kevm14

It's the tune. This behavior hasn't happened with any stock vehicles.

WRC-LVR

Well.. it is entirely possible the ecu has coding in it and it does inject results from it under certain circumstances. No way to know until some expert coder finds it and deciphers the code and where/ what conditions come into play. Then figures out what the code directs the engine ECU to do. Hard to believe it would then make the engine stall but you never know. It could be leaning out the AFR or what ever.

In my mind, it could also be the HPFP driven off the camshaft that does rely on the oil flow and pressure from the pump. Could it be that sitting on an hill incline with higher oil pressure and a slightly wonky HPFP due to the camshaft lobes already worn and moving forward or reverse or which ever direction, then trigger a momentary fuel pump loss of pressure ( high load low rpm ) and a sudden stall? It could also be entirely unrelated.. perhaps the low pressure fuel lift pump at the rear of the car ?

OP If it was me i would log several parameters nder those conditions including fuel pressure, timimg, AFR, throttle position, knock and of course oil pressure. Since it is repeatable you should be able to get a snapshot of what is going on at the time
You can use a quality OBD2 logger and Torque Pro or several other software to capture the data

In the meantime, for many people, the upside is better oil pressure, and many report overall seemingly better running of the car. Plus it stands to reason that having fulltime oil pressure MUST be better for the health of the engine.

kevm14

The most logical explanation for me is that the combination of tune and mods created and then band-aided a drivability issue/scenario. When proper operation of all components sensitive to oil pressure is restored, the band-aid actually becomes a liability. Or, there is a mechanical issue that lower oil pressure is somehow masking but I have no clue what that could be.

A dumb but simple tuning example is if you had a car that couldn't quite maintain proper fuel flow at high demand, resulting in fuel pressure drop at the HP peak. Call it 5-8 psi on the low pressure side. Well, a dyno tune would have worked around this by fiddling with the map, artificially increasing injector pulse width to get to the required flow at this (improperly) decreased fuel pressure (because the pump cannot make the flow @ proper pressure, but CAN just barely make it at lower pressure, a common characteristic of pumps at their flow limit). So all is well and good until you upgrade the fuel system to do what it is supposed to and bam, now you are too rich at the top end. In this scenario, the upgraded fuel pump didn't "cause" the rich issue/bog, but rather exposed the previous band-aid fix (and now the tune can be updated to work the way it should have). This is my logic for my initial comment.

kenneyd

You're car is literally stalling? Like it shuts off while driving? That's not good, but to be honest, I don't see how that is cause by a few extra PSI of oil pressure
if it were my car, plug the solenoid back in...both the verify that your car is working normal, and to figure out what is wrong as I think something else is causing this.

My car has had zero drawbacks, and I've set my best draggy times with it unplugged

OldManAndHisCar

I am not at all a fan of ECU tune on Dyno, not for a Daily Driven or street car.. This is from cars years back that seem to be no less 'intelligent' than current automotive ECU. We would tune my cars (Dyno) and then days later get wonky results due to everything from humidity, ambient air temps to fresh gas in the tank (I remember going nuts when they went from three pump hoses to one - that meant that there might be some "cheap gas" in the hose polluting my premium fuel...

kevm14 makes a very valid point that in general most ECU tunes are nothing more than a Band-Aid to correct an issue we as tuners created over the stock settings of a car. I am however not certain that altering an oil solenoid will then tell the ECU anything about the fuel due to the silent code. My thinking would be that the solenoid is driven by an RPM based parameter, not invoke a fuel flow result on if it is on or off. From there, if it did, it would be a non-issue for those who have opted to put a dummy solenoid into their car to rid the ECU of the code (mine are on their way on the slow rikshaw from China). In my past (Mitsubishi Turbos and Porsche Turbos) - tuners ideas were more than snake oil on the corner of a carnival market. They all made wild claims, oddly, back them most of them wanted us to go to alcohol injection....just like medical snake oil sales men.

juanmor40

If I recall correctly, the solenoid uses a two-wire connection to activate/disable. There is no feedback mechanism about the level of pressure. The ECU can tell if the solenoid is there because the circuit is complete, then it can activate, or not the solenoid.

