marktan

Thought I'd report back on an experiment which seems to have been successful (so far). My symptom was an occasional #2 cylinder misfire on my 2005 S600. Under light load, I could run it for hundreds of miles, but if I gave it anything that took her up over 4000rpm, she would start misfiring until I turned the engine off and on again. I've been dreading purchasing another $1200 coilpack (the left one completely failed a couple months ago), but my emissions test is due, so I had to remedy it sooner than later. I figured a repair attempt wouldn't hurt, as worst case would be I replace the damn thing anyway.

Fearing that removing the coilpack from the engine would definitely be the kiss of death for it, I instead cut (melted) the cover of the coil pack off with an exacto blade attachment on my soldering iron while it was still in the engine block (I tried to pry it off gently, but it was so brittle it would have broken apart). Once off and the circuit bard was exposed, I looked at the top of the #2 cylinder coils. I made the observation that on one of them (two per cylinder), the wires leading from the three terminals at the top of the rod that goes into the block to attach to the sparkplug had ALL detached from the circuit board. I regret that I completely forgot to take photos, but if you look at Howard's ongoing S600 repair post, he shows a photo of the inside of a coilpack. If you look at the "round" spots with the three wires in them, you should be able to see what I'm talking about.

The far right connection was just loose and barely touching the terminal. The center was also loose on the circuit board side. The left wire was completely missing (couldn't find it anywhere inside). So I swapped out to a fine tip on my soldering iron and went to work re-attaching all three connections. I wound up creating a new "wire" connection for the left terminal using copper braid desoldering wick. After I was confident all the connections were solid, I re-assembled everything and she runs *perfectly*! Took her out for a testdrive, did a couple hard starts from a stop, ran at higher rpm in lower gear on the highway, and created load by downshifting and engine braking (all the things that guaranteed a misfire before).
I'm really not sure how long this patch job will last (I'm not pretending it's anything but that), but if it buys me a month to get the thing emissions tested and not have to explain to the wife why I'm sinking another couple thousand dollars into my car, I'm fine with that. I figure I'll eventually need a new coilpack, but I'm pleased that it is possible to repair these things given the right type of "breakage".

Looking at the circuit board itself, it seems to me like there is very little that could go wrong with the exception of these wire connections that are easily broken if the rods on the coilpack are twisted or pulled in the wrong way. I suppose the heat could also eventually cause one to fail entirely like my left coil.

A special thanks to Howard for his work on his S600 and the photo of the inside of the coilpack. It gave me the inspiration to try this repair.

haoz129

Congratulation my friend.

Howard

Sgt. Schultz

Post of The Year

!!!

Impressive - esp the part about the in situ fix!

Well done very well done, kudos to both you / Howard for pioneering this and sharing!

and amen on the 'buying time' bit - I soooooooo coulda used 'this' when my 1st pack went daze prior to Xmas (Merry f'ng Xmas)... anything to save wifely face is HUUUGE 8-)

now here I am 'again' w/ last week offering up the 'other one'... I'd attempt yer magicfix but alas she's off to John Nouri @ Broadway Performance Tue for some of HIS magic 8-)...

...and, hello fIdElI+Y heh heh.

(aiming for some "while we're in there's"... TCU flash, some STAR lovin, some muwhahaaa Just Not Right maybe just maybe)

marktan

Update on the repair...after exactly one month and about 2k miles I think the right coilpack finally gave up the ghost.
Had problems starting it this afternoon, and once it did start, it started shaking...Check engine light turned on...etc. Shut down, re-started, ran smooth. Gave her some gas and it started acting up again. Plugged in the computer and it was reading misfires in cylinders 1, 2, 3, 5. cleared the codes, restarted, and misfire in 3, 4, 5 came up. So I think it's time to get a new right coil pack.
I didn't expect my repair to last long, and it did what I wanted it to do, which was to allow me to pass emissions and buy a month or so before having to bite the bullet on yet another coilpack purchase (replaced the left one in December). It also gave me a better understanding as to the construction of the ignition coils. Bottom line: It is what it is.
Although I'm thinking with 2 new coilpacks, an ECU tune may be in order very soon.

DRTYLNDY

Sorry dude. Maybe someone will soon make a "sturdier" less expensive coilpack. Maybe you and Howard.

marktan

Thanks!
I do plan on ripping this one apart once I pull it back out if time allows. I just ordered a new one a couple hours ago. Should arrive on Monday or Tuesday and we will be back in business.

classyS

hey this sounds fun, i definitely plan on learning/conquering such a task in the future to help save costs.. im glad all is fixed! and its quite the discovery..

to my fellow solder'ers - i love soldering.
heres a little mod by cartronics that i found pretty interesting; so i decided hell, why not

https://mbworld.org/forums/s-class-w...artronics.html - 2003 s55/s600 owners pay attention!!

lol the aux cable is 10ft and extends to the back if someone has something interesting on their device theyd like to broadcast

p_mentir

Where did you buy yours? I saw one for sale at $936 on the following:

http://www.parts.com/parts/2004/MERC...icleid=1431942

My 2004 s600 is misfiring. we took the coil pack off and it is definetly busted. My mech said he can get it for 30% off from Merc (he feels bad as I just dumped $5000 on the car - front lower control arms x2, rack (refurb), radiator, rear valve on ABC, new spark plugs, bearings). He won't charge labor either as he has to change the gaskets anyways. Still it's gonna be another $1600... You gotta love this car to keep pouring money into it - sigh...

Good luck fellow gluttons for punishment!!

marktan

Got mine from amazon.com and installed myself. the Standard motors UF-579 ignition control unit is the passenger side. UF-578 is the driver side. Free 2day shipping with prime or $3.99 1day.

p_mentir

You paid $1165?

marktan

I paid $1030...looks like the price jumped.

