I'm changing my plucgs and its going like poo.All have been very hard to get to turn, I'm on the the 3rd cyl. and one plug barley turns, feels like what I would guess 60 to 70 pounds the next wont turn. Is this common on theses engines. The plugs that I have got out are the long NGK OEM plug.

 

is the block hot. let it cool down for a bit.

 

ice cold, has not been ran since yesterday. In got one out,next cyl is the same thing. worst spark job ever. The plug is clearly to long and carboned at the tip. this is compleatly F up.

 

the only thing i can think is try it hot now? I know thats the wronk thing but what else?

 

Given the circumstances, I don't see very many choices at this time. You can try some type of penetrating lubricant. GL with it and let us know how it goes.

 

I moved to the other side nd it seems to be a bit better, I broke them all lose ns am going to spray PBblaster in all the holes and let it sit.

 

the really great part is that since there so tight if i do break it lose i cant tell when it seats on the gasket to put back. so I may have 3 or 4 plugs that wont hold compression. I'm so happy right about now.

 

That sucks dude. Are you are putting the old plugs back in? You should replace them. I would also run a tap through the each spark plug hole just to clean the threads, then blow out with compressed air. Put some anti seize on the threads and I doubt you will ever have this problem again.

 

Mine all came out hard. Looking at the threads it appeared that some sourt of oily sticky residue had worked its way up the threads over time. I was pretty scared I was going to rip the threads out on a few of the plugs. I put a small amount of antiseize on the new plugs and they threaded in just fine by hand. I think the engine was just slightly warm when I did it.

The factory plugs ARE NOT too long. If you replace them, make sure you get the NGK ILFR6A or Bosch equivalent. These are the only two plugs ANYWHERE I have found that have the proper 28mm reach. All of the parts stores will list the incorrect plugs with a shorter 22mm reach.

 

one left to go, its really stuck.

 

So did you muscle through all of them? Did the spray help?

 

I installed denso iridiums & they fit perfect. $8.00 x 16 = $128.00

I'm pretty sure the stock plugs are iridium as well, made by ngk.

Yeah that spark plug job is one of the worst due to no room to maneuver. Definitely clean out the holes with brake parts cleaner & a small wire brush. You could chase the threads but they are such a pita to get to you might not want to deal with it. Also like said before a small amount of copper based anti seize on the threads will work wonders next time you go to remove them.

 

How long is your wrench? Its all in the lever. My old ones were very tight to remove, but new ones went in easy.

 

I used a standard plug socket, a 3" extension, and a swivel-head ratchet( a standard one would have worked for sure. No universal joints or any other trickery. It was actually much more straight-forward than I expected. I got it done start to finish in under 2 hours. Also, any of you guys that have not yet done the plugs, do yourselves a favor and buy one of those $10 boot pullers to get the boots off. Much easier than the wrench/valvecover trick.

 

Yes a boot puller & mb actually has special tool for this job. It's a swivel socket that is just the right length etc for a perfect fit.

 

yeah I got it done, Brought the engine up to temp and then filled the hole with KROIL, let it cool for about a hour then gave it about 3/4 twist, let it sit for 30 min. then just forced it the rest of the way. I thought there was a fair amount room, just thought for sure I'd pull the thread out. But its done. I used the ngk7090 its shorter. and was about 40 bucks. Seems to run the same, still seems to have a bit of a rough idel.

 

Did you use a boot puller for the wires? They should be replaced when you change out the plugs. Look into some aftermarket. Rough idle at cold start is normal. If its happening all the time, you could have a miss fire.

 

That is poor advice. The only reason to replace a plug wire is if either of the boots are damaged, or if it no longer meets its specified electrical resistance rating. If those factors are in order, you will just be p*ssing money away by buying new plug wires.

Factory iginition systems, including coils and spark plug wires are remarkably robust and are not normally components needing an upgrade.

 

Huh? Shorter? Are you joking? The stock plugs are ngk iridiums > http://www.ngksparkplugs.com/product...r_iridium.asp#

You should be running ngk part # IFR5D10

I would remove them asap before you do any damage.

 

This actual made me laugh out loud, yeah thats the plug and its shorter. same as with any brand you look up.3/4 reach. from what i'm seeing is the factory is replacing the 1.02 reach plugs with the 3/4. I'm trying to figure this out. How did you find the plug for your engine? If you took out one old one and had it cross matched then maybe you have the orignal size but if you like 99% everyone else used the "recomended" plug then its 1/4 shorter than stock.
http://www.densoiridium.com/find_part.php
just drag the curser over the plug and it will give you the specs, you will notice a mix of reach listed.
http://www.sparkplugs.com/results_ap...1&AAIA=1422997

 

"same as with any brand you look up.3/4 reach."

"from what i'm seeing is the factory is replacing the 1.02 reach plugs with the 3/4. I'm trying to figure this out." What are you talking about? Who said the factory plug is 1.02"? I bought my plugs based on what denso recommended. No idea what the reach was. The ones i removed were ngk iridiums private labeled for mercedes with merc logos on them. No idea if they were longer or shorter. The densos seem to work great & my gas mileage has improved as well as my idle.

 

So I just called Mercedes(company) talked to a "prduct advisor" there going to call me back with info. I'll keep you posted.

 

Mercedes is not replacing their plugs with shorter ones. You used the wrong part number NGK plug.

Premium Iridium #ILFR6A
Part # 3588

That is what MB uses and it has been posted by someone that works at the dealership and went to look at current MB replacement plugs for the sake of this same arguement. ILFR6A was printed on them.

From pics below you can see that the plugs used are still the "longer" ones and the part number A004 159 1303 which is the current part number in EPC net for spark plugs using my E55 vin #.

 

Good info, Someone should really contact NGK, Bosch, Denso and Champion and let them know that there puting out the wrong pruduct for our cars. you would also think that with the spark plug shrouded by a 1/4 inch the engine might not run so well but it does.

 

I think you are sadly mistaken. To do this job correctly, you need a mercedes boot puller to remove the wires correctly. Do you have this tool? If not you are damaging the wires by just pulling them off. That can cause rough idle, random miss fires all the way up to a check engine light.

The connections on the wires become loose, if not removed correctly with a boot puller. That will increase the resistance and can cause problems. Might want to check that out, then report back. Just a suggestion.