It is possible the ECU could have a failsafe mechanism (like it does for the limp mode) when the solenoid is "not available for whatever reason". So far, we know it is the P06DA code. For those with oil pressure sensor, we have also seen/read about a true CEL in the cluster but not engine behavior changes yet.

If the vehicle in question is misbehaving, there are two alternatives to test:
1 - Reconnect the solenoid, keep the tune, and test
2 - Remove the tune, keep the mod, and test

If both tests pass, the likely conclusion is that the tune, for some reason, relies on the low oil pressure.

WANTED!!

OK. "Sure", it's the tune. But is it really?? No.

The new variable added to my combination is the unplugging of my sensor. The tune was there long prior to my unplugging the sensor, and this cold temp behavior doesn't occur when the sensor is plugged in.

Again, I'm a strong believer in this sensor being a stupid idea. Anything that restricts oil flow and not be considered a critical system to the ecu bogles my mind. I'm not plugging it back in.

If this truly is the tune, this is a new area of scaling for temps that tuners wouldn't normally look at. Had I not been forced to drive my car in the colder temps because my daily was down, I would never have noticed or experimented. I'm hard pressed to believe that this would be unique to my tune, let alone a stock ecu. I'm betting it affects all of us, and we just don't give it much thought because it's fairly mild, or most people don't drive these cars year round.

Plus, with it being an issue that goes away once the engine warms up after a fairly short interval of driving time, again this is a behavior that most people will most likely waive off.

What I haven't tried is running a ghost sensor to see if that affects behavior. I'm running out of cold temp days and will be unable to do anything more with the car beyond driving it as I'm leaving the country for a while due to work. Someone else would have to try it and report on that one.

OldManAndHisCar

Also - I have now heard from two separate Mercedes shops, one the dealership, one a local Benz shop - if that solenoid has an issue, the standard "fix" is to not fix it if the solenoid is in the open position. That being the case (please confirm if this is wrong)...would Mercedes not have already run through the scenario with their engineers? To that, our GLS is going in for new motor mounts this week...the Mercedes Dealership (Mercedes of South Orlando) has agreed to disconnect the oil solenoid on that car while they have it in the air for the mounts....why would a dealer agree to that if it was a potentially negative thing?

kevm14

Same system on M276, M278 and a few other applications, most of which ARE driven year round. I guess it is worth parsing through your symptom conditions again to see if other folks can notice the issue, if they look for it.

WANTED!!

Clearly you didn't actually read my post. I did test 1. Plus the tune is not the new variable.

Test 2 for me is not pheasible. I run a Kleeman K1 tune, which is bench flashed. I would need a second ecu. I'll leave that for someone else due to cost and non-availability to continue experimentation as posted above. Sorry.

kevm14

Yes, the same way that swapping fuel pumps in my example scenario could lead you to believe that the new pump is a "problem" because it made the car run worse.

Can you concisely outline the exact conditions that will recreate the problem every time?

juanmor40

Unfortunately, that is not true. You already have one variable = TUNE, and with the mod you have two: TUNE + MOD

Your test is inconclusive to the whole community, but very conclusive to your vehicle.

To isolate the defect several tests (as I mentioned previously) have to be done. As @kevm14 mentioned, your car evaluation may be polluted by previous "band-aid"

WANTED!!

There are more than a few "standard fixes" by multiple makes that are stupid. Just because it's a known point of failure doesn't mean Mercedes has to do something about it. If the engine could destroy itself and not kill or injure the driver/occupants, and the car could still run mostly correctly without it plugged in and not run afoul of the epa or nhtsa, then it's a case of the positives outweighing the negatives. If the probability of that failure happening outside warranty is more prevalent, then even less motivation to care. Most people would balk at replacing the sensor given the labor involved in doing it.