NRL

I'm starting my DIYer coil pack replacement journey.. for me, it seems like the right coil pack with an older part#. DAS showed all errors that last few times all on the right side.

I saw the write ups but I'm trying to get past the first air box removal? Don't want to break that clip/sensor, on that air box, where do you push it in at?

As far as the air box, what do you have to do to remove it from where it connects to the inlets? Just yank it back towards the firewall?

MRAMG1

There is a great DIY on this located on another planet that has supercars

NRL

Thanks, saw that.. it's also here:

https://mbworld.org/forums/m275-v12-...-pictures.html

But I have questions new questions on pulling the air box out and pulling that hose off the turbo inlet, does it just pull off?

I'm sure it'll be easy the second time around..

MRAMG1

Sorry my friend, I just could not help myslef.

If memory serves me right, there is a clamp, double check with a PM to OXYGEN here.

marktan

There are like 4 torx screws on each air box then it pulls straight off. Then another few to peel back the intercooler (unscrew the metal clamp on the intercooler hoses). Also a "U" clamp from the outlet under where the air box was (metal). Be aware, On the passenger side, be sure to remove the small hose from the manifold pressure sensor on the top of the engine or the nipple will snap off when you peel the intercooler back ($50 part...ask me how I know ).

NRL

Thanks.

I ran into a virgin never been removed airbox (the Coil pack is the original older partno by the way).

With all the screws removed, It just wouldn't let go from that rubber seal.. it finally let go after I yanked and yanked.. sheesh.
On to the intercooler.. Hopefully that was the hardest part.

Do I need that mesh that's part of the intake before the box?

p_mentir

I replaced the driver side coil pack (found online for 950 + 9 shipping). Works great. I have the old one and could send it to you to further your experiments if you pay shipping. It's in the box I got the new one in. Let me know if you want it in the name of science!

1098

wow! where do I find one for 950? my baby has been misfiring as well. got gas last week and 20 min later had to drive home at 60 mph all the way home! car drove like it was a 4cl ha!

p_mentir

The cheapest I found was 935 at the site I showed above but they don't list a phone number (I'm not spending anything over $100 on a site without a number). I called the guys at genuine Mercedes Benz parts (http://www.genuinemercedesparts.com/...&siteid=215306) and they list it at 1050, but I got a break after pleading a little on the phone to 950 + 9 shipping. Two day shipping.

Good luck!

NRL

That's a bit better then parts.com. If your ordering new ones, most likely you'll get the new partno's that supercede the old partno#s.

If your going to do it yourself or use an Indy, when you take the coil pack out, look for oil on one of the red insulator boots, and also on that spark plug thread..

It's either that thin oil that shutdown your coil pack or the coil pack is for sure defective.


I have yet to figure out if the oil is from it misfiring or the oil causes the misfire.. In my case it was near cylinder 1, the two plugs, where the oil filler is above it and past oil might have slipped down into the spark plug cavity hole..
Another theory is the valve cover has a small if not the smallest tiny oil leak filling up that spark plug cavity hole with some oil.

Or just a coil pack going bad slowly (only happens above 2k or 4k rpm).

I've got both my coil packs out now since I'm doing all 24 spark plugs. I'm waiting for the new NGK spark plugs, and as I wait, I've practiced putting in the right and left coil packs over and over so it's no longer a mystery or hard to put those suckers back in. I also plan on using dieelectric grease and will cover the red insulators, and on top of the spark plugs, it should slow down that tiny bit of oil where ever it's coming from?

p_mentir

You may have to change the gaskets - I did that as well and it cleared up the misfiring passenger side. Driver side def bad coil pack (there were burn marks inside one of the cylinders in addition to the oil leaking onto the sparks).

My car has about 110k miles and the gaskets were as brittle as dried up twizlers... No misfiring after the gaskets and coil pack were changed.

Hope that helps!

NRL

hmm, which gaskets? Gaskets=red insulator boots?

So far I've seen the red insulator boots, the spark plugs, the coil pack...

The seal around the valve cover?
Rubber or steel gaskets?

p_mentir

Yes. Under the valve cover (lot of work and you gotta be careful not to let anything get into the turbos). Disclaimer, I watched the guy do it and spent the entire day there - I am no expert. That said, there was oil coming onto the spark plugs and causing misfires - tech thought it was the gaskets and i have to agree after seeing how badly worn they were. The rubber gaskets are around $40 each (the driver side is apparently a b!tch to put on). If you are in there changing the coil pack it's not much more work to do. I estimate 4-5 hours for both if you are decent.

The red things are boots and go over the spark plugs. These will sometimes not come out and can get damaged if you are not careful pulling them out (they can also have dry rot and become quite brittle).

Inspect the coil pack for tell tale burn marks or other signs of damage (they could still be broken if they look good though as it is basically a circuit board under constant stress).

Anyone else more knowledgable is welcome to chime in this is just my experience and I am unfortunately still learning.

NRL

Thanks,
So, just to confirm, the gaskets your talking about are the Red Insulator Boots. If so, yes, I was careful covering the turbo and intake holes..
The puzzle is where does the oil come from? Between the valve cover? or from the oil filler cap (if you miss filling it up)? and it drips right into the spark plug holes (first two near the oil filler)?

or

I'm just wondering if you talking about some unknown to me valve cover gasket inside the valve cover, like he had to remove the valve cover and flip it upside down to get to it..

I've got it all open right now waiting for the spark plugs, so I need to identify this "Gasket".. Preferrably, it's an actual part on parts .com or rockauto.

It's not the actual cylinder head (valve cover) one piece gasket is it?

Thanks