kjb55

It is a 2018 GLC 300 with 15,000 miles, just purchased, and is a daily driver unlike the first owner. And the oil just changed per the updated oil spec for M274.

CaliBenzDriver

That's perfect mileage because you don't have a lot of burned oil carbon jamming piston rings.
That causes reduced compression, high blow-by pressure blowing seals, oil consumption plugging O2+Cats.

Your personal incentive is to keep it that way

When pistons are cooled normally, they don't burn oil on the spot.
Oil circulates back down into crankcase to get cooled through the heat exchanger.

Happy ownership!

JettaRed

iTrader: (1)

The TSB identifies only late model M274 engines, not the M276. It does not appear that the M276 has this "feature". Does it?

EDIT: Apparently, the M276 also has this solenoid. I wonder why the TSB did not include it.

juanmor40

Have you read the W212 thread by master @S-Prihadi ( https://mbworld.org/forums/e-class-w...ml#post8621276) where he instrumented his vehicle and monitored what this solenoid does to the engine? You will be surprised. Who in the right mind drops oil pressure above idle RPM?

CaliBenzDriver

I think the entire M27x engine class feature this dual rate pump controlled by a solenoid.

By default the normal pressure output is enabled. The solenoid needs to activated to shift the pump in Low pressure output.

That means it is fail-safe design without the need for control, the output is safe.
The troubles start when ECU software guys comand low-oil under 3500.RPM... that when things begin to smoke!

Low pressure disable piston spray squirters. These are only active above 20psi to preserve available pressure for other parts of the engine. That leads to piston overheat.... you know the rest.

Low pressure for idling... no problem.


Do you know....
-- What is the difference between a good idea and a bad one?

-- To sort out if an idea is good or bad, you simply test it to find what real test evidence show. You then analyze REALITY and decide pass/fail vs. test criteria!

In that sense keeping oil pump output set for low pressure up to 3500Rpm is not good as evidence show.

This creates a range of lubrication issues from mild to catastrophic. The only purpose this serve is to limit vehicle life by software.

juanmor40

I have not opened an M276 to see how it the oil pressure control valve is connected internally. The error most M274 are reporting is with the oil-submerged harness, not the control valve itself. However, MB is saying the control valve is irrelevant for the engine.

I have not seen the internal harness for the M276 in any diagram, see what is available in EPC. Perhaps there is no internal harness?


On the question about what engines do use this valve, you will be surprised. Nearly all the recent MB line: L4, V6, V8, etc .. See here under vehicle fitment
https://mbparts.mbusa.com/oem-parts/...lve-2781800415

kjb55

Thanks again to a lot of hard work from the contributors above. I disconnected the sensor last night, removed it from the crimp connect at the face of the engine and zip tied the wire to the wiring that it branched off of to the left. Sealed that connector and stuffed a foam insert into the sensor to protect that connector cavity from collecting dirt. I'm religious with oil changes at 5k, using Mobil1 5w-40 with the SN+/SP rating as discussed in other posts and MANN oil filter. Mileage = 15,003 miles (not KM). I'll report back.

Next - I'll look into the M276 in my 2016 E350 coming up on 35,000 miles and oil change.

juanmor40

It can be retarded, or accelerated by a service pack, sorry in MB speak is called a software upgrade during an oil service, . MB could basically control the lifetime of the engine at will. I cannot imagine what an OTA upgrade could do.

CaliBenzDriver

Yes, right! I am not entirely sure MB has vehicle owners best interest set as top priority. MB should honestly step forward and replace blown engines, like Korean 100kMi power train warranty.
Unfortunately replacing engine would not address any of the root cause... low oil while driving.

Driving cars around on marginal oil pressure serves no positive purpose for vehicle owners. I can not find any good reason to limit oil circulation while driving.


The novel way ECU manages pump solenoid remains flawed.

Bosch is trying to figure out the minimum lubrication an engine can tolerate while cruising. Bursts of Normal pressure are enabled based on a set of factors ECU controls (engine Load, Coolant Temp, xyz) -

Low lubrication control is a perilous idea to design.
Heat stressed pistons need lubrication for cooling and friction control.

The software in charge of solenoid logic is causing unnecessary impacts as highlighted eaier. Who knows exactly what conditions are coded in there. I can not guess what extra good or bad is involved - It appears fairly untested...
What happens to the oil logic when the temp sensors disfunction with open value (we've seen that in HVAC)... Default not set, lube stays disabled for lack of high temp value to enable it ? Who knows, this is not open source code. It cost millions to spin reliable code builds.

I am not going to concider updating my "production grade" ECU code without release notes of what got changed. I know super well how most "bug patches" get released: in a hury on a shoe-string .

Disabling pump solenoid entirely satisfies my testing above and beyond. Normal pressure has truly transformed my engine driveability both City/Hwy.
My engine has become a real pleasure to drive. Gas pedal is super responsive is. trims are perfect

CaliBenzDriver

Great - I am happy knowing your engine will serve you well now. Notice how the oil color is going to improve after this oil change.
For now engine internals are going to get cleaned. Burnt oil residues will get captured.
Next oil change will stay clean longer and not get burned into carbon under 500miles.

Can you help us detail how you caped the open connectors - Mine is disconnected and tied down but I know its collecting contaminants.

How to keep this clean?? (plug it back + cut one side wire )

I have not done anything there...

kjb55

Geez it's hard to get pictures. I circled in red the male plug sealed off with electrical tape. 1st over the male end, then wrapped around and zip tied, then zip tied to the wiring harness that is routed up and to the left. The sensor harness branches off of that loom. Then you can see the female clip and male end off the engine where it fastens. I did that extra step to be sure it's away from the pulley, but also much easier to tape up and fasten to the other wiring loom. The other pictures of the gray female with white center is the sensor to the left of the main crank pulley. It is stuffed with a piece of magic sponge sort of cut to size. It relatively easy to stuff it in, would also be easy to pick or vacuum out if needed.

