ml 270 cdi oil leak from inlet manifold w163

thebeard

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Hi All

My 2003 ML 270 CDI apparently has an oil leak from the inlet manifold
I’ve just got back from MB dealer in Bromley.
And they say it’ll cost £1,700 to replace the inlet manifold!
Apparently fuel pipes would also need to be replaced a major job!
I asked how is oil leaking from the manifold?
And apparently there are oil galleries in the manifold? WHY???
Manifold is plastic! I knew Mercedes were going cheap but this is madness. Plastic!

Has anyone else experienced this?

Any info welcome.

Cheers.
 

Alex Crow

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what caused you to have it investigated in the first place, or was it just discovered through routine servicing?

the oil is circulating through the intake system from the engine breather. there are no oil galleries in your manifold.

oil leaking from the manifold is associated with failed inlet port shut-off flaps (don`t ask, really, don`t!!), you may have also noticed a `whooshing` noise under load. it sounds likely your vehicle does need a new manifold, but fuel pipes should be fine and £1700 is way steep. trust the work to a good independant who has done this fiddly but straightforward job before. also consider a complete manifold with m55 shut off motor and egr valve fitted, this is part of what MB are quoting for.
 

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what caused you to have it investigated in the first place, or was it just discovered through routine servicing?

the oil is circulating through the intake system from the engine breather. there are no oil galleries in your manifold.

oil leaking from the manifold is associated with failed inlet port shut-off flaps (don`t ask, really, don`t!!), you may have also noticed a `whooshing` noise under load. it sounds likely your vehicle does need a new manifold, but fuel pipes should be fine and £1700 is way steep. trust the work to a good independant who has done this fiddly but straightforward job before. also consider a complete manifold with m55 shut off motor and egr valve fitted, this is part of what MB are quoting for.

Thank you,, Have you just dropped in from" paradise " its so good having you on board :D:D;)
 
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thebeard

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what caused you to have it investigated in the first place, or was it just discovered through routine servicing?

the oil is circulating through the intake system from the engine breather. there are no oil galleries in your manifold.

oil leaking from the manifold is associated with failed inlet port shut-off flaps (don`t ask, really, don`t!!), you may have also noticed a `whooshing` noise under load. it sounds likely your vehicle does need a new manifold, but fuel pipes should be fine and £1700 is way steep. trust the work to a good independant who has done this fiddly but straightforward job before. also consider a complete manifold with m55 shut off motor and egr valve fitted, this is part of what MB are quoting for.


Hi alexander thanks for your post.

I discovered oil drops on my drive and on the road where I also park.
My ML has done just 37,000 miles and I was surprised to hear the manifold is leaking oil.

The MB technician mentioned the shut-off flaps.

I don’t get a whooshing noise.
Did you mean if I get a whooshing noise under load then it sounds like I need a new manifold?

The oil drips appear to have slowed, I’m going to keep an eye on it.
I guess it’s not a major leak problem so I will carry on just parking on the road and see how it goes.

About a month ago I had to replace the Air mass sensor, the inlet hose had blown off I lost power etc and it stopped working so I bought another and replaced it myself after MB dealer said it could be the air mass sensor.
They wanted it back over night to do further investigation. But I was too busy and needed the car so I just bought a new one and fitted it and hey presto all back to normal, I hate to think how much they would have charged me.

I think there is an element of MB making up work to make the money and this manifold leak could be the same.

I’m going to have a look at a friend’s garage tomorrow get it on a ramp.

Any other tips on this?
 

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Agree with A/P,

A lot of oil leaks come out the top boost pressure pipe joint!

easy to spot as its at the front of the engine to the right as you look at it!!
 

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just wondered if there is a cure for the oil get into the intake systems I know you will get a little bit but is there something you can do to stop lots going in? replace the breather valve/oil separater?
 

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Hi alexander thanks for your post.

I discovered oil drops on my drive and on the road where I also park.
My ML has done just 37,000 miles and I was surprised to hear the manifold is leaking oil.

The MB technician mentioned the shut-off flaps.

I don’t get a whooshing noise.
Did you mean if I get a whooshing noise under load then it sounds like I need a new manifold?

The oil drips appear to have slowed, I’m going to keep an eye on it.
I guess it’s not a major leak problem so I will carry on just parking on the road and see how it goes.

About a month ago I had to replace the Air mass sensor, the inlet hose had blown off I lost power etc and it stopped working so I bought another and replaced it myself after MB dealer said it could be the air mass sensor.
They wanted it back over night to do further investigation. But I was too busy and needed the car so I just bought a new one and fitted it and hey presto all back to normal, I hate to think how much they would have charged me.

I think there is an element of MB making up work to make the money and this manifold leak could be the same.

I’m going to have a look at a friend’s garage tomorrow get it on a ramp.

