Oil pump solenoids




Interestingly, it doesn't occur if I have the sensor plugged in and drive it under the same conditions, if the sensor is unplugged but the car is parked in my garage overnight, or if I drive the car around the neighborhood for a bit before hitting that same hill.
Only when the car is too cold/outside overnight, temps are low enough at time of driving, the sensor is unplugged does do this only once. Also interestingly, it doesn't re-occur unless the car sits overnight. I have to deliberately recreate those conditions to do it. If the sensor is plugged in, I can't recreate this.
If this changes before I leave the country, I'll report back.
Solenoid unplugged
Cold soak overnight (not in the garage). What outside temp?
Your car is cold started and driven ~3 minutes
You stop on a hill, in drive, but not moving? Or you are moving?
The engine will........stall? Run rough and then stall? What exactly happens? Coolant temp? Oil temp? Fuel trims, the whole 9.
We need this info.
Last edited by kevm14; Feb 28, 2024 at 11:54 AM.
Regarding the stalling issue, it would be good to know what oil pressure is like at startup (and on an incline). Maybe you have a stuck solenoid and the engine is failsafe-ing itself?




I don't have a logger, otherwise that would be a non-issue. I do have an sds. When time permits, I'd be happy to scan for codes. However, it hasn't thrown a check engine light when it does it.
Frankly, I did not go looking for or expecting to find this. This was an absolutely unexpected finding on my part. I simply plugged the sensor back in to rule it out as my problem fully expecting there to be more, and not expecting the sensor to fix my problem. Me repeating the experiment over days on end was me saying "this has to be a fluke". I'm more shocked than anything that it wasn't.
I'm otherwise happy with this mod. Overall, the car feels better.
Been hesitating to report this, but I do have a negative behavior associated with the sensor unplugged vs being plugged in. In colder weather (40(s)f and below), when I first drive the car if I don't drive it hard enough for about 5 minutes it'll stall /bog out under high load/low throttle. I've stalled it multiple times on a hill in my neighborhood on the way to work in the morning .
Did the transmission adaption reset, and no change. Replaced my throttle pedal, no change. Out of morbid curiosity, plugged in the sensor and it went away. Unplugged it overnight, it came back.
I'm torn as I feel the pros of having the sensor unplugged outweigh the cons. However, this behavior goes back to what I initially said near the beginning of the thread that I'm hard pressed to believe the sensor doesn't have some other affect associated with it other than just oiling. Clearly it does. Or I shouldn't be able to do this.
What this tells me is the ecu is telling the sensor to reduce/increase oil flow to some extent based on load and temps. While the primary purpose may be emissions and fuel efficiency, that clearly has an effect on low rpm drivability that may need some adjustment in the ecu to compensate for this change.
As has been noted several times, the solenoid only RESTRICTS normal oil pressure and the failsafe default condition is disabled, meaning normal pressure base on engine speed up to ~60 psi (4 bar). Also, we see TIPS documents that say to ignore the fault.




Last time I checked, NO ONE in the thread has been held to that standard let alone have the abilities to recreate every weather, temperature, and load condition. Heck, no one has yet to put the car on a steady state dyno and do a full before and after comparison of normal driving under varying temperatures , load and throttle.
If you REALLY want to go there, then let's go there and say nothing presented in this entire thread is conclusive to the community because none of that has happened.
Otherwise, let's take my findings for what they are, a point of data for the pool as an area for folks to either explore more in-depth or just add to the overall input so far.
Sorry I found a side effect I wasn't looking for or expected. Sorry I put in my time to experiment further. Sorry I could recreate my findings under limited conditions. Sorry the mod everyone loves probably isn't perfect.
What I meant is that more tests are required since there are now 2 variables involved in your case. If we do not complete "all the tests", it is difficult to conclude, only a possible cause. That is all. I also understand that the tune being flashed, and non-removable, the other tests are not possible preventing us from concluding something. It becomes antoher data point for the analysis
A similar argument we had with the true CEL, and no CEL differences. After understanding that some cars have the oil pressure sensor, we sorted out that issue.
I don't have a logger, otherwise that would be a non-issue. I do have an sds. When time permits, I'd be happy to scan for codes. However, it hasn't thrown a check engine light when it does it.
Frankly, I did not go looking for or expecting to find this. This was an absolutely unexpected finding on my part. I simply plugged the sensor back in to rule it out as my problem fully expecting there to be more, and not expecting the sensor to fix my problem. Me repeating the experiment over days on end was me saying "this has to be a fluke". I'm more shocked than anything that it wasn't.
I'm otherwise happy with this mod. Overall, the car feels better.
If you're going to blow that off, which it sounds like you will, I'd at least buy a dummy solenoid and try to replicate it.
At the minimum check your oil level.
I do believe that while unplugging the solenoid is a cause of this behavior, it may not be the root or only cause, but has somehow amplified a hidden problem or problems that need to be investigated. Just because a problem does not trigger a CEL does not mean there is not a code waiting to be uncovered. The P06DA00 is a perfect example. CELs are only triggered if the fault has a direct affect on emissions--they do NOT alert on every problem. That's why waiting for a CEL is not a good idea. Get a proper Mercedes scanner and know for sure.
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I do believe that while unplugging the solenoid is a cause of this behavior, it may not be the root or only cause, but has somehow amplified hidden problem that needs to be investigated. Just because a problem does not trigger a CEL does not mean there is not a code waiting to be uncovered. The P06DA00 is a perfect example. CELs are only triggered if the fault has a direct affect on emissions--they do NOT alert on every problem. That's why waiting for a CEL is not a good idea. Get a proper Mercedes scanner and know for sure.




