benz E Class AMG: How to Replace Spark Plugs
Step by step instructions for do-it-yourself repairs
Changing Spark Plugs-05 E500
I have a couple of questions and need some assistance:
I think I have all the tools but am a bit concered if I should adjust the gap. These plugs are gapped as .040 as they come out of the boxs.
How tight should it be in lbs.
Any other tips will be greatly appreciated.
Thanks a lot!

Dan
it was almost impossible to remove em with out it.
Most have found they are gapped properly, some have found otherwise. It's so easy to check.
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I also used the 17mm wrench but mine was straight not offset. It worked but a little of a pain. I recommend to twist the plug cap before trying to remove it to break the initial stick this will make it easier to pull off.
Also when installing you must really press the plug cap on to seat it. If not it will force jumping a large gap and could cause coil failure. So pick an easy one for the first removal and then look at he cap/ plug to see how it fits while it is all out.
You will also need 27 mm torq to remove the coil packs.
Note each wire is different make sure each coil pack goes back to the same position and each wire back to the exact plug.
When unplugging the coil pack use care not to break the lock tab on the plug in the coil. They are replaceable at about $2.00 each but not fun to wait on for delivery.
When you first break the plug loose, stop. I worked it back and forth about 1/8 turn to remove the carbon build up on the end of the plug. I also would remove until it would feel tight then turn to tighten to break the threads free. I never put the plug wrench on and just cranked one fully out for fear of pulling the threads out of the head.
I put a small amount of neverseize on the threads and silicon on the plug cap. I know there are those who will say NO to this,, but it is My car so I did it to make removal a little easier if I do this again.
Overall the plugs are relatively easy to change and if needing changing again I will do it myself.
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Reason is, the dealer (of course) is telling me I should change my wires also. Does anyone know what the recommended change interval is for the wires BTW?
I know that changing spark plugs at the dealer costs around $500. Throw in wires and and someone said dealer quoted them $1900, I do not know how but that is just CRAZY!
BTW when I changed my spark plugs at 80,000, they were in very good condition. They have have lasted another $20,000 without problems.
I know that changing spark plugs at the dealer costs around $500. Throw in wires and and someone said dealer quoted them $1900, I do not know how but that is just CRAZY!
BTW when I changed my spark plugs at 80,000, they were in very good condition. They have have lasted another $20,000 without problems.
But I would say $1900 is a
for plugs and wires.
I have a couple of questions and need some assistance:
I think I have all the tools but am a bit concered if I should adjust the gap. These plugs are gapped as .040 as they come out of the boxs.
How tight should it be in lbs.
Any other tips will be greatly appreciated.
Thanks a lot!

Dan
I have a couple of questions and need some assistance:
I think I have all the tools but am a bit concered if I should adjust the gap. These plugs are gapped as .040 as they come out of the boxs.
How tight should it be in lbs.
Any other tips will be greatly appreciated.
Thanks a lot!

Dan
I don't want to throw you a curveball here but I just went thru this experience last week with identical car, only to discover by accident that I installed the wrong Bosch plugs myself. I had checked many resources for double iridium and all came up with the same 9652 plugs. However, since my engine light kept coming back on after a few short trips, I starting researching what could be possible causes. I went to the Bosch website only to find out that the 9652 was NOT compatible and after talking to two different technicians at Bosch, they both said 6702 was the ONLY plug to use. Said our car can't even use an iridium plug and that a double-platinum wasn't available either. You might want to confirm that before installing it with Bosch.
Also, it is nearly impossible to remove the ignitions coils without snapping the little plastic piece at the top. However, you will want to remove them as they are easy and makes reaching the plugs much easier. Be careful of the little screws and the T30 bit to remove coils as I dropped two of them never to be seen again. LOL.
While you are at it, you might want to change the wire as well since you are going to have them off. I installed NGK as I think they are considered the best.
Good luck.
Last edited by Wildcat55; Nov 21, 2019 at 08:10 PM.
Any suggestions?
i actually was surprised the plugs inside were NGK and not bosch. i did a compression test and it turns out me M112 is very healthy (100+ reading on first crank for each piston!!).
removing the ignition wires with a plug plier was not fun at all. many times i debated quitting but i said **** that, as i imagined some hindu with his devious little smile relishing in any failure of mine.
new plugs are great!













