Engine misfire, burning lots of oil
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2005 E320
Engine misfire, burning lots of oil
I have a 2005 E320 with 110k miles that I recently just took on a trip for about 1000 miles. I've noticed some misfire a little bit in the past, but nothing to concern me. I'd just kill the engine and start it up again and it was fine. Ended up having to drive 300 miles with only 5 cylinders running and limped my way back to NC. Throughout my trip I burned 8(!) quarts of oil, and I'm not sure what is the problem. Also not sure if the misfires and oil burning is linked. Oil isnt leaking, its burning for sure. I was thinking it could be either valves or piston rings, surely its not just bad plugs? Don't really know what to do with it right now, just wondering if anyone else knows anything about this. Thank you in advance for any responses!
Additional info
misfire on cylinder 1, 2, and 5 (not all at the same time, just observed during the trip)
usually burns a bit of oil on a cold start, which makes me think its valves
Additional info
misfire on cylinder 1, 2, and 5 (not all at the same time, just observed during the trip)
usually burns a bit of oil on a cold start, which makes me think its valves
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From: DC Metro Area
2007 Mercedes E550
I have a 2005 E320 with 110k miles that I recently just took on a trip for about 1000 miles. I've noticed some misfire a little bit in the past, but nothing to concern me. I'd just kill the engine and start it up again and it was fine. Ended up having to drive 300 miles with only 5 cylinders running and limped my way back to NC. Throughout my trip I burned 8(!) quarts of oil, and I'm not sure what is the problem. Also not sure if the misfires and oil burning is linked. Oil isnt leaking, its burning for sure. I was thinking it could be either valves or piston rings, surely its not just bad plugs? Don't really know what to do with it right now, just wondering if anyone else knows anything about this. Thank you in advance for any responses!
Additional info
misfire on cylinder 1, 2, and 5 (not all at the same time, just observed during the trip)
usually burns a bit of oil on a cold start, which makes me think its valves
Additional info
misfire on cylinder 1, 2, and 5 (not all at the same time, just observed during the trip)
usually burns a bit of oil on a cold start, which makes me think its valves
Thread Starter
Newbie
Joined: Feb 2017
Posts: 9
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2005 E320
Thread Starter
Newbie
Joined: Feb 2017
Posts: 9
Likes: 0
2005 E320
Sorry if my wording was misleading, I burned 8 quarts in 1000 miles, I drove 300 miles with engine misfires. Still, not good. I appreciate the help.
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From: Richmond, CA
2001 E320 Wagon, 2006 LBZ Silverado, 2007 E63 (sold), 2001 E55 (sold)
Burning 8 quarts in 1000 miles is damn near as bad as doing it in 300. I wouldn't be driving the car at that point until I got **** figured out.
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MBWorld Fanatic!
Joined: Aug 2015
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From: DC Metro Area
2007 Mercedes E550
You also might check if wires/coils are properly connected and look ok.
That's what I would do.
In terms of the p0160, isn't that your FRONT Oxygen Sensor??!!
IF so, that means you air-fuel ratio could be messed up, and that is a big deal.
First change the plugs, won't hurt anything and you'll get better performance either way.
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Junior Member
Joined: Aug 2017
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From: Dallas, Tx
2008 E350
You either have a blown head gaskets, bad rings, or a number of any other serious issues. Tell tale sign is you burned 8 quarts of oil over 1000 miles...Unfortunately your issue is not a simple one (like bad plugs). Do not drive the car anymore, driving with a serious misfire can destroy your catalytic converters..hopefully you haven't already.
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From: DC Metro Area
2007 Mercedes E550
You either have a blown head gaskets, bad rings, or a number of any other serious issues. Tell tale sign is you burned 8 quarts of oil over 1000 miles...Unfortunately your issue is not a simple one (like bad plugs). Do not drive the car anymore, driving with a serious misfire can destroy your catalytic converters..hopefully you haven't already.
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From: V E G A S
1922 Ford Model T / no OBD
Frankly - chances of 6 (!) spark plugs going bad at the same time are slim. Beside - plugs in those engine run for 150k just fine.
So my suggestion is to do compression test when changing the plugs and pray for the best.
O2 sensor is important in the system as well, so when compressions test acceptable, get on it before driving.
So my suggestion is to do compression test when changing the plugs and pray for the best.
O2 sensor is important in the system as well, so when compressions test acceptable, get on it before driving.
Last edited by kajtek1; Nov 29, 2017 at 01:03 PM.
Thread Starter
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2005 E320
****. this might be the end for my E320. Took it to my mechanic this morning and he will test compression and change plugs etc. Seems odd, one of the reasons I bought this car is because of how durable the engines are. Seems like I have a very uncommon problem. I'll keep you guys posted, and thanks again for all the help.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
You either have a blown head gaskets, bad rings, or a number of any other serious issues. Tell tale sign is you burned 8 quarts of oil over 1000 miles...Unfortunately your issue is not a simple one (like bad plugs). Do not drive the car anymore, driving with a serious misfire can destroy your catalytic converters..hopefully you haven't already.
