Bad skipping/non-firing cyl. on my way home!
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From: Connecticut, New Haven
95' AMG SeeThreeSix
Bad skipping/non-firing cyl. on my way home!
Hey guys,
On my way home yesterday I noticed that upon accelerating the car was really jittery and lost its "torquey-ness". Note: this happened out of nowhere getting on the highway. At a stop the idle was REALLY awful and shaking the heck out of everything. When I got home I checked that all of the wires were getting spark, no dice. I pulled the spark plugs one by one this morning before work, I started pulling them from the distributor back. They all had a fair amount of crusty buildup that I wire brushed away. Then the rear plug.....by far the cruddiest one of the bunch and stunk of gasoline! Bingo! Cleaned it up and shes back to the good ole normal uneven idle
. I know that I'm in for a new headgasket soon, and I assume the crud buildup Im scraping off of these plugs is burned up coolant. I think this would make sense since that the rear plug was the worst and this is where the M103 head gaskets have a thin coolant channel known for failure, correct? All in all, this engine is such a workhorse. Not much can kill it.
On my way home yesterday I noticed that upon accelerating the car was really jittery and lost its "torquey-ness". Note: this happened out of nowhere getting on the highway. At a stop the idle was REALLY awful and shaking the heck out of everything. When I got home I checked that all of the wires were getting spark, no dice. I pulled the spark plugs one by one this morning before work, I started pulling them from the distributor back. They all had a fair amount of crusty buildup that I wire brushed away. Then the rear plug.....by far the cruddiest one of the bunch and stunk of gasoline! Bingo! Cleaned it up and shes back to the good ole normal uneven idle
. I know that I'm in for a new headgasket soon, and I assume the crud buildup Im scraping off of these plugs is burned up coolant. I think this would make sense since that the rear plug was the worst and this is where the M103 head gaskets have a thin coolant channel known for failure, correct? All in all, this engine is such a workhorse. Not much can kill it.
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From: Connecticut, New Haven
95' AMG SeeThreeSix
Thanks for the reply! I knew I'd hear from you, your the master when it comes to this stuff. How would I go about checking to see if there is oil mixed in with the coolant? I don't have weird colors or smells in the coolant reservoir last time I checked. I'm thinking about a coolant and oil change after work today seeing as I have never flushed the coolant since I have owned the car, just topped it up on rare occasions. As for an oil change.....I'm way overdue, I just figure that because I need to put 2 quarts in a month to compensate for leakage I can extend oil change frequency 
.
A head gasket is a definite repair in the near future. Oil is leaking from the exhaust side, rearmost part of the head. The front timing chain cover is leaking like crazy as well.....
.A head gasket is a definite repair in the near future. Oil is leaking from the exhaust side, rearmost part of the head. The front timing chain cover is leaking like crazy as well.....
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Joined: Feb 2008
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From: Orland Park, Illinois
1994 E320 (current)
Had the same problem with my m104 that ended up being a coil. It started off light then eventually about 2 months later I would drop 2 cylinders on acceleration. At idle you foten won't realize you have an issue but under load that bad boy will arc like nuts. That doesn't necessarily translate to your 103 but it may be electrical in nature.
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From: Connecticut, New Haven
95' AMG SeeThreeSix
I originally thought it might be ignition related, however, that 6th spark plug had no possible way to arc, it was stuffed with crust and crud. As soon as I scraped it off, popped it back in, the car ran perfect. Could a bad coil cause excessive crust buildup?
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From: Orland Park, Illinois
1994 E320 (current)
What color was the crust? If it was white or light gray it may be fuel mixture if Black then voltage too high issue.
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Thanks for the reply! I knew I'd hear from you, your the master when it comes to this stuff. How would I go about checking to see if there is oil mixed in with the coolant? I don't have weird colors or smells in the coolant reservoir last time I checked. I'm thinking about a coolant and oil change after work today seeing as I have never flushed the coolant since I have owned the car, just topped it up on rare occasions. As for an oil change.....I'm way overdue, I just figure that because I need to put 2 quarts in a month to compensate for leakage I can extend oil change frequency .
A head gasket is a definite repair in the near future. Oil is leaking from the exhaust side, rearmost part of the head. The front timing chain cover is leaking like crazy as well.....
.A head gasket is a definite repair in the near future. Oil is leaking from the exhaust side, rearmost part of the head. The front timing chain cover is leaking like crazy as well.....
I would definitely flush the coolant because it begins to degrade in efficiency and will turn a horrible color (although you said its fine so not bad in that department). It will also make sure your water pump's life is extended as much as possible. Make sure to use Zerex G-05. You can find it at any local NAPA store if they have it in your state, or alternatively go to the dealership -- their prices are not far off anybody else s when it comes to fluids.
Are you sure the oil leak at the exhaust side isn't coming from the valve cover gasket?
If you are ready for an oil change, you definitely want to make sure to get diesel grade oil. I have "heard" as well that it leaks less than a comparable non-diesel oil. So it may help you in that department. I have a list of good ones in the DIY sticky 2nd page. And also a proper german filter too
Last edited by ps2cho; Oct 22, 2009 at 03:57 PM.