By and large, our cars drive fine without it plugged in. Even in my case, my car is not by any means undrivable. The range in which this is occurring is not the norm, and again clears up pretty quickly. Full disclosure, it took me 2 solid months of playing to figure this out and I only did it because it annoyed me. Plugging the sensor back in was kinda a "hail mary" test. 3 weeks of my testing was spent trying see see if things like Garage parking vs outside parking had an affect. It did as my garage is heated.

My long winded response and point to it is most people wouldn't notice a difference, and the car drives otherwise 98% fine.

WANTED!!

Time out. Are you actually saying my own findings, which are in a small part in contrast to the overwhelming "perfection" that this mod has claimed to be, have no value because I cannot recreate everyone else's level of modifications?

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.

AMGandS1K

So what were the test parameters of your extensive testing?

How much fuel was in your tank when you performed these tests? Was it always the same fuel from the same station?

Are you parked on a hill on start-up?

When EXACTLY does it stall? You've only mentioned it stalls if you don't drive HARD within 5 minutes of start-up. I've never met anyone who would prescribe to drive these cars hard within the first five minutes, ESPECIALLY in the 40F ambient temps.

Are you letting your car warm up? What oil and coolant temps are you letting them warm up to before driving?

What oil and coolant temps are you seeing when the car stalls?

Have you actually performed an oil pressure test to confirm your pump is working with reading within spec and also matching an approximate similarity with the others who have tested and posted such tests?

What oil are you using? How long ago was it changes? Have you checked your oil level?

Has your transmission been serviced within the past 40K miles?

What codes pop up when the stall occurs?

Why did none of your testing include an OBDII reader and some cheap logging software?

Other than simply stalling, can you describe what else you observe during the occurrence? What kind of noises come from the engine bay? Are there any weird stuttering or jolting? Any weird smells?

AMGandS1K

Overall a stalling issue leads me immediately to the simplest solutions to investigate first: air, fuel, spark.

I forgot to ask about the last time you changed your spark plugs and your coil packs.. Extremely common failure point, especially on tuned E63s.

WANTED!!

I don't know how I missed your post earlier.

Yup, I can make it stall on a steep enough grade if I leave the car parked outside overnight and the morning temps are cold enough even with about 3 minutes of warm-up/idle.
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.

AMGandS1K

If you don't mind humoring me and answering the previous questions I posted, that'd be a big step forward to investigating this issue. You really should recreate this with an OBDII logger. If the engine is stalling there is bound to be a code of some kind.

OldManAndHisCar

I will say, I did notice a "rough idle" - no codes since my last oil change (LiquidMoly) 10-40. Even by the time I want to check it out it self resolves. Over night I am going to plug my solenoid back in and see if the car does the same tomorrow.

AMGandS1K

So, would it be more succinct to say a rough start-up? or are you sitting in traffic and notice this rough idle? Can you describe it? I had some weird idle vibrations that used to occur when I'd be sitting at a traffic light for a few minutes. But it would go away after ~30 seconds. (Pre AND post-solenoid unplug)

OldManAndHisCar

Just rough idle and bouncing RPM from 1200 <-> 1500 or so, in the 40 seconds or so between starting the car and backing out of the garage. Only first thing in the AM, our garage temps are never lower than 60F over night. I will jack up the car and plug in the solenoid overnight and video the start up, unplug it (next day) and do the same.

Could be related...who knows.

AMGandS1K

That's an awfully high idle. Are you talking about a cold start before the RPMs drop?

TomZVB

Not much to add here but just want to mention that I drive the heck out of my SL63 (perf package, no tune), the solenoid has been unplugged for about 1500 miles, and never once have I had a stalling issue. I do wait for the oil temp to reach proper operating temp before giving it hell, but I’ve been out in sub-30 degree weather and have run it to redline without a single complaint. I pulled the plug (out of the front cover, lol) almost three months ago. We don’t have many hills here at the coast so can’t really test the incline thing.

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?

OldManAndHisCar

Yes, in the seconds right as I start the car, after 45 secs or so it drops and there is the audible change. Same behavior in our GLS, only the GLS is never not smooth.

kevm14

My first thought is it's part of the catalyst warmup routine which really jacks around with spark advance and cam timing.