2008 Ml320 CDI check engine light
 

I got the following 10 codes on my car.



2527-2 check component Y27/9 (left EGR positioner)
3053-4 check component B2/7b1(intake air temperature sensor)
3052-4 check component B2/6b1 (intake air temperature sensor)
2603-4 check component B2/7 (Right hot film mass air flow sensor)
2602-4 check component B2/6 (left hot film mass air flow sensor).short circuit or open open circuit
2646-1 check component B2/6 (left hot film mass air flow sensor). Value is above limit.
2514-2 check component R39/1 (vent line heater element) short circuit to ground
2679-4 check component B76 (fuel filter water level sensor)
2526-2 test signal cable to component Y77/1 (charge pressure positioner) short circuit to ground
2530-2 check component M55 (Inlet port shutoff motor). short circuit to ground



Dealer says replacement of oil cooler,air intake manifold,etc and the bill is $2,900 + tax. My car is out of warranty and on an after-market warranty but the warranty company simply declined the repair request saying it is not covered. But what is the real problem here? Do I need to have the oil cooler replaced or just the oil motor? One tech even says it may be just the flaps are sealed,etc.



Any one can help here? Really appreciate it.

Also I noticed that when I try to accelerate, the rpm would reach over 3,000 RPM and the speed however picks up slowly.Only at later time the two move in tandem and consistent.

I wonder if this has anything to do with the check engine light?

Find an independent service center to verify. I am leaning toward wiring issue. The variety of items is curious.

That many codes looks like an electrical problem.

Start with checking fuses.

Acceleration sound liker it is "limp" mode.

Thanks guys for your input. What may have caused the limp mode?

If the computer (ECU) believes that some condition could cause damage, it will reduce the power.

I believe common cause is if the ECU thinks their is a problem with the intake control that could allow excessive turbo speed.

Since a bunch of the codes indicate the ECU was not getting good data from input sensors, this fits.

Will take the car to an independent dealer this Friday,based on their opinion (just by seeing the codes),they don`t think replacing the oil cooler is necessary.

I just found this from another post here. Sounds like your issue.

http://www.benzworld.org/forums/w164...ml#post5996393
I want to thank Sid and Skippy for this thread. http://www.benzworld.org/forums/imag...es/bowdown.gif
I had simmilar problem with my ML 320 CDI for couple of months now and the carhttp://images.intellitxt.com/ast/adTypes/icon1.png was in two shops with no luck. Yesterday i was able to find this thread and fix it my self.
The car could not accelerate and had around 10 different codes. The codes were pretty much for all of the sensors on the engine. If you try to erase them they were comming right back on. I went to "Mercedes Benz of Buckhead" in Atlanta and after paying $150 to diagnose the problem they told me that is problem with the harness and i need to pay another $850 to tell me what exactly is. I was told they needed to start dissambleing the front of the car to pin point the bad wires, but most likely i need new harness ($4,000-$5,000). Then i took the car to another service place and sat there for three weeks with no luck.
It turned out to be the problem Sid described. The seal on the turbo was broken and oil was leaking on top of that plug, which shorted and burned the fuse (#104 - 15 amp). I replaced the seal and the fuse and the car is running great once again. It only cost me $15 to fix it and the stealer wanted $5,000. Hopefully this will help others to determine their problem and fix it.http://www.benzworld.org/forums/imag...s/thumbsup.gif

I have 10 codes,e.g.M55,sensors,etc.The repair shop changed the fuse on my 2008 ML320 CDI and after couple of times the fuses being blown out,the fuse finally got settled.But the check engine light popped back on. Is it possible that I have to replace the motor or even the entire oil cooler then? Some tech mentioned the oil leak from one of the lines (I am curious to know how often the oil leak can occur on the lines rather than seals/gaskets?)

A couple of things. First This information is related to a TSB that talks about the gasket from Oil cooler to engine needing to be replaced.
Traces of oil in area of oil cooler (inner V) on engine 642
Topic number LI18.30-P-055434 Version 1 Design group 18.30 Oil cooling system Date 01-14-2013 Validity All passenger car / light truck models with engine 642 Reason for change
Complaint: ^ Traces of oil in area of oil cooler (inner V) on engine 642. ^ Traces of oil at drain points of inner V. Cause:
Seals between engine block and oil cooler may be leaking due to incorrect installation. Remedy:
Replace seals, observe installation instructions. Note:
The oil cooler is not the cause and must not be replaced.

Secondly,

If in fact the oil is leaking from Air Intake and has gotten on the harness, its possible it needs to be cleaned up to fix the conductivity of the harness connections

Also where are located? Someone might be able to recommend a good indy shop.

