I've got a M177 engine 2019 GLC63 at 35000km. Recently I went to the shop and did an oil change, the second day "engine oil level too high" and the CEL was on. So few days after I went to the shop again and let some oil out, cleared the code. Then not long after the CEL came on again, checked the code was P000028, and it said "no more information could be provided" on the scanner. The shop cleared it multiple times and it kept coming back, It had been a month and the CEL had drove me crazy!!!
We did the following checks:
1. Cylinder 7 and 8 shows balance rate of +7 while the rest were normal (all negative small number).
2. The engine is a little bit rough but not noticeable, power seemed normal. (I noticed it when I put my hand on the driving wheel and can feel it shakes, similar to the feeling when the wheel's dynamic balance is messed up, so I am guessing a little bit misfire but not much)
3. ECO Start Stop did not work for a week but after I sent the car to the shop they said now it worked fine, aux battery was checked normal as well.
4. Oil was changed again but not the filter.
5. Plugs changed, coil switched, cable checked, smoke test done. My mech guy said they are all normal.
6. Fuel injector was left alone for now as my mech said no one in the area has dissembled a M177 engine before to change fuel injector, so they don't want to do that unless we know it's absolutely the injector causing problem. Plus I am guessing if that's the case, code would show and balance rate could be much bigger.
7. Dealer had the same fault code and they don't know why, updated the powertrain software, no ECM update available.
I read through the forum and notice there's misfire and fuel injector leakage with the M177, but I doubt that's the case here since there is only one fault code P000028, otherwise there would be multiple codes showing up.
I was guessing could be either the filter or the oil pressure sensor giving wrong signal so the engine oil level is wrong all along. But my mech said the oil pressure sensor is rarely faulty and no code is shown.
So what do you guys think is triggering the CEL?

 

Leaking injector (just one) on cylinder 7 or 8. You've got to get it fixed before it floods then hydrolocks the engine.

Drive it gently to the shop it needs an injector. A compression test will also show low compression in either cylinder 7 or 8 this is because of the excess fuel leaking into the cylinder from the bad injector - it will return to normal compression once you've fixed it and drive it for a bit.

The telltale sign of a leaky injector in these cars is when ECO START STOP button doesn't illuminate or work. This is why tuners should never code this feature out as it serves as a good early warning system.

Don't fark around or delay it mate you have a bad injector. It's the achilles heel of our cars and driving it like this will grenade the engine.

 

I would think if the injector was leaking that bad it would throw cylinder specific misfire codes. That’s just a wild guess in my opinion, without any DATA driven diagnostics being performed. So if the OP puts in the injector and it’s still throwing the code now what? You just had the OP waste money. The vehicle use’s high pressure fuel pumps with fuel rail pressure sensor’s for its appropriate bank of cylinders. How about a fuel injector balance test first with the appropriate level scan tool? You should be able to find the leak down IF there is one on an HOT engine with the engine off looking at your rail pressures. DONT just load the parts cannon and throw an injector in it. That’s absurd.

 

Leaking injector will only throw a misfire code occasionally.

I've been through it myself and know exactly what this is. In the end it's up to the OP.

What's your experience on this? Bit of sh*t talking here and there yeah?

 

That means you have no idea lol

 

Just "wild guessing"

Bit of this bit of that​​​​

 

HAHAHA

 

A “Wild guess” referring to you commenting on just throwing an injector at the car. A bit trouble with the reading I see? You loading the parts cannon is a wild guess. Run some real diagnostics.

 

1. Injector balance test to rule out cylinder specific injector flow issues.
2. Hot engine fuel rail leak down analysis
3. Relative compression with a lab scope to rule out any cylinder wash

Take it to a workshop that runs real diagnostics and you should be able to pin-point the issue.

 

Again, it's not a wild guess if I've been through it.

You haven't.

So OP can do what he likes but i'm sharing real information from experience. If you know better feel free to get in touch with the the guy and diagnose his car for him.

 

Run some diagnostics on your lack of paragraphs first. Once that's solved you'll be permitted to reuse ghey words again like absurrrd 😂😂😂

 

Hahahahaha

 

I see you you’re a bit on the spectrum as well. That’s okay not everybody can read full sentence paragraphs. It’s people like you that make these forums **** because of the absolute unnecessary waste of information or time you bring to them. In what way are you helping the OP by commenting your BS? None. Didn’t think these cars were driven by immature children still 🤷🏼‍♂️

 

“I haven’t” how do you know? How do you know it’s just not a leaking Teflon seal? You don’t because you’re just guessing because you have “gone through it” what a joke!

 

Took you a whole day to come up with that response? Hahahaha fkn twit

Go on shoo.... fix your banged up sedan first and get off your high horse before sticking your beak into topics

 

👆🏼😂 My point exactly

 

Read the report. Guy wasn't even hit by drunk driver he just accidentally put it reverse then floored it in the Costco car park.

 

Now he's raging on the Private Lounge just because he couldn't secure a free 2024 AMG Calendar giveaway yesterday

 

HAHAH 😂😂😂

 

This sounds very similar to an issue I have been having lately after upgrading turbos and other components. Except I have been getting a P000000 error stating: "This error code can be ignored and erased" accompanied by a P219585 "The signal from the oxygen sensor 1 (cylinder bank 1) is shifted towards "Lean". There is a signal above the permissible limit value". My car was running fairly rough, but not alarmingly rough, at idle, with no discernable loss of power as I am about ~800whp. I pulled the intakes and heat shield off and discovered my (new) coil packs were loose, so I tightened them up, and my passenger side exhaust clamp to the turbo was very loose, so I tightened that up as well. Since doing this, the car does seem to run much smoother at idle after clearing the codes, but have only driven about 20mi since.

I just replaced the main battery and auto start/stop still does not work, despite "sail" mode working just fine and the button is illuminated green. Not that I use it, but I would like to rectify this issue as Jimmy and others said this could be fuel injector related. I will test the auxiliary battery next.

How does your oil look? Are there any signs of fuel in your oil? I'm curious if you ran or considered an oil analysis to see if that's the case. When oil was drained, did you pull more oil than the amount that the engine was filled with? If the car is reading high oil levels and there's nothing wrong with the sensor, then it's very possible that you've got a leaky injector IMO.

 

UPDATE: PROBLEM SOLVED!!!!!!

So I found another experienced workshop to check on the car, here is how they deal with the problem:

• No information on the error code: they were not able to see what exactly triggered the code (possibly someone else touched the software before) so they restore the engine unit software to stock. After few startups the CEL came on again, and this time they can see what triggered the CEL.
• Code P2A0828: Malfunction on IMAP 2. The rest of the codes are misfire-related. Mech turned off the car to check the reading under atmospheric pressure, it's still incorrect, so sensor gone bad.
• Headlights, fans, intercooler all took away, sensor changed, then no misfire, m177 smooth as silk.

TAKEAWAY: if you ever encounter unreadable code, restore the software might help as it will show exactly how the code triggered the CEL. IMAP sensor malfunction is one of the problem often encounter on M177, thanks to the AMG engineers for building such a beautifully packed engine, the sensor is cheap but the labor is INSANE! Job took two days.

Again thanks for all the discussion in the thread, hope my experience can help y'all!!

 

Thanks for the update. Glad you got it fixed. Good to hear there are some workshops running proper diagnostics still. How much did the repair run you?