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Why not just disassemble all the parts needed (oil filter housing and oil lines) and do the job right? Why cut corners?
I hear you - I have the part and I will be changing it - just not yet. I'll do it when I have another reason to tear those peripheral parts off.
The solenoid hasn't failed and there's already oil in the harness. This can, apparently, be managed by checking the connector and cleaning connections on a ~weekly basis if needed. Thankfully the connector is the most accessible one in the universe so It just takes a few seconds. Also, I would be risking additional failures/breakages/dropped-parts/bloody-knuckles/foul-language-near-the-kids by messing with the currently-functional systems I would have to take apart. It is entirely possible that there will be no reason to change that solenoid until it comes time to swap the water pump - which is likely not too far in the future. If the solenoid does start to leak into the harness, well, I'll just do the water pump early.
Last edited by QuadTurboPrius; 06-20-2023 at 08:58 AM.
Also, I would be risking additional failures/breakages/dropped-parts/bloody-knuckles/foul-language-near-the-kids by messing with the currently-functional systems I would have to take apart.
. That is the part I like about software. If the new idea fails, just recover the old file or backup. That is not possible working with real devices even though there are replacement parts, and the ultimate is working with living beings with no parts available during the work and fixing them with the "engine running" .
it requires a bit more will, but the video shows exactly the approach. With fine/thin tools and patience, it can be done, and it has been reportedly done this way by several forum members
Can you point to the reference that people post success in replacing that solenoid on their M157? Wondering if I can get more info there.
Just checked my CPS and Solenoid, 3/4 CPS and all Solenoid has oil stain.
Can you point to the reference that people post success in replacing that solenoid on their M157? Wondering if I can get more info there.
Just checked my CPS and Solenoid, 3/4 CPS and all Solenoid has oil stain.
It's posted on this site somewhere. I tried Google searching (the search feature on this site is terrible) and didn't come up with it. I think a box-end hex (not torx) wrench needs to be used. Possibly the user that reported success also ground down the tip of the replacement screw, thereby shortening it to allow re-assembly. Not sure i would do this myself. To find the post will require lots of diligent searching, unfortunately.
It's posted on this site somewhere. I tried Google searching (the search feature on this site is terrible) and didn't come up with it. I think a box-end hex (not torx) wrench needs to be used. Possibly the user that reported success also ground down the tip of the replacement screw, thereby shortening it to allow re-assembly. Not sure i would do this myself. To find the post will require lots of diligent searching, unfortunately.
Thanks! Looks like it's either pry the solenoid into the housing or sand down the oil pipe housing. I checked the screw on my M157 and believe sanding down the screw head is not necessary as long as you have open ended wrench.
I will try the installation next weekend and report back.
Alright, so long story short:
Not every M278/M157 has the "magical sweet spot" that Wanted!! mentioned. You may not have enough space between the solenoid and the oil pipe housing.
Details:
Two examples, the first one is in the video shared above, at 6:35'
You can see this M278 has enough space to easily take out the solenoid. In that case, you're lucky. I guess Wanted!! might be in this situation. So if your engine has this much of space, don't pry because you don't have to. Just patiently find the "sweet spot" and you can take out/put in without obvious obstruction. Some folks might think there shouldn't be a so-called sweet spot because the solenoid is round. Well, it's not up to the solenoid but depends on the contact point between solenoid and oil pipe housing. The housing is a rim shape so turning around the solenoid does help. It's hard to speculate until you get your hands dirty.
Second example, see the picture of my M157. It's a 2015 S63 coupe
The gap between solenoid and housing is much smaller than the one you see in the first example. My gap is like 2mm tighter which makes a significant difference.
Like Kenny mentioned in his video, it's mission impossible. Don't ever think of prying the solenoid in. I used some brutal force to pry out the solenoid at the "sweet point". In my case, this point is at 3 o clock. Taking out is possible because the solenoid has the "handle" at top which can be used as leverage.
Then it's impossible to pry in the solenoid without damaging both the solenoid and its housing.
The only solution is grinding down the oil pipe housing. Luckily we only need to shave a very tiny amount of metal, see the pic below.
I used a Dremel to grind down about 0.5mm metal at the outer edge of the rim which is absolutely fine. Then with this extra amount of space, you can easily slide the solenoid in at the "sweet point"
Two examples, two drastically different situations.
As for the screws, you only need a open end 8mm wrench and lots of patience. Not too much to talk about. Just be patient and very careful. I bought this one which did a great job.
Alright, so long story short:
Not every M278/M157 has the "magical sweet spot" that Wanted!! mentioned. You may not have enough space between the solenoid and the oil pipe housing.
