jeff.bisonett

Hi Guys,

went into the shop this morning for a misfire. Started out testing coilpacks, wires, and plugs... then did a compression test, cylinder 5 was 145psi... then a leakdown test.... 80% leakdown on cylinder 5 and pretty loud out the crankcase, indicating rings.

Question: What should I do?

jeff.bisonett

searching the forum I have found lots of things:

• Rebuild for $2600 here
• AMGSC has had quite a nightmare...here, here, and here
• 996ttr rebuild story here
• BENZGal got a rebuild motor from renntech here

Guess I am looking for some options... or what would you do if you were in my shoes?

JamE55

How much to get it fixed vs getting the whole engine rebuilt? Weigh your options.

MARK CUMMINS

Did the Shop inspect the cylinder wall via boreascope?
If the cylinder wall is damaged the coating cannot be reapplied ..Nicasil
If it needs ONLY Rings then the labor to r/r the engine and head to repair the one piston / rings will not be that bad

If The cylinder Wall is damaged then it has to be bored oversize and then locate the correct oversize piston

Your looking at a block with pistons or another engine 5.7 Time?

Potomac has a Used Engine for sale..That might be a option

BTW What is the mileage on the car?

Esh

Jeff, I would recommend donating your SC to another local W210 owner

Just kidding man, but if something does happen and you're looking to get rid of it, let me know first.

In the mean time, I'm sorry man, that pretty much sucks.

jeff.bisonett

Thanks James... still awaiting some quotes from various places.

no damage visible with the bore-scope... so I'm hopeful that it'll only need rings on one cylinder..

I did see the potomac engine... still waiting on price quotes for rebuild... so we'll just have to see which comes in better.

46,300 miles on the car, s/c has been on for about 13,000 miles

Thanks for the offer...

but I will keep you in mind first if I decide to part anything out

MARK CUMMINS

Was the charger modded with another pulley? ..or just the stock pulley?

This is odd on one cylinder with 13k on the charger..Was software done?
Different spark plugs installed?..Colder?

was a dyno done after the install with A/F?

Interested to see which ring broke...if you tear it down please take a pic of the piston/rings

JamE55

Welcome Jeff. Keep us posted and if there's anything else i can help with let me know. Listen to Mark as well. He's get some pretty good advise since he's worked with MB's for quite sometime.

whipplem104

I would just get a salvage yard engine. For the cost of replacing parts on this motor even if the cylinder was ok, you could get another engine.
I just replaced a customers 55 motor and the engine cost 3300.00.
If you have a tech take the engine apart and start replacing parts you will be really close to that number. Engine tear down and reassemble is going to be 2000 with gaskets not including the piston.
FYI the one I did had a kleemann supercharger also and the intercooler pump quit working and detonated really bad. Broke the piston ring lands and melted them down. Cylinders 5 and 6.

jeff.bisonett

pulley is smaller than stock kleemann pulley
kleemann software was done
colder spark plugs installed

dyno done post install, did not do a/f with sniffer. Hooked up an a/f gauge on the dyno to stock primary o2s (all new o2s at s/c install), never ran lean. I had plans to go back with a wideband but never got around to it.

I'm still unsure what caused the ring failure...

Sounds like a used motor might be better than breaking into the current motor.... though I probably still will just to see how it failed.

Just went out and checked my intercooler pump.... it's still running.

CynCarvin32

I have seen two Kleemann Modified W211 cars with cracked pistons that had misfire and lumpy idles as symptoms.

Both blew the piston apart between the rings and both got lucky in that the cyl walls were fine and the piston was replaced and the motor put back together.

Both cars had a history of issues with software tuning after the airpump relay and ecu flash from the factory. The thought was that they were running running to lean and ended up with cracking due to detonation.

Now you dont have a W211 but that could well be the issue. The rings on the M113 normally are pretty stout. On the other hand I have seen many cracked pistons and heard about even more though the grapevine.

Peter_02AMG

Wow! sorry to hear this about your car Jeff, it's a low mile engine too How did you know your engine have a misfire, what lead to this conclusion?

something for me to look out for if it happen to my engine

thanks

ABALONE

Sorry to hear about this. I hope that it won't be expensive for you!!

I got a bit of a lumpy idle directly (after start up at Kleemann) after the change to Kleemann headers, so I guess It's something else then a cracked cylinder. A friend told me it was due to the different air pressure in the exhaust, really don't know. It's only at idle in natural gear. Never in D at a redlight.

jeff.bisonett

Hi Peter,

I was driving and got a CEL, so I took it easy the rest of the way home and it became pretty obvious that there was a misfire as I was coming up the driveway: The car really bucks and surges and is very rough feeling.

How many miles do you have?

It looks like I'm going to be able to start work on the motor this weekend and then we'll see what the damage looks like.

I hope it won't be expensive either!!

I've heard that the exhaust can get some tension in it. This'll happen if you install the exhaust on a 2 post lift and then set the car down. The tension sort of 'holds' the engine instead of letting it naturally rest on motor mounts. The solution is easy, put the car up on a 4 post lift and loosen all the exhaust fittings then retighten them. If your car is only a little rough in neutral gear with no CEL I don't think that's a misfire.

Peter_02AMG

Hey Jeff,
so a misfire will trip a CEL. that good to know the symptons incase it happen to my car. My car is hitting 68,000 miles and still running strong, it doesn't burn oil at all.

I'm running the smaller S/C pulley, love the extra power but now you got me alittle worry

Well, I hope it not to bad on your repair and keep us updated on what happening. Good Luck Jeff!!

jeff.bisonett

I've got the lower oil pan off... no metal in the pan

going to start working on getting the head off tomorrow

Peter_02AMG

Please take lot of pictures, i like to see what going on. Hope it not to serious.

Good luck Jeff!

JamE55

While you're at it. Port and Polish it as well.

jeff.bisonett

ask and you shall receive

This is the lower oil pan, the chunks are bits of gasket

Engine with the covers off

Coil packs off, fuel rail drained

Valve cover off

didn't get quite as far as I had hoped for, but it's coming along

We'll see what happens once the head is off

Max Hughes

I love it when mercedes owners DIY their motors. They arent has complicated has people make them seem. I had a harder time rebuilding a firebird v6 then I had turboing my m104 e320.

ABALONE

WOW, really great to post pictures of this!! As much fun it is to the see the "operation", I really hope it won't be expensive for you!!

Good luck

SaMaS

Grat job... you should do cams at the same time ....

jeff.bisonett

sorry it's been so long since I've updated...


Here's the super charger/intake manifold off to the side.

Here the cam bridge is off... picture doesn't show taking off the alternator to get to the timing chain tensioner... or the 46mm socket to take off the oil filter housing to get to the cam sprocket bolt

The head off, seconds after removal... don't worry, I cleaned up all that oil.

jeff.bisonett

PISTON IS OUT!


There's a little bit of carbon on the face of the piston.


And there is our culprit... a piece of the piston broke between the oil ring and middle ring


Circled in case you didn't see it on the image above...

Thankfully there was no damage to the cylinder wall, so now it's time to order a new piston!

SaMaS

Great job good to hear nothing else was damaged...