I have a Mercedes ML350 that has 122000 miles and smokes intermittantly, any suggestions?
Country: United StatesMake: Mercedes-BenzModel: ML350Year: 2005
changed oil, new spark plugs, cleaned valve covers and oil passages
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What color is the smoke.
Okay, is the check engine light on?
No, it doesn't smoke all the time, but when it does it emits a huge cloud, enough to create a smoke screen behind me
Under what circumstances does this happen?
Accelerating from a stop? When the engine is cold/warm?
Do you feel a loss of power when it starts smoking?
normal driving, sometimes on acceleration, rarely on start up, and when it is warm, a little loss in power
Very strange behavior for the symptom. It leads me to believe there is a problem with fuel metering. However, that should set a code and light the check engine light.
When it does smoke, it usually uses about a1/2 litre of oil
Okay, so we know it is oil smoke then?
That is typically blue in color more than grey.
I took a 200 mile trip, and it used 6 litres of oil,
What is the service history like on this vehicle? Has it been well cared for?
Okay, that is a good tidbit of information to have.
That's what I thought, but it is more grey, not white or black, I could be off in color, my wife says i am not good at colors
I was going to suggest a higher viscosity oil, but I don't think that will touch such vast consumption.
I don't know about the service history, just got it.
Its okay, I'm not good with colors either.
Since I got it, i have been changing the filter about once a month and it is usually pretty dirty
I'm afraid what you have described is a severely worn engine.
I suspect that the oil is bypassing the piston rings.
also i have been changing oil every month, I did pay to get it cleaned, and I was afraid you were going to say that!
You certainly need to get an opinion in person as well. I don't want to condemn the engine from my computer.
would a compression check verify that?
Maybe, but because the problem is intermittent, it can only add to the evidence. If it comes back with good compression, that does not mean the engine is solid, just solid when the test was done. If that makes any sense.
What a compression test would look for is a big variance of compression between cylinders and/or low compression across all cylinders.
Ok, it looks like I will be in the market for a used engine
Perhaps. I would suggest finding a reputable independent shop with Mercedes experience for a second opinion and a quote on the repair. Maybe there is something I am overlooking that won't cost you an engine.
I wish you luck in any event. Not much worse than buying a car to find out it needs previously unknown work.
When I changed the plugs, all the plugs on the passenger side were fouled with oil and had excessive white scale, the drivers side was same but not so bad
That's a pretty telling sign too.
Let me know if you have any additional questions.
Anything else before I move on the the next customer?
no that will do it
5+ years spent managing an import auto repair shop specializing in German cars.