Thanks. I am in Toronto,Canada. I heard about some shops such as NV Motors,Workshop MB,etc.Not sure if they are good. It looks unlikely the oil is leaking from seals/gasket,otherwise the repair shop designated by my after-market warranty company would let me know (or should?)

I think it may be better to quote some diagnosis from MB dealer at Buffalo.

Fuse 54 in the 58 Fuse Block is blown and needs replacement. The charge air manifold and engine oil cooler are leaking and leaking oil into the fuse block. Charge air intake and oil cooler will need to replaced to prevent from further shorting of the electrical system.The price is around $2,900+tax. What is your thought?

They are charging you dealer prices so it is too much. You can save yourself 1000$ by doing it at independent shop. I have exactly the same car with exactly same problem (less the blown fuse) at my shop now. You are welcome to come over and see how it gets done :)

Igor.

Hi,Igor,

Do you mean it would cost $1,900 to fix the problem? Thx.

At most. That oil cooler gasket job is 1250$ (parts included), add the fuse...

Igor.

Hi, just heard back from the indy shop and the actuator motor needs replacement,not oil cooler. The quote is $1,590+tax.

Igor,what is your thought?

Did the oil come from a dripping intake seal on the Turbocharger?

Turbo inlet seal leaks are common. If unattended to, it drips down into the harness case under the throttle and shorts out the swirl motor.

Best fix, replace the turbo inlet seal, replace the swirl motor, clean or replace the intake manifolds, and yes while your at it, replace the oil cooler and oil cooler seals.

All these things are in the same area, and all will at some time fail. It is a tedious area to work in, so that's why I say do all at once.

Negotiate with a competent repair shop. Should be under U$2000 and you will have another 130,000 peaceful miles. Except for that POS turbo seal. That I inspect or replace every time I do the fuel filter.

I'm going to do the seal, and clean the motor as well as possible.

Then I will worry about the motor and the cooler when one or the other goes.

I have only had 2 very short limp more episodes more then two week apart and no check engine light,

I was referring to oil cooler gasket, not the actual cooler as the seal is a common problem on these engines (both 320 and 350 diesels). Why would the actuator motor needs to be replaced ? How did he determine it ?
To your question, IMHO - very fishy as I have no idea how actuator motor would cause extensive oil leak and I am not sure which actuator... Really sorry, but I am not in position to comment more on your issue without seeing the truck - lack of experience in remote diagnostics :) Good luck.


Igor.

Huh ? Did you identify these issues yourself and performed all the work by yourself ? Replacing turbo inlet seal does not require removal of the intake and oil cooler seal/oil cooler is under the intake. There is a slight difference of about 10 hours of labor...

And I totally agree with "under U$2000" comment to fix the issue. Not too sure about replacing intake manifold (are there more than one ?) and swirl motor. Never heard of oil cooler on these engines needing replacement either. You might be better off replacing the whole engine if you had to replace all those parts.

Igor.

I think the issue sis if you get oil on the swirle motor (and/or connectors) too often, you end up with problems.

Some seem to think that gunk inside the manifold the flappers stick and that caused the motor failure.

I am not so sure. There might be more than one failure mode.

However, oil inside the manifold and oil dripping outside are two very different things.

I am putting my bets on the external oil (mostly from a bad turbo seal) gunking things up from the outside.

N_Jay: The 2 limp home episodes are due to the swirl motor sticking. It sticks brief enough to trip the limp home, but not the check engine. There will also be codes stored visible through StarTec.

igor: Why I mentioned the intake, (yes there is a L and R) is that the PCV system on these cars is the weak link. It literally feeds quite a bit of oil into the engine just before the turbocharger. (That is where the oil that drips out of the turbo seal is coming from). This oil is blown through the turbo, the intercooler and to the intakes. Just before the intake it is also exposed to the EGR so the mix of the 2 causes really gummy sludge all in the intake that eventually obstructs the butterflies of the swirl motor. That will put you in limp home.

What I described earlier will be the proper fix for someone experiencing these issues. Anyone can do piecemeal repairs, but it is a bear to remove the intakes and high pressure fuel system without breaking or stripping a bolt, so while it's apart, I would suggest do all.

Dgiturbo,thanks for your inputs. I will check with my shop and see if those areas are covered. Are you aware that the actuator motor may cause the CEL on/limp mode as well?