Any other tips on this?

i mentioned the `whooshing` as often this is the first thing people notice when the manifolds start to leak - the noise is boost pressure escaping.

if you do get the car in the workshop, inspect the underside of the manifold at the cylinder head side. you will see a metal rod connecting 5x short plastic levers and a servo motor and link. check that all the levers are connected and move freely. when blipping the throttle at idle you should see the linkage/levers move to and fro.

on close inspection you may see levers hanging loose or lower than others and oil dripping from where they join the manifold. if so then i strongly recommend replacing the manifold as there are plastic shut off flaps located in the inlet ports which can come completely loose and get caught in the valves. i have not yet known one bend a valve (with help from the piston), but it is only a matter of time.

you will find it difficult to easily see all this but a strong light and well placed mirror will help. we now have a snap-on endoscope which is fantastic for these jobs.

as for MB fleecing you, some will and some won`t. i know a main dealer tech guy who is straight as a die and a genius to boot, but his service advisors are another matter...............

why the shut off flaps? i can`t be sure, wis net will have a description, but my guess is it is all to do with promoting swirl in the combustion chamber to homogenise the exhaust gas (from egr valve) and intake air at part or closed throttle. at higher throttle the egr would be closed and the flaps open to maximise cylinder filling, perhaps.
 

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just googled it and found this blurb for the new generation diesels.

"Intake port shut-off for optimum air supply"

"The combustion air subsequently flows into the charge-air distributor module, which supplies air to each cylinder in a uniform manner. Built into the distributor module is an electrically controlled intake port shut-off which allows the cross-sectional area of each cylinder's intake port to be smoothly reduced in size. This alters the swirl of the combustion air in such a way as to guarantee that the charge movement in the cylinders is set for optimum combustion and exhaust emissions over the full spectrum of engine loads and rev speeds."
 

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just googled it and found this blurb for the new generation diesels.

"Intake port shut-off for optimum air supply"

"The combustion air subsequently flows into the charge-air distributor module, which supplies air to each cylinder in a uniform manner. Built into the distributor module is an electrically controlled intake port shut-off which allows the cross-sectional area of each cylinder's intake port to be smoothly reduced in size. This alters the swirl of the combustion air in such a way as to guarantee that the charge movement in the cylinders is set for optimum combustion and exhaust emissions over the full spectrum of engine loads and rev speeds."

This would also fit in to the new petrol engines being designed. there is no vacuum and runs like a diesel, and the flaps can control the mixture taking it down to the leanest burn possible something like 14 to 1 if I remember,,and getting 4 to 5 sparks per stroke. The same engine had no running gear,,all of the valves were controlled by solenoids
 
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thebeard

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Thanks for the info guys.


Update.

I didn't get a chance to get the ML on a ramp before going on hols to France.
Whilst in France I jet washed the underside where the oil had built up on the cross member under the engine so I could see if it was still leaking oil. "they have great jet washes out there hot and powerfull excellent!"

So far ZERO oil, not a drop!

I can only think that the leak was down to the top boost pressure pipe coming off and the few miles i did before it was reconnected oil must have blown over the engine, when I had that problem.

So fingers crossed I'm going to keep an eye on it but so far so good it's been a month and no sign of any oil on the cross member or new spots on the drive.
 

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Agree with A/P,

A lot of oil leaks come out the top boost pressure pipe joint!

easy to spot as its at the front of the engine to the right as you look at it!!

Hi everyone, i've got the same problem, do i need to change the boost pressure pipe as well as the inlet manifold? !!!!HELP!!!! please.
 
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thebeard

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I wanted to post an update to my oil leak problem. Since 28 July 2009 my first post I’ve had a Major development, which may help others reading this thread.

Since my initial oil leak problem on 28 July 2009 until Last Friday 04 FEB 2011.
I have just lived with the oil leak as I have said above I cleaned the oil from the sub frame every so as I was mistaken about the oil being overfilling as it continued to leak but very very little so I didn’t worry.

Anyhow last Friday I got a warning light come up and the ML went into limp home mode i.e. no Turbo.
So I took it back to Mercedes Bromley to get a diagnosis.
Diagnosis fuse was blowing due to oil in the inlet manifold stepper motor.

The oil in the manifold was not a surprise, as I knew there was an oil leak.
What was a BIG surprise was their diagnosis of the cause of the oil leak!!!!!
Unlike the previous diagnosis see my first post above 28 07 2001 04:53 PM
This time the Cause was diagnosed as the oil separator.
The cure is to
Clean away all the oil.
1. Replace the oil separator
2. As it’s now knackered replace the stepper motor.

I am absolutely furious!!!!!
It now appears the initial diagnosis that’s the £1,700 number was utter nonsense!!!
All that was necessary was 1. To change the oil separator!!!!!!

But now I’m also having 2. Replace the stepper motor.

I am particularly angry as the Mercedes Bromley technician / mechanic back in 2009 gave me a load of bull about fuel lines into the inlet manifold “there are no fuel lines going into the manifold!” together with other nonsense about oil galleries in the inlet manifold.
I’m totally disgusted!!!!!
It’s now 18 months since the first incorrect diagnosis and bull I was given.
I’ve no way of getting any resolution from Mercedes Bromley for them to pay for the extra cost of the replacement of the stepper motor.