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From: V E G A S
1922 Ford Model T / no OBD
Engine makes about 2250 turns per mile x 1000 miles makes 2,250,000 turns for the trip.
So 8l divided by 2 250 000 makes 0.0000035 l per turn. or 0.0035 ml per turn.
1 drop is 0.05 ml, so we are talking 1/12 of drop per turn, assuming all the used oil goes into single cylinder. Far away from amount that would hydrolock
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2005 E320
Just got word from my mechanic. He pulled the plugs I had misfires on and the previous owner had gotten plugs of the wrong spec installed. Also found out that each cylinder has 2 plugs, so a complete replacement of all 12 plugs will be done. He also told me that the plugs could be sticking -- something I didn't even consider which would cause a huge amount of oil to burn. I guess if all 6 cylinders had shot plugs and were causing misfires, the pistons stick and oil just flows right in. After the plugs are replaced I'll update again. Also, My_E350, if it was a blown head gasket, would that mean that oil is leaking out the side and running down the exterior of the engine, or would it still be internal? I quickly peeked at it before I brought it in because i considered gasket but I didn't see anything. Thanks again for all you help guys, super great.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
"The plugs could be sticking"
What does that even mean? There's no moving parts on a spark plug. How could even a plug that isn't firing "cause a huge amount of oil to burn"? How could pistons "stick" with the engine turning and not result in a dramatic engine failure?
What am I missing here? It'd be great if a dozen plugs solved all your problems, but you've completely lost me with what your mechanic has told you.
What does that even mean? There's no moving parts on a spark plug. How could even a plug that isn't firing "cause a huge amount of oil to burn"? How could pistons "stick" with the engine turning and not result in a dramatic engine failure?
What am I missing here? It'd be great if a dozen plugs solved all your problems, but you've completely lost me with what your mechanic has told you.
Thread Starter
Newbie
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2005 E320
"The plugs could be sticking"
What does that even mean? There's no moving parts on a spark plug. How could even a plug that isn't firing "cause a huge amount of oil to burn"? How could pistons "stick" with the engine turning and not result in a dramatic engine failure?
What am I missing here? It'd be great if a dozen plugs solved all your problems, but you've completely lost me with what your mechanic has told you.
What does that even mean? There's no moving parts on a spark plug. How could even a plug that isn't firing "cause a huge amount of oil to burn"? How could pistons "stick" with the engine turning and not result in a dramatic engine failure?
What am I missing here? It'd be great if a dozen plugs solved all your problems, but you've completely lost me with what your mechanic has told you.
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
A ring sticking is unusual. A few cylinders with rings sticking is... REALLY unusual. Unless the car was abused or not at all maintained.
Snarky question, I know, but do you regularly spend time at the red line on the tach?
Snarky question, I know, but do you regularly spend time at the red line on the tach?
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2005 E320
No, I don't. Problem is I got the car at 105k miles, and have no history on previous work done or anything like that. Considering the previous owner put wrong spec plugs in, I don't think maintenance was their primary focus.
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From: V E G A S
1922 Ford Model T / no OBD
It is more likely dealer put overstock plugs, just like they put wrong oil to few Bluetec - costing them to seize.
I don't think the owner would do something like it as plugs are cheap but labor takes time.
I have not see sticky ring in my life, so will wait for final diagnosis.
I don't think the owner would do something like it as plugs are cheap but labor takes time.
I have not see sticky ring in my life, so will wait for final diagnosis.
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From: s.f. bay area
s500 GL450 GL63 Z71XL Yukon 67 396 SS velle 68 Vert Camaro 69 RSSS Vert Camaro 75 Blazer
Just got word from my mechanic. He pulled the plugs I had misfires on and the previous owner had gotten plugs of the wrong spec installed. Also found out that each cylinder has 2 plugs, so a complete replacement of all 12 plugs will be done. He also told me that the plugs could be sticking -- something I didn't even consider which would cause a huge amount of oil to burn. I guess if all 6 cylinders had shot plugs and were causing misfires, the pistons stick and oil just flows right in. After the plugs are replaced I'll update again. Also, My_E350, if it was a blown head gasket, would that mean that oil is leaking out the side and running down the exterior of the engine, or would it still be internal? I quickly peeked at it before I brought it in because i considered gasket but I didn't see anything. Thanks again for all you help guys, super great.
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2005 E320
Congratulations on whoever said it, rings were the culprit. Rings need to be redone on one cylinder, along with a scored piston. That will be replaced and rings will be redone. Better than a lot of things, but still not cheap. Thanks again for all of your advice everyone, I really appreciate it.
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Joined: Apr 2007
Posts: 633
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From: USA
2006 E320 CDI
Would have been helpful to see pictures of the plugs, unusual to have a scored piston, you sure it wasnt cylinder wall scored? Anyone, anyone are there really two spark plugs in each cylinder? I have none in mine 
air craft engines have two plugs per cylinder.
air craft engines have two plugs per cylinder. 
