So I pulled the head off... guess what? *DON'T OPEN IF YOU HAVE A WEAK STOMACH*
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From: Puerto Rico
2005 E55 AMG
That is absolutely a fueling AND/OR ignition timing problem. I've seen this kind of damage a million times from knock. Since it was number 8 and people here seem to normally pop number 8, than I can assume that the problem is fueling over timing. But that is not a failure that occurred just because the part was defective or something like that.
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Joined: May 2011
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From: Baytown, Texas,USA
C300 SPORT
Fueling problem?
That is absolutely a fueling AND/OR ignition timing problem. I've seen this kind of damage a million times from knock. Since it was number 8 and people here seem to normally pop number 8, than I can assume that the problem is fueling over timing. But that is not a failure that occurred just because the part was defective or something like that.
Is this an octane issue or fuel deliverly to cylinder issue when you say above "fueling and/or ignition timing" problem? Just wondering. Thanks
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From: Bay Area, CA
E55 AMG, 72' Toyota Carina, 63' Ford F100, 72' Mercedes 250c, 15' Harley Davidson Softail
That is absolutely a fueling AND/OR ignition timing problem. I've seen this kind of damage a million times from knock. Since it was number 8 and people here seem to normally pop number 8, than I can assume that the problem is fueling over timing. But that is not a failure that occurred just because the part was defective or something like that.
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From: Houston
CLK-63 BLACK/2014 E63S/2013 ML350
That is absolutely a fueling AND/OR ignition timing problem. I've seen this kind of damage a million times from knock. Since it was number 8 and people here seem to normally pop number 8, than I can assume that the problem is fueling over timing. But that is not a failure that occurred just because the part was defective or something like that.
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From: Caribbean/Florida/Colorado
E-ZGO 53hp., 1999 E 430 sport, 2004 E 55, 2008 Tahoe LTZ on 24"s
Oh Ouch, don't worry it can be fixed, chin up.
I would replace the head though, warped aluminum heads after a thermal and mechanical (fod) event, even resurfaced never stop warping, you should be able to find a good used one. Head bolts and threads in block need to be checked before replacement head gets torqued.
From what I see your cylinder looks serviceable, I think you may have lucked out.
for those that have not read the Head thread,
https://mbworld.org/forums/w211-amg/...pped-head.html
I would replace the head though, warped aluminum heads after a thermal and mechanical (fod) event, even resurfaced never stop warping, you should be able to find a good used one. Head bolts and threads in block need to be checked before replacement head gets torqued.
From what I see your cylinder looks serviceable, I think you may have lucked out.
for those that have not read the Head thread,
https://mbworld.org/forums/w211-amg/...pped-head.html
Last edited by Yacht Master; May 18, 2011 at 12:14 PM.
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From: Baytown, Texas,USA
C300 SPORT
Agreed. jumpinjack it's most likely caused the inferior design of the stock fuel rails not being able to deliver fuel to the #8 cylinder causing a lean mixture. not usually a big problem on stock cars, but on modded cars running higher boost it definately comes into play as the OP did note that he was doing a number of WOT pulls.
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From: Tacoma WA
Bicycle
Detonation(knock) is what cause's the damage, It may be due to a few diffrent things, An engine that is to lean will have detonation, a car with to much timimg for the octane used with detonate, Increase engine temps with lower the threshold, hot spark plug heat range, sharp edges in the cumbustion area. so on so forth.
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From: Puerto Rico
2005 E55 AMG
By that I mean lack of fuel ( or too high an air to fuel ratio ) OR the ignition timing is too advanced for the octane being used. In any case, I'd bet my money of fueling. Although he apparently had replaced piston 6 a while back which could mean that the timing is the actual culprit, although timing issues tends to leave pitting on the pistons and the pistons look fine ( except the one that blew but the pitting on that one is because of the ring land bouncing a billion times inside the chamber ) . He's going to have to rebuild and retune to find out.
Last edited by GT-ER; May 18, 2011 at 04:03 PM.
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From: Bay Area, CA
E55 AMG, 72' Toyota Carina, 63' Ford F100, 72' Mercedes 250c, 15' Harley Davidson Softail
Ok i could be wrong but it just looks like too clean of a brake, it just doesn't look like any other number 8 piston failures I've ever seen on these motors, didn't benz_addict just replace this piston with a used one ?? was piston to bore clearance checked when the motor was reassembled,
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From: Puerto Rico
2005 E55 AMG
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From: Pittsburgh,PA, Cambridge, Ontario, CN
2003 S210 3.8L Brabus wagon
That piece probably did not explode to a million pieces but may have done seat and cat damage depending upon velocity out. Are the valves bent? What about the bottom end?
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From: Puerto Rico
2005 E55 AMG
It bent the exhaust valve from what I can see. It probably just broke into smaller chunks before escaping the chamber through the exhaust valve, damaging it in the process.
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E55 AMG, 72' Toyota Carina, 63' Ford F100, 72' Mercedes 250c, 15' Harley Davidson Softail
Thread Starter
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From: Toronto
V12TT
piston is out
Uploaded with ImageShack.us
Uploaded with ImageShack.us
Uploaded with ImageShack.us
I'll have to hone the walls there's a deep scratch. I'll also need fatter rings hmm
Uploaded with ImageShack.us
Uploaded with ImageShack.us
Uploaded with ImageShack.us
I'll have to hone the walls there's a deep scratch. I'll also need fatter rings hmm
MBWorld Fanatic!
Joined: Jun 2010
Posts: 4,173
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From: Puerto Rico
2005 E55 AMG
piston is out
Uploaded with ImageShack.us
Uploaded with ImageShack.us
Uploaded with ImageShack.us
I'll have to hone the walls there's a deep scratch. I'll also need fatter rings hmm
Uploaded with ImageShack.us
Uploaded with ImageShack.us
Uploaded with ImageShack.us
I'll have to hone the walls there's a deep scratch. I'll also need fatter rings hmm
MBWorld Fanatic!
Joined: Jun 2010
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From: Puerto Rico
2005 E55 AMG
You'd be surprised how little a scratch will affect performance and durability. It's not ideal, but compared to the options it's pretty much the only option that's acceptable. I've replaced pistons on engine with old used rings and without even cleaning the sleeve wall from dirt, particles and scratches and they've worked great. AMG's aren't any different.
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From: NJ/Greece
2006 CLS55 & 2002 SL55 (R129) Silver Arrow
Surprisingly your cylinder wall looks to be in great shape.
The scratch that you mentioned, are you referring to the straight dark line that is visible in the picture (bottom left)?
The scratch that you mentioned, are you referring to the straight dark line that is visible in the picture (bottom left)?
Thread Starter
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From: Toronto
V12TT
my finger nail is getting *caught* in that 1 deep scratch rest of the wall looks smooth. What if I don't hone it?
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MBWorld Fanatic!
Joined: Jun 2010
Posts: 4,173
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From: Puerto Rico
2005 E55 AMG
my finger nail is getting *caught* in that 1 deep scratch rest of the wall looks smooth. What if I don't hone it?
Uploaded with ImageShack.us
Uploaded with ImageShack.us
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Joined: Dec 2009
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From: SOCAL
2004 E55