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MBWorld Fanatic!
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From: Connecticut, New Haven
95' AMG SeeThreeSix
It's hard to really tell as the color darkened as I made my way to the back but overall it was a grayish crust buildup. I use 93 octane, could I still be detonating? Possible that I should grab a new 02 sensor just for the heck of it?
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Thread Starter
MBWorld Fanatic!
Joined: Feb 2007
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From: Connecticut, New Haven
95' AMG SeeThreeSix
Far from a master at age 21...but just based on what I have read across forums and experienced between my 2 cars. Oil will rise to the surface if its in the coolant, so it should be obvious in the reservoir.
I would definitely flush the coolant because it begins to degrade in efficiency and will turn a horrible color (although you said its fine so not bad in that department). It will also make sure your water pump's life is extended as much as possible. Make sure to use Zerex G-05. You can find it at any local NAPA store if they have it in your state, or alternatively go to the dealership -- their prices are not far off anybody else s when it comes to fluids.
Are you sure the oil leak at the exhaust side isn't coming from the valve cover gasket?
If you are ready for an oil change, you definitely want to make sure to get diesel grade oil. I have "heard" as well that it leaks less than a comparable non-diesel oil. So it may help you in that department. I have a list of good ones in the DIY sticky 2nd page. And also a proper german filter too
I would definitely flush the coolant because it begins to degrade in efficiency and will turn a horrible color (although you said its fine so not bad in that department). It will also make sure your water pump's life is extended as much as possible. Make sure to use Zerex G-05. You can find it at any local NAPA store if they have it in your state, or alternatively go to the dealership -- their prices are not far off anybody else s when it comes to fluids.
Are you sure the oil leak at the exhaust side isn't coming from the valve cover gasket?
If you are ready for an oil change, you definitely want to make sure to get diesel grade oil. I have "heard" as well that it leaks less than a comparable non-diesel oil. So it may help you in that department. I have a list of good ones in the DIY sticky 2nd page. And also a proper german filter too
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Ohh yeah, the Napa crew down the street knows me well! What weight and brand of diesel motor oil would you recommend for the winter here in New England? That sounds good to me if it will help slow the leak. Pretty sure the leak isn't coming from the valve cover, I'll take a closer look in a bit just to verify. Thanks for the tips man!
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From: Connecticut, New Haven
95' AMG SeeThreeSix
Thanks man, I'll look for some diesel grade stuff, I would assume its much more hardy than general use gasoline engine oil.
Here are some shots of the rear of the engine in which a good amount of oil can be seen dripping down just underneath the rear exhuast manifold, seems to be where the head and block meet? Also a picture of the famous timing chain cover leak!
Here are some shots of the rear of the engine in which a good amount of oil can be seen dripping down just underneath the rear exhuast manifold, seems to be where the head and block meet? Also a picture of the famous timing chain cover leak!
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From: Orland Park, Illinois
1994 E320 (current)
If you are running rich it won't matter what octane you are running it is putting too much fuel in the mixture. you don't necessarily need to put a new O2 sensor in just keep in mind that you may have been running rich. What i would do is monitor you plugs and see what happens. If in 3 or 4 weeks the plugs are collecting the same gray soot then you should start trying to diagnose if it is a mixture issue. It may not be the O2 that is screwing stuff up.
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After taking a second look at that picture, I'm not too sure the timing cover is leaking. In my experience it has always gone down the side of the metal timing cover on the lower half of the engine and I don't see that on yours.
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From: Connecticut, New Haven
95' AMG SeeThreeSix
What would be your next best guess? HG?
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Thread Starter
MBWorld Fanatic!
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From: Connecticut, New Haven
95' AMG SeeThreeSix
If you are running rich it won't matter what octane you are running it is putting too much fuel in the mixture. you don't necessarily need to put a new O2 sensor in just keep in mind that you may have been running rich. What i would do is monitor you plugs and see what happens. If in 3 or 4 weeks the plugs are collecting the same gray soot then you should start trying to diagnose if it is a mixture issue. It may not be the O2 that is screwing stuff up.
This plug has ash deposits which are light brownish deposits that are encrusted to the ground and/or center electrode. This situation is caused by the type of oil used and adding a fuel additive. This condition will cause a misfire. This can be also caused by changing oils in midstream.
Also before, when I was running Bosch resistor plugs (ALWAYS with 93 or 91 octane) and I was detonating very badly. On almost all of them the porcelin surrounding the electrode was completley GONE, cracked off. So I most likley have bits and pieces bouncing around in there still.
Excessive detonation has caused the porcelin on this plug to break away. If this engine is allowed to run, engine damage can occur. Make sure the fuel octane is high enough for the engines requirements.
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Here is a pic from my 260E....I couldn't find a before picture, but I cleaned up that area so I could tell if I was leaking or not.
That is the direction the oil travels if it is leaking. It shouldn't be splattering all the way to the back of the block in the quantities yours shows.
That is the direction the oil travels if it is leaking. It shouldn't be splattering all the way to the back of the block in the quantities yours shows.
