NitrogenBalance

Hey guys,

I am two weeks into my 98' C43 with 45,000 miles. Having all fluids flushed and refiled friday and went ahead and changed my cabin filter and replaced the air filters w/green yesterday. I plan on doing the tranny fluid around 50,000.

Was poking around the engine bay and being so used to replacing plugs in previous autos I was wondering what the life span on these plugs(stock) are???

If you guys see replacing them as a good idea what brand seems to stand above all????

THANKS.

Kestas

If they are regular plugs, they are usually changed every 30K. Platinum-tipped plugs last longer, but not the 100K that marketers claim - I'd give them 50-80K, tops. Just pull the plugs in your engine and inspect them. The plugs should speak for themselves.

Use original equipment. People have reported problems with platinum plugs in a non-platinum MB application.

E55AMG99

I wouldn't even let them go that long. If you have any kind of drop in performance, mileage or notice any misfire, go for the plugs. Not cheap but when my E55 starts to misfire at high RPM on hot days, a new set of plugs all but eliminates it. A minor and almost undetectable (1-2 tenths) improvement in MPG too.

I change plugs on all my 2 strokes every year regardless of how many hours I put on them. Cars and other 4 strokes vary depending on how old the motor is but usually well before 25,000 miles.

PTE

I just happened to Change the 16 plugs on my CLK 5.5 amg. W209. car has 11110 miles on it. I brought the car used. So I've been over it. The mtr had a slite missfire only when cold . The ones I pulled out Were NGK. The Gap has opened up to .038 , some as hi as .041.
The factory gap is suppost to be .031 for this model year. I don't know if the 430 has a different ign system , but base on what I measured , they opened up about .001 per 1000 miles of use?? I installed Champion RC12PYP . Cold start missfire is gone.

mleskovar

What's the book say? Lead free gas and platinum tips have extended plug life considerably. Whatever you do make sure you go with recommended....why put in an unknown?

E55AMG99

The gap should not open up that much under normal use. If the old plugs were NGK, they come pre gapped at .039. I don't know if that is the right amount for this plug in this engine but the previous owner probably never checked. He might have put in the wrong heat range as well.

The Champion RC12PYP is a double platnium plug that is a direct replacement of the OEM Bosch. It is also pre gapped at .032.

NitrogenBalance

You guys are awesome!

StapleGun

What is the spec Bosch plug for C43? Thanks in advance...

E55AMG99

I believe it is the B4418 sometimes listed as F8DPP332 and even F1000-61924....at least that's what I have in my notes for my E55. they should be the same.

PTE

Hi Folks:
I went to the owner manual to look up the gap . I couldn't find it in the engine compartment , Or up on the hood. Went to pg 348 . Technical Data. (Purple Tab) And found it At , CLK 55 AMG . They list a , NGK ILFR 6A . At .031 gap opening. The ones I pulled out said NGK _R_ on the white insulator. Had to get out a magnifying glass and look on the Flange below the 5/8ths Hex and there were the letters & number types. IFR6D 10. The thread length & hex was right , Heat range was right ,It was a resistor/suppressor type . If I remember ,10 means it has a slighty taller J ground strap . So to keep the Platinum pads parallel for.040+ gap sizing ??. But the owners manual says >.031. (Small conflict). So I called Champion tech line in Ohio. I get several Choses. Std , RC12 ( no Platinum) #2 , RC12YP. Platinum center electrode ,only. #3 ,RC12PYP , Platinum Center electrode & J ground Strap.
Well after removing the driver side spark plugs . There was only one chose for me , RC12PYP. I asked them about the gap size. I was told to consult the owners manual or service manual. At that time I had only the owners manual to go by?? So >.031 it was. I got a Service manual C/D coming . I know that some times they can change specs in the middle of a product year . Gap & plug type & style.
I did notice that they listed for the CLK 320 a .039 gap . But a different NGK spark Plug.. Car runs great & smooth. .

PTE

P/S E55AMG99
Thanks for the heads up. I know the heat range is right , but was confused on the gap thing. Thanks for the insite & Info. This is why the forums is good for Shared informatiom.
Again Thanks ___PTE___

mleskovar

So why are you considering changing the plugs? Did the manual give you a plug replacement timetable? I'm annoyed by the "it can't hurt to put new parts in" mentality. It can, and often does cause problems when you 'fix' something that isn't broken. Think about it....the best you can hope for is that it still runs OK. Why do I care? I think we spend more time trying to outwit the engineers that design the cars than following their recommendations and do more harm than good in the process. But it's your time and money so go ahead and waste them if you want.

E55AMG99

NGK IFR6D-10 is an Iridium plug made for OEM! When did MB start using Jap plugs?

PTE

Well ,,,,NGK is what I removed from the engine . That is the only make of spark plug ,it list in The CLK-Class operator's manual, for the CLK 55 AMG?? that came with my 2003 . Don't know when they went too Ngk as an alternet parts source. And It is Stamped (Japan) on the flange below the 5/8th hex Next too the ILFR6 D10.
But they do list the Bosch F8 DPP 332U AND NGK PFR 5R-11 for the 320 & 500

Wish I had a way to show you the plug color. It was more gray than Tan/white. I did by the car used . Mercedes history shows. Rotors & brakes on the front has been replace. Complaint of steering wheel shake when brakes where applied . I got it from a 30ish guy .Who just brought a 05 Porsche 996 . My Guess is that this car was run Hard . I'm trying to just check it over for any small details that may need Att:. Found both door seals , at the bottom Drupping , Radio preset buttons # s 4,5,& 6 not working. I just got it back from the area MB dealer . They replaced the door seals & radio. I had them do a oil & oil filter Change.

Peace of mind for me. Not Knowing the pass history or the previous owner driving Habits. This is a good forum and good shared informatiom. THANKS AGAIN PTE

E55AMG99

Re-read his first post in this thread. He was trying to cure a misfire and it looks like he was successful.

NitrogenBalance

I think he ment that it ran smooth after he installed the new plugs. I agree that replacing things for no reason is dumb but I have always owned large trucks and basic maint. on those included plugs changes. Whenever I would change them the trucks would run awesome and the old plugs were always roughed up. The reason I started this post is that I was curious as to what type of "life" a spark plug has in an AMG V8. I will inspect and if they are bad looking I will change. Seems dumb not to check or change them for the effort involved.

StapleGun

Hey E55AMG99 thank-you for the prompt reply, I appreciate it!

mleskovar

I was referring to the post that started this thread....no problems mentioned. I'm still curious what the book recommends. If no problems are noticed then why not follow the recommendation? Unless you have a fouling problem plugs don't just fail and leave you stranded. Anyone out there have a C43 owners recommended maintenance booklet?

E55AMG99

Yes, I see what you are saying.

I'm guessing based on what my E55 book says that they are recommended to be changed at 100,000. Based on experience, I looked at mine at 20,000. They looked they were sandblasted with #100 grit! Changed them out and found that it cured my high RPM misfire. Don't always trust the book but of course, your mileage may vary.

NitrogenBalance

The reason I started this thread is that I am two weeks into a pre-owned C43. Having never driven one I'm not 100% sure of what to expect. If the car is running at 80% what could I compare it to??? The previous owner was a woman(I hope there are none here to yell at me ) so the car was driven about 5000 miles a year. I'm sure it wasn't pushed hard but I'm also sure that I've witnessed women at gas pumps putting 87octane in $90,000 autos because it is cheaper gas.....what I'm saying is that I'm not sure the owner new what the car was and the attention it needed. Basically doing a check on everything maint. orriented to be safe.

E55AMG99

Too damn funny!