Fletcher5051

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

rapidoxidation

How do you know which cylinders are misfiring? Got codes you can share? What do the spark plugs look like?

LexBrett2

codes codes codes must get the codes

Fletcher5051

Sorry, how could I forget

P0301
P0302
P0305
P0300
and likely unrelated but P0160

Havent had a chance to check plugs yet, that’s what i’ll do as soon as i get some free time

Ward83

8 quarts of oil in 300 miles indicates a severe problem. I'd run a compression check on all cylinders, it sounds like either a bad head gasket or piston ring.

Fletcher5051

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.

Strigoi

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.

LexBrett2

It is highly likely that all you need to do is change the plugs.
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.

My_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.

LexBrett2

Yeah I skimmed over the issue about the oil... too bad it is not the plugs.

kajtek1

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.

Fletcher5051

****. 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.

rapidoxidation

Ya, I'm kinda thinking that if that much oil is coming into the cylinders there's a real chance of hydrolocking the engine (and bending some rods) at the next startup.

kajtek1

Quick calculation.
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

Fletcher5051

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.

rapidoxidation

"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.

Fletcher5051

Sorry, im dumb and typed that up pretty hastily and made some typos. Completely referring to piston rings sticking. Honestly never heard of that happening in a car like this so I'm a little confused but it will likely mean rings need to be redone.

kajtek1

If you are not too technical - ask mechanic about diagnosis in writing with codes listed. This way we can analyze that without making translation errors.

rapidoxidation

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?

Fletcher5051

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.

kajtek1

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.

angelglo

You need a new mechanic. If the mechanic knew what he was doing, he would have been able to give you a better diagnosis. A answer like, "the rings could be sticking" doesn't tell you anything. Its basically saying, it could be the rings, valves, blown head gasket. You should ask for the codes and if he did a leak down on it. Even if he did a compression test the right way would tell you if it was the rings or the valves. Did he tell you what the plugs looked like in each cylinder? You will get more issues down the road ie, O2 sensor, Catalytic issues, engine failure.

Fletcher5051

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.

ot1