I have experienced two causes of oil leaks on this engine, and during the process of reading up on the topic across many forums have found other causes. Here's a summary that perhaps owners & DIYers will find useful:



(1) Most common cause is faulty/failed turbocharger air intake pipe seal. This is the black plastic pipe carrying air from the air cleaner box to the intake of the turbo. There is a smaller rubber hose-pipe plugged into the side of the turbo inlet end of this pipe that carrys crankcase blow-by vapors from the nearby Crank Case Ventilation (CCV) valve attached to the passenger side valve cover. When the engine oil is filled beyond rated capacity, which is approximately more than 2/3 of the way up the area between the 2 black plastic boundary indicators on the engine oil level measuring dipstick, the CCV will pass an excessive amount of oil vapor into the turbo inlet, and when that can cause 2 nasty problems: (1) on an older faulty design air intake pipe the orange seal will leak oil slowly out and onto the top of the engine, which can cause several problems including the one described in this thread; (2) the oil vapor condenses within the engine intake system and after entering the engine intake manifold will mix with exhaust soot coming from the Exhaust Gas Recirculator (EGR) valve creating a gummy substance that eventually impedes the proper flow of air into the cylinders, cakes up the insides of the manifold, and impedes the motion of the intake actuator vanes ("stir vanes") for each cylinder.

Solution to leaking air intake pipe seal: (1) Mercedes has an improved design replacement air intake pipe seal & pipe; the old one has an ORANGE colored rubber seal, you can check by easily removing the pipe and looking at the end that was attached to the turbo intake, and some have been reported to just push onto the turbo intake without a metal pipe clamp (not all, tho); the new replacement has a BLACK colored rubber seal, and a metal pipe clamp. Fortunately, this is a fast, easy, relatively inexpensive repair that many DIYers undertake or that should not cost a lot for a mechanic to do. (2) Some owners have added an after-market (non-MB) oil-air separator device between the CCV valve and the turbo air intake pipe to reduce or eliminate the crankcase oil vapor entering the engine, available from a wide variety of manufacturers including one in Germany to address this common problem with this engine; some (such as myself) built such a separator from inexpensive parts from a hardware store. I also chose to replace the CCV valve for good measure, and MB has an updated design for that part as well.


(2) Oil cooler gasket leak; this is the second most frequently reported cause. The engine oil cooler is bolted to the top of the engine block under the intake manifold, and it in turn is connected to both engine coolant and oil passages. It cools/warms engine oil to the temperature of the coolant as they both circulate through a heat exchanger. The heat exchange device ("cooler") itself rarely goes bad, but is apparently has happened via internal corrosion, typically by the introduction of the wrong type of coolant into the engine. The majority of problems are due to one or more seal gaskets eroding over time, allowing the oil, which is under high pump pressure, to leak out onto the top of the engine block and subsequently onto other engine electrical pipes and most notably the intake stir actuator motor and eventually causing failures of those other systems. I have read reports of severe failures of one or more of these gaskets resulting in 1-2 quarts of oil added to the engine every fuel tank refill, puddles of oil on the ground, oil over both the front and rear of the engine, oil all along the underside carriage, etc, and CEL/MEL OBDC codes of low oil pressure.


Solution: Replace the seal gaskets for the oil cooler heat exchanger. This is a relatively big job, with reports of typically minimum 8-12 hrs for a mechanic or DIYer to do, as it involved removing the turbo, intake manifold, and everything else immediately above them to gain access to the oil cooler. While the intake manifold is off, it should be thoroughly cleaned of any soot & oil buildup inside (I hear that diesel or carburetor cleaning fluid works well after a good soaking, compressed air blasting, etc). As noted above, some owners have opted to replace the relatively expensive oil cooler itself while the engine is apart for future peace of mind, especially if the engine has 150,000 miles on it, and the vane actuator ("stir") motor since it's also hard to get to when the engine is assembled and is prone to failures.


(3) Leaking turbocharger mounting bracket oil seals. The high-speed operation of the turbo shaft requires oil lubrication of its bearings to maintain long life, therefore the turbo is mounted on a vertical support bracket/shaft that contains passages for engine oil to be pumped up from the engine block to the turbo bearings. That support shaft has 2 gaskets, one that is between the support shaft and the top of the engine block and another between the top of the shaft and the turbo that is bolted onto it. Either of those gaskets erode, or the bolts securing the support shaft become loose from either the engine or the turbo, and oil can leak out onto the top rear of the engine, including the hot exhaust pipes attached to the turbo causing the burnt oil smell. Replacement of these gaskets is not terribly expensive, as the turbo and its support shaft are easily removed, and the gaskets are fairly inexpensive. I personally experienced this leak with my engine and was able to replace myself.