I do believe that while unplugging the solenoid is a cause of this behavior, it may not be the root or only cause, but has somehow amplified a hidden problem or problems that need to be investigated. Just because a problem does not trigger a CEL does not mean there is not a code waiting to be uncovered. The P06DA00 is a perfect example. CELs are only triggered if the fault has a direct affect on emissions--they do NOT alert on every problem. That's why waiting for a CEL is not a good idea. Get a proper Mercedes scanner and know for sure.
Last edited by WANTED!!; Feb 28, 2024 at 12:34 PM.
What I meant is that more tests are required since there are now 2 variables involved in your case. If we do not complete "all the tests", it is difficult to conclude, only a possible cause. That is all. I also understand that the tune being flashed, and non-removable, the other tests are not possible preventing us from concluding something. It becomes antoher data point for the analysis
A similar argument we had with the true CEL, and no CEL differences. After understanding that some cars have the oil pressure sensor, we sorted out that issue.




Maybe a bad spark plug at startup? Fouled?








my Car w176 AMG A45 MJ2017 facelift stock
i got this code P06DA00 by 53k miles and drove without any problems 10k miles now. If i dont have any scanner "Prodiag"
I would never have known. My oldschool mechanic told me to repair this for 600€
Can i ignore this code for my car too ?
Last edited by Lotty; Feb 28, 2024 at 05:13 PM.




my Car w176 AMG A45 MJ2017 facelift stock
i got this code P06DA00 by 53k miles and drove without any problems 10k miles now. If i dont have any scanner "Prodiag"
I would never have known. My oldschool mechanic told me to repair this for 600€
Can i ignore this code for my car too ?
Many cars with this code have a harness defect that perfectly disables the low oil pressure, the way we like.
Even for free I would not get my oil pump fixed to enable low pressure!!
Many cars with this code have a harness defect that perfectly disables the low oil pressure, the way we like.
Even for free I would not get my oil pump fixed to enable low pressure!!

I don't have a logger, otherwise that would be a non-issue. I do have an sds. When time permits, I'd be happy to scan for codes. However, it hasn't thrown a check engine light when it does it.
Frankly, I did not go looking for or expecting to find this. This was an absolutely unexpected finding on my part. I simply plugged the sensor back in to rule it out as my problem fully expecting there to be more, and not expecting the sensor to fix my problem. Me repeating the experiment over days on end was me saying "this has to be a fluke". I'm more shocked than anything that it wasn't.
I'm otherwise happy with this mod. Overall, the car feels better.
FWIW I live in a cold climate, have had the solenoid unplugged for months, and have not experienced any stalling or drivability issues. Car is stock.
We just don't know for those cars with the oil pressure sensors how the feedback to the ECU works.




It's safer to unplug this time bomb clean off. Find the time to pull the plug and take couple pictures you'll post in favorite MBWorld chassis board.
Your engine is now ABNORMALLY MORE RELIABLE because you are lucky.
BTW now we can thank you as you have tested this mod longer than all of us combined.
I change every 6 months or max 120h my oil. On next service i will unplug this s***
Or i will show tomorrow maybe i can unplug this cable on top. But im sure i need a lifting platform and unplug it from the bottom. IDK.
Last edited by Lotty; Feb 28, 2024 at 07:40 PM.