End result, secured to wiring loom on the left with the male end taped off and tied.

the male end of the engine tab that the fastener clips on to. Further down and to the right is the sensor stuffed with foam.

Further back picture to give a view of the surrounding components.

JettaRed

iTrader: (1)

@kjb55 How does the car drive?

CaliBenzDriver

it's a turbo.... it's easy to get power from it.

How does the engine idle sound ?

Huge driveability improvements 1500Mi:
Its based on enough pressure being already available below 2500RPM to get VVT working precisely.
As VVT positioning allows it, ECU map allows more gas to be available.

This is huge because at highway speed engine is running between 1500 to 2500.RPM. Engine acts like endlessly responsive and powerful.

Gas pedal response is very firm, no need to squeeze much or kick down into RPM.

Cold starts are also smoother, use lower RPM and step down RPM faster without any nasty sounding clunkiness.

No burnt oil smell and responsive.... this is becoming a good car.


+++ DRY ENGINE WEAR...
I don't think better surface lubrication is perceivable during driving. We easily counter all frictions with more gasoline. That's what driving is all about to manage speed. Besides the whole engine is not totally dry while pump output is managed.

Not scoring cylinders, blowing up pistons or stuck rings is a long-term benefit unrelated to driveability.
👍

juanmor40

Another casualty of this solenoid, and not being aware of the TSB,

JettaRed

iTrader: (1)

I made the “mod”. My impressions here. https://mbworld.org/forums/showthrea...1&goto=newpost

CaliBenzDriver

People are well trained: they see a fault and want it fixed. The best problems to fix are those concealed without faults.

++++ Such as....:

1. the ECU voltage YoYo
2. the TCU delayed shifts (banging 3rd!)
3. the VVT struggle with oil
4. the CGW packing stored ghosts
5. the KGo overzealous delayed alarm

juanmor40

Hello @CaliBenzDriver , I am looking at ordering a new connector and used it as a cap. I think it is this part number

https://mbparts.mbusa.com/oem-parts/...sing-295451026

There is no photo , but AliExpress has this

https://www.aliexpress.com/i/2251832...apt=4itemAdapt

CaliBenzDriver

That is a great idea to preserve the engine socket with a decoy male/female extension.

You know I am not too WIS/EPC savy to XRef P/N.

As of today .... I would not advise plugging solenoid back for fear of it jamming with shavings that may have accumulated in the oil conduite... that woud be bad karma...

I unplugged and won't back track even for a deep dive in a sub. with MS!


You know how the TSB says this is a good fault: that much is true - Let it rot unplugged. I too live a short distance from salty ocean.

Say you try it for a weekend and your have mixed results, then stick it back together, no rust!

Let me write you a safe higher mileage test procedure - PM.

JettaRed

iTrader: (1)

Ordered some. (Hope they fit.) Thanks

S18NGL

I've just spent the last couple of hours reading this and other similar threads, much to the annoyance of my wife who wants me to get on with tidying up my office. The reason for looking through these threads is that I've just had my 2018 GLC300 4Matic serviced at my M-B dealer. The amber engine light was on, so I had them do an (amazingly expensive) diagnostic test. The test came up with the P06DA00 code, and an estimate of over $2,000 (Cdn) for repair. The car was running okay, and I told them to leave that repair for the time being until I could either afford to have them do it, or find another aftermarket shop whose labour rate was a lot less.

My question is as follows: To judge from many of the contributions to this and other threads, it appears that the solenoid setup seems to have a retarding effect on engine power and driveability. Many contributors talk about much improved power after taping up the solenoid leads and just leaving it alone. Is this a recommended solution - should I just keep the $2,000 and enjoy a better drive, or are there side issues which may affect longevity? My car has about 80K km (50K miles) on it, and we intend to keep it for a few years.

Thanks for any replies.

JettaRed

iTrader: (1)

If you have read through everything here, there, and on the W212 AMG forum, you have your answer. Is the amber engine light still on? If so, it is not due to P06DA00. Do you have your own Mercedes scan tool? You probably could have purchased a good Mercedes-specific tool for less than you paid the dealership.

S18NGL

Thanks, JettaRed. You have put your finger on one of the issues that was causing me problems; the dealer's test diagnosed the problem as P06DA00, without any other issues showing up, but many of the posts on this thread say that that fault alone would not cause the amber warning light to come on. I don't have a Mercedes scan tool. What is it called, and where could I get one ?

Thanks

arifk

You can get iCarsoft MB tool. That works well. There’s also Xentry SDS clones on eBay. I’ve had good experiences with both.

arifk

Wondering if the location shown is the same for the M276 turbo engine in the 2015 GL450? I have the same error code plus the right intake VVT gear rattle.

juanmor40

Please be careful, perhaps double careful, because you have 4 cylinder engine that is known to throw pistons. Check lawsuit in progress in California.

Here is the summary from MB


It is very clear, to me , that the fault can be ignored UNLESS otherwise specified in the guided test.

Some members here never had the code, and went ahead and remove the connector. That should be no problem. HOWEVER, yours has a CEL and it has not been diagnosed to be something ELSE yet; therefore, the existing code cannot be dismissed w/o further confirmation. Fingers crossed is something else, but with 4 cylinder spotted history I would find a good MB independent mechanic and diagnose further. In particular cyl no 1, and boroscope if possible