(4) Turbocharger bearing oil seal leak/failure. This is much less common, but has happened. This will leak oil onto the top of the engine IF you also have the older turbo air intake pipe with the orange seal (see #1 above). The high speed (10,000rpm or more is not uncommon I hear) turbo shaft is hard on its bearings and associated oil seals, and with high-pressure oil pumped from the engine bearing down on the seals you can imagine that something will eventually wear out. Fortunately, Garret and other modern turbochargers are designed to last a long time, but premature failures happen sometimes. When the turbo oil seal begins leaking slowly, there will be oil on the intake vanes that looks remarkably similar to what it looks like when the intake pipe seal or CCV valve fails (see #1 above) so it may be hard to definitively diagnose one from the other (since #1 is so much cheaper to do and much more common, it's worth proceeding with doing it first anyway, including replacing the CCV valve IMO). A failed turbo oil seal can cause that nasty gummy build-up inside the intake manifold, and oil accumulation in the resonator and intercooler at the front of the engine, so should be taken care of as soon as possible. New turbos are expensive, rebuilt ones are considered by many mechanics as being as good as new at 1/2-2/3 the price, but they're still expensive and will require a few hours work to replace. It's been advised to buy a turbo along with it's exhaust vane actuator motor (bolted together) as they are better calibrated by the supplier to work together, altho there is debate among engineers & mechanics about that since the engine control module (computer) is supposedly designed to "self calibrate".


BTW, failure of the intake vane actuator "stir" motor does not cause the vehicle to go into "limp mode" as it is an idle engine speed emission control ("stirs" the air entering the cylinders for better combustion for lower exhaust pollutants) that does not lead to catastrophic engine failure potential. As a simple comparison, the failure of the turbo exhaust vane actuator motor or its linkage will lead to limp mode, as it can cause dangerous over-boost intake air pressure for the cylinders; there are other causes of limp mode, but I have not heard anyone report the stir motor failure as one.

Hi can u help whit my Mercedes benz ml320 2007
b2/6 (left hot film mass air flow sensor). value is above limit. What the problem is? Thaks

Hi ,I have same problem 2644-001 Check component b2/6 (left hot film mass air flow sensor). value is above limit.You have solved the problem?or someone knows where is the error,I changed the mass air flow and not resolved,can not delete error.Thanks

Awesome summary, Thanks!
 

Thanks for the awesome summary, I had mine up and running in no time, leaking oil from the orange seal onto the wires caused the malfunction...

--Do you happen to know the new and improved part numbers for the:

Orange seal 642-094-00-80
CCV/ hockey puck/ Bleeder Valve 642-010-18-91?

I hope a new puck CCV design may help limit the flow of oil to the turbo entry. I will take a look at some oil separator designs too, sound like a great preventative fix.

great write up eeehaw

i have had 2 of these motors- both 2008 and both of them the black plastic intake part that hold the big orange seal to the turbo cracked- more on the bottom where you could not see it

it is not a cheap part but worth the upgrade

anyone with persistent leaks with the big orange seal should pull that piece out and inspect it carefully

still change my orange seal every other oil change- i change oil on 5000 miles

Please UPDATE YOUR PROFILE in USER CP to include the year and where you live.

Post you entire vin#.

Did you ever get a solution to this post?:

"I got the following 10 codes on my car.

2527-2 check component Y27/9 (left EGR positioner)
3053-4 check component B2/7b1(intake air temperature sensor)
3052-4 check component B2/6b1 (intake air temperature sensor)
2603-4 check component B2/7 (Right hot film mass air flow sensor)
2602-4 check component B2/6 (left hot film mass air flow sensor).short circuit or open open circuit
2646-1 check component B2/6 (left hot film mass air flow sensor). Value is above limit.
2514-2 check component R39/1 (vent line heater element) short circuit to ground
2679-4 check component B76 (fuel filter water level sensor)
2526-2 test signal cable to component Y77/1 (charge pressure positioner) short circuit to ground
2530-2 check component M55 (Inlet port shutoff motor). short circuit to ground"

I have the exact same codes on my 2008 ML320 CDI. Any help would be much appreciated. Thanks!

Do you have the same blown fuses?

Mercedes dealers have “rebuilt MAF” that look like new units ) $240 with the discount and need the core returned for $35 deposit.
any way to fix a slow oil cooler seal leak without replacing the seal?

why have 2 MAF sensors when 1 will do? Twice the chance to charge?

