ML270 white smoke and cuts off

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Dmitrii

New Member
Joined
Sep 12, 2015
Messages
4
Car
ML270
Hi everyone,

I am wondering if someone had a similar problem. With no previous signs my 2001 ML270 suddenly cuts off on the highway. (It had no signs of any problems before). A few attempts starting the engine it starts, but had no power at all, I managed to get to safe place, but it heavily smokes with white-grey smoke. Diagnostics shows a few stored faults but only one current: "P0100 Hot film MAF sensor (B2/5) Supply voltage problem (too low)". I already ordered it, but it looks like it is not the only problem, cause according to a few posts here even if it is disconnected car suppose to drive on lower power. In my case it is pretty much impossible.

What makes me additionally suspicious that it is not the only MAF sensor is that the car has never make any smoke before. Exhausts gases were always pretty transparent.

I have already bought MAF, but it takes about 2-3 weeks for it to get to Australia. I am wondering if any suggestion what should be checked more, in order not to waste to much time in waiting for consequent postages.

After careful inspection I found that a vacuum pump makes strange grinding noise(it is different from normal). It is especially noticeable when engine just stopped. Could it be an additional problem?

Could anyone give some advice which part should be tested, please? :dk:
 
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Bit of a long shot, but the grinding noise you describe might be from a failed 'free-wheeling' pulley fitted to the alternator, as a result you might be low on voltage at the battery causing the supply voltage problem?

To check the pulley, remove the drive belt and inspect it, it should revolve freely one way but lock/drive the alternator the other way.

Edit... With the engine running, see what voltage you are getting at the battery, you should be seeing circa 14v plus
 
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Would be courteous to let us know any progress?
 
Thank you for an answer. Yesterday I tried to check EGR unit(I found description in the previous topics on the forum). Assembling disassembling shows that EGR wasn't working properly, but it is not the main problem. It is closed most of the time and opens less then suppose to open. It also suck in air, which I suppose could be the cause of grinding noise from vacuum. Anyway, cleaning and checking EGR didn't help to fix the main problem with engine.
I didn't measure voltage, because I bought multimeter late yesterday, it was to dark outside to try to do anything. Anyway, my attempts discharged battery, consequently it will take a while to charge it and check electrical circuits in the proper conditions.
I will write here about the progress as soon as I'll have more information.
I also bought an OBD2 error codes scanner (Vgate Scan) which appears to be incompatible with ML270. Could anyone advice some error coder reader which works properly for ML270, please?
 
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Check turbo,if turbine(fan)got play in it then turbo is gone and symptoms are also showing like turbo should be looked at
 
And check engine oil befor starting the ml as you must be loosing oil via turbo seals,let me know
 
Turbine was the first place which I tried to check, but it looks right, it doesn't play and rotates by finger easily. I also started the car with air hose(for a few seconds), it rotates inside when engine is running. Apparently I was unable to check if the speed is appropriate, but works somehow. By the way, when I disconnected an air hose I noticed that inside of it surface is a bit wet of oil(not much but it is there, MAF also a bit covered in tiny oil droplets). Not sure if it supposed to be like this or it is a sign of the problem or a normal state. According to some videos online it is kind of fine. at least the same amount present in a few videos and there it was considered normal.

One more argument which makes me think that it is not a turbine is that the problem appears suddenly, with no previous signs of any problem. If it would be a gasket in turbine it probably would be increase of smog in the exhaust over time.(Not sure if it is true, but it looks like a reasonable assumption)

One more thing which I noticed is that when car just starts smog is white, but in a few seconds it become darked. It looks like it is using off air somewhere inside... I haven't changed air filter yet. Probably it will be the next part which I will change. But it is still sounds wired cause it appears way too fast...
 
Hi everyone,

After some additional tests of turbine and air filter and a few other stuff it looks like there are little chances that problem is somewhere on the surface... Also considering that the car cuts off on acceleration, I suppose it could be possible that timing chain slipped off. I am not sure if it could be the problem. I also tried to run engine with and it makes some noise on above 1000 RPM.
Could someone tell if it could be the problem? If yes, is it possible that it affected something else when it was running with wrong positions of timing chain? How complicated could it be to replace chain? Is there any way to check it without disassembling engine head?
Thank you in advance!
 
Hi everyone,

After some additional tests of turbine and air filter and a few other stuff
it looks like there are little chances that problem is somewhere on the surface...

Also considering that the car cuts off on acceleration,

Check this link from the stickies section >> http://www.mbclub.co.uk/forums/engine/144927-lack-power-cdi-what-do.html

Also

You may have a faulty injector/s dumping the fuel rail pressure under load.
That's the cutting out part.

The white smoke is the unburnt diesel from the faulty injector/s exiting the engine.

Get a MB Star session arranged and check the fuel delivery system.
 
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