Details:
Two examples, the first one is in the video shared above, at 6:35' https://www.youtube.com/watch?v=QA_nhW-4fRA You can see this M278 has enough space to easily take out the solenoid. In that case, you're lucky. I guess Wanted!! might be in this situation. So if your engine has this much of space, don't pry because you don't have to. Just patiently find the "sweet spot" and you can take out/put in without obvious obstruction. Some folks might think there shouldn't be a so-called sweet spot because the solenoid is round. Well, it's not up to the solenoid but depends on the contact point between solenoid and oil pipe housing. The housing is a rim shape so turning around the solenoid does help. It's hard to speculate until you get your hands dirty.
Second example, see the picture of my M157. It's a 2015 S63 coupe
The gap between solenoid and housing is much smaller than the one you see in the first example. My gap is like 2mm tighter which makes a significant difference.
Like Kenny mentioned in his video, it's mission impossible. Don't ever think of prying the solenoid in. I used some brutal force to pry out the solenoid at the "sweet point". In my case, this point is at 3 o clock. Taking out is possible because the solenoid has the "handle" at top which can be used as leverage.
Then it's impossible to pry in the solenoid without damaging both the solenoid and its housing.
The only solution is grinding down the oil pipe housing. Luckily we only need to shave a very tiny amount of metal, see the pic below.
I used a Dremel to grind down about 0.5mm metal at the outer edge of the rim which is absolutely fine. Then with this extra amount of space, you can easily slide the solenoid in at the "sweet point"
Two examples, two drastically different situations.
As for the screws, you only need a open end 8mm wrench and lots of patience. Not too much to talk about. Just be patient and very careful. I bought this one which did a great job. https://www.amazon.com/dp/B004RCSQNA...roduct_details
Good luck and happy wrenching.
As someone who did this at the same time as tensioners and check valves, as well as coolant lines, this is an excellent tip to just do the solenoids on the m157. This tip should be a sticky imo, along with the callout for a long box end 8mm. Theres constant confusion over the differences and ease of this job between the m278 and the m157 and this tip deserves to be easily found, given the oil harness issue. This also looks like its easily accomplished fast with a large flat file.
As someone who did this at the same time as tensioners and check valves, as well as coolant lines, this is an excellent tip to just do the solenoids on the m157. This tip should be a sticky imo, along with the callout for a long box end 8mm. Theres constant confusion over the differences and ease of this job between the m278 and the m157 and this tip deserves to be easily found, given the oil harness issue. This also looks like its easily accomplished fast with a large flat file.
Fyi if you want to get the oil out of the harness, suck it out. Optionally, no need to remove that pita actuator
I have a video showing it working but too big to post. Still, you can see the oil exiting. It would also help suck it out of the other wires.
As for the ECU, I'd open it up and see if it got in. Oil would take time to damage it so you could be catching it before that, and just might really regret it if you don't.
Well, good news folks - so far so good. My theory about cleaning out the ECU plug and any other plug that had oil residue every-so-often after changing the CPS and solenoids seems ok. I've put over 10k miles on this car since significant oil deposits were observed on the ECU pins and - well - it's still a monster. Not a single code. Not a single hiccup. I have the sacrificial pig-tails but haven't put them in yet.
So, Just keep the harness clean and replace the leaking sensors. With fingers-crossed, it will be ok. The moment it isn't I'll report back
Report back 11 months later:
2/4 solenoid and 1/4 CPS shows slight oil mark
It shows:
1. There is little benefit in changing solenoids as they will start leaking again in a year, also considering the difficulty in changing them. Better throw on the sacrificial cable and call it a day.
2. The "upgraded" CPS is still a crap. I used to believe MB put out a newer version to solve the oil seepage. Do change them periodically or buying 3rd party sacrificial cables.
Report back 11 months later:
2/4 solenoid and 1/4 CPS shows slight oil mark
It shows:
1. There is little benefit in changing solenoids as they will start leaking again in a year, also considering the difficulty in changing them. Better throw on the sacrificial cable and call it a day.
2. The "upgraded" CPS is still a crap. I used to believe MB put out a newer version to solve the oil seepage. Do change them periodically or buying 3rd party sacrificial cables.
Report back 11 months later:
2/4 solenoid and 1/4 CPS shows slight oil mark
It shows:
1. There is little benefit in changing solenoids as they will start leaking again in a year, also considering the difficulty in changing them. Better throw on the sacrificial cable and call it a day.
2. The "upgraded" CPS is still a crap. I used to believe MB put out a newer version to solve the oil seepage. Do change them periodically or buying 3rd party sacrificial cables.
Replaced my CPS's last March. 10k km's later 3/4 are leaking a very small amount. Solenoids fine. I'm tempted to try after market CPS's.
06-20-2023, 07:02 AM
. That is the part I like about software. If the new idea fails, just recover the old file or backup. That is not possible working with real devices even though there are replacement parts, and the ultimate is working with living beings with no parts available during the work and fixing them with the "engine running" . 