Something like that! (Packaging)

In the quest for a universal-packaged diesel truck motor, they decided on a V6.
But they also wanted it shoehorned into any body design, including the thin hooded E-Class and R-Class.
So they came up with this intake horn/batwing that lies flat over the turbo outlet pipe and sucks from 2 airboxes squeezed in outboard of the heads.
Which then needed 2 MAF sensors (maybe).
(The Sprinter application uses one airbox, and one MAF, but it won't fit into the MB SUVs or cars)

It's a Rube Goldberg thing - why make things simple when you can make them complicated?!
Answer: Because we can!
Who cares about serviceability or cost of ownership!

The copper heating element in the PCV vent line to the air duct (batwing) can ground out on nearby metal parts when the batwing comes out for service, shorting the fuse #104 mentioned previously.
Then you have the barrage of ECU codes for sensors not working, intake flaps, boost pressure controller...

Since the amount of air restriction by a pipe is the 1/(area), it would be too hard just to increase the air tube and air filter size.
The 2012 e350 (gas 4-matic) only has one instead of 2 air filters and does fine with the same size air filter.

I received by rebuilt German made MAF with new Y-tube. It looks brand new and made stamps on the plastic has mfg date of 2/2020.
The only thing that looks different plastic weld seams are not a smooth as the original and new one has extra metal screens on the intakes.
The weakness of the turbo connection is still present. A spring hose clamp will likely lessen the change to damage the plastic due to over tightening and thermo expansion and contraction, but that would cost $0.50 more for the spring clamp and decrease the sales of replacement MAF/ Y tubes.


I find placing the air box, attaching the Y to the turbo, and finally the air boxes to the Y and bolting the air boxes is the easiest way to reassemble.

Why do German engineering make things overly complicated? Because they can or that they are well thought out to have more costly servicing?

David

I realize this is an old post. Did the MAF fix the problem?
I am getting the the 2603-4 check component B2/7 (Right hot film mass air flow sensor) error on my 2008 GL320 CDI.
Cleared the error with DAS... comes right back.
Hope you can shed some light.
Thanks
Mark

I have had the dual MAF replaced in the last year or so, it did seem to run better and the codes for MAF were fix for me.

I think with the rebuild program MB realized they needed to do something to address the frequency of failure of the part.
I mean, the failure rate is not x2, it is x-squared and then you get to pay for both to fix the issue.
I've never had much success with cleaning Bosch-type MAF elements, I think the typical MAF cleaner actually messes the sensors up.

> I find placing the air box, attaching the Y to the turbo, and finally the air boxes to the Y and bolting the air boxes is the easiest way to reassemble.
^ I just realized this over the weekend, after dinking around with putting filters on first since I've had this car. Much (surprisingly and noticeably easier!)
On the R-Class the rain tray shrouds the air filters so much that you have to loosen it and pry it up out of the way for the passenger side filter.
Over time it makes the rain tray a maintenance item, too :(, I'm expecting a new one in today.

Thanks for the reply..
It appears the filters have not been changed in a while. I bought the vehicle with about 120K.
I normally change oil and filters.... just neglected to change the air filters.
I have ordered the air filters, orange sealing boot and the MAF tube assembly.
Thanks again,
Mark

have you checked to see if fuse 104 is blown (engine bay) - I have had similar in 2 cars now and the M55 motor dies and blow this fuse which supplies to heaps of sensors - thus the multiple codes

B34chBum,
You don't seem to understand why 2 MAF sensors are used instead of one MAF.
As you stated the frequency of repair/replacement cost will be squared.
So that means more parts and service fees to collect.
It's a win-win for MBZ and the service department. $$$$

One MBZ dealer told a friend that she should have expected large repair bills for owning a MBZ.

Replacement of my MAF did not fix the problem.

>> You don't seem to understand why 2 MAF sensors are used instead of one MAF.
>> As you stated the frequency of repair/replacement cost will be squared.
>> So that means more parts and service fees to collect.
>> It's a win-win for MBZ and the service department. $$$$
Sure I do, it was driveline packaging combined with body styling - to fit the motor under the sloped low hood profile (at least, in the E and R-Class cars and perhaps the Ms not sure about GL hood clearance.
In the Sprinters the intake is single-MAF.
And I Do understand the cynical explanation (".., because we Can").
I just didn't want to beat a dead horse, which has been flogged without mercy on other forum threads here and pretty much anywhere else you go.

My car spends about 1/3 of the time with a CEL on. It came back on over the weekend. I check codes, it is O2 sensor (again). I mostly ignore, it's so frequent.
If I take a longer drive after a few drive cycles it goes out.

>> One MBZ dealer told a friend that she should have expected large repair bills for owning a MBZ.
Yes, I've been told Drive a Honda too.

>> Replacement of my MAF did not fix the problem.
Sorry to hear that. What are the codes?