Oil leaks only occur in the inlet manifold if too much oil enters the closed loop of dirty air circulating to be re-burnt and that will be due to a knackered oil separator.
Conclusion
Don’t trust main dealers to correctly diagnose, which is very worrying.
The technician could have been incompetent but this is pretty simple to me especially given the all bull I was given. I believe I was being scam’d for more work!
I hope others avoid my problem in needing to replace the stepper motor or manifold.

So Finally after my rant…

Conclusion on the Problem
Anyone experiencing oil leaking from the inlet manifold.
I would recommend checking the oil separator before looking further.
 
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Jdokal

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What does the oil separator look like?
 

oigle

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I wanted to post an update to my oil leak problem. Since 28 July 2009 my first post I’ve had a Major development, which may help others reading this thread.

Since my initial oil leak problem on 28 July 2009 until Last Friday 04 FEB 2011.
I have just lived with the oil leak as I have said above I cleaned the oil from the sub frame every so as I was mistaken about the oil being overfilling as it continued to leak but very very little so I didn’t worry.

Anyhow last Friday I got a warning light come up and the ML went into limp home mode i.e. no Turbo.
So I took it back to Mercedes Bromley to get a diagnosis.
Diagnosis fuse was blowing due to oil in the inlet manifold stepper motor.

The oil in the manifold was not a surprise, as I knew there was an oil leak.
What was a BIG surprise was their diagnosis of the cause of the oil leak!!!!!
Unlike the previous diagnosis see my first post above 28 07 2001 04:53 PM
This time the Cause was diagnosed as the oil separator.
The cure is to
Clean away all the oil.
1. Replace the oil separator
2. As it’s now knackered replace the stepper motor.

I am absolutely furious!!!!!
It now appears the initial diagnosis that’s the £1,700 number was utter nonsense!!!
All that was necessary was 1. To change the oil separator!!!!!!

But now I’m also having 2. Replace the stepper motor.

I am particularly angry as the Mercedes Bromley technician / mechanic back in 2009 gave me a load of bull about fuel lines into the inlet manifold “there are no fuel lines going into the manifold!” together with other nonsense about oil galleries in the inlet manifold.
I’m totally disgusted!!!!!
It’s now 18 months since the first incorrect diagnosis and bull I was given.
I’ve no way of getting any resolution from Mercedes Bromley for them to pay for the extra cost of the replacement of the stepper motor.

Oil leaks only occur in the inlet manifold if too much oil enters the closed loop of dirty air circulating to be re-burnt and that will be due to a knackered oil separator.Conclusion
Don’t trust main dealers to correctly diagnose, which is very worrying.
The technician could have been incompetent but this is pretty simple to me especially given the all bull I was given. I believe I was being scam’d for more work!
I hope others avoid my problem in needing to replace the stepper motor or manifold.

So Finally after my rant…

Conclusion on the Problem
Anyone experiencing oil leaking from the inlet manifold.
I would recommend checking the oil separator before looking further.

I wouldn't be too sure about that, if I were you. Comments by Alexander and others re flaps etc are very pertinent. There are a couple of threads about choked inlet manifolds on ML270 and disabling the EGR that you might like to read. Covers the issue well. Might save you a pound or three down the track too.
 
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thebeard

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Thanks I've read those threads and my symptoms are a little different.

My EGR is clear and the flaps don't stick there is visible oil around the oil separator outlet.
My 2003 ML has covered just 47,000 miles.


My Indi has another option If my oil leak continues if it's not the oil separator. "Mercedes are now sure it is the oil separator."
Disconnect the stepper motor "stopping the fuse blowing and then program it out so no error code appears. This would stop the motor working does anyone see a problem with doing that?
 

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Thanks I've read those threads and my symptoms are a little different.

My EGR is clear and the flaps don't stick there is visible oil around the oil separator outlet.
My 2003 ML has covered just 47,000 miles.


My Indi has another option If my oil leak continues if it's not the oil separator. "Mercedes are now sure it is the oil separator."
Disconnect the stepper motor "stopping the fuse blowing and then program it out so no error code appears. This would stop the motor working does anyone see a problem with doing that?

Provided the flaps are set in the open position, that should be fine. Didn't know such programming could be done.
 

Alex Crow

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i don't believe anyone does a 'remap' for running without the stepper motor - without some kind of software change in the ecu you will be in permanent 'limp home' with the M55 stepper motor disconnected.

also, how do you suppose the oil has got onto the stepper motor? the manifold is not supposed to leak even a drop, and there will ALWAYS be a quantity of engine oil circulating in the inlet sytem whether the seperator is OK or not.
 

Colin_P

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Does anyone know to test one of those stepper motors? Mine was swapped a while back, and I have cause to believe that there may have been nothing wrong with it. The old one's gathering dust on a shelf somewhere at home.
I don't feel like swapping them, as it looks like it might be a fiddly job.
 

Alex Crow

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Does anyone know to test one of those stepper motors? Mine was swapped a while back, and I have cause to believe that there may have been nothing wrong with it. The old one's gathering dust on a shelf somewhere at home.
I don't feel like swapping them, as it looks like it might be a fiddly job.

it is not going to be easy to test, it has integrated logic circuitry inside and is much more than just a motor. what symptoms did you have that required its replacement? why do you believe it was not faulty?
 


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