SMG II - MLR Engineering Accumulator

[bmrdvr]

Sorry for the delay. Yes ventilation=bleeding in this context; sorry to confuse.

I have over 3000 miles on the accumulator and zero issues. Very happy with it over-all!

[zivagolee]

+1, just installed the MLR rebuilt pump with upgraded reservoir and accumulator. It is pretty huge so had to modify the custom bracket a bit.
Just went to Laguna without issues -- doing 3 more track days in the upcoming month so let's see if continues to hold up.

[JokerElite]

Love to hear these SMG success stories!

[0-60motorsports]

+1, just installed the MLR rebuilt pump with upgraded reservoir and accumulator. It is pretty huge so had to modify the custom bracket a bit.
Just went to Laguna without issues -- doing 3 more track days in the upcoming month so let's see if continues to hold up.

Excellent!

[bmrdvr]

Love to hear these SMG success stories!

I'm all in on SMG. I also have an E60 M5 that I'm playing with. SMG is cool but not for the feeble minded; it takes effort to understand it technically and time to learn how to operate it effectively. SMG cars have loads of character but to each their own.

[bmrdvr]

I should say that I rebuilt my SMG pump with MLR seals (including actuators) and haven't had any issues. I did have issues with their actuator seal kit though specifically with the seal for the actuator rod. I would really like to just source those parts though as they charge an obscene amount for them. I also run a Burkhart motor as well. I've seen a few posts about the MLR motor failing so I would likely buy another Burkhart again. I think my largest concern on-going for SMG II is what to do about gear position sensor (GPS) on the back of the actuator... eventually they'll wear out. The BMW ones are crazy money and I'm sure they're not going to be in production forever (if they're even still in production).

[Vonbimmer]

Another vote for MLR here (knocks on wood), I bought the seal kit for the pump in my wife’s SMG vert and while taking it apart broke a couple connectors de-pinning for the new motor and MLR was great to work with returning the parts and going with a full rebuilt unit

[bmrdvr]

Alight well the fun came to an end. Did another long roadtrip (~4500 miles) and started having issues with heat. I've had this car since 2011 (had 62K on it when I got it) and have put just under 100K on it and never once have I ever had an SMG-related problem. It's never leaked, never thrown a light, used up a pump or motor etc. I've done a ton of preventative maintenance on it though including all the solenoid seals, a Burkhart pump motor, slave cylinder, clutch, actuator seals, etc. The last piece I wanted to make bulletproof was the accumulator as the testing was showing my factory one was on the low end of passing the test.

I think the highest ambient temp I saw was upper 80's but after sitting in some traffic I got the yellow cog. Looked at things with ISTA+ and it was complaining about the pump running too much (SMG: On period, hydraulic unit (OBDII: P1717)). This happed a couple of times on my trip causing the car to drop out of gear into neutral which was EXTREMELY unnevering for me as it's literally never happened to me since I've owned it. The only thing that's changed is this accumulator. Now, I know they offer different fluid which I believe is a heavier viscosity but I'm surprised I was having these issues.

My plan is to take the unit off the car and I would like to send it back to them to test. If it comes back good to their spec, then I'll just keep it as a spare and buy an OE one while I can. I like the concept but to me this is absolutely an aftermarket solution and not a drop in replacement since it's 1) way longer and fatter and 2) seems to not like the CHF11S. As well know, these things don't like heat and for track use, I think relocating as pictured above makes a ton of sense but for street car that sees only long road trips - I need something that is truly as good as the factory.

Perhaps I'm being a bit harsh so I'll update with whatever comes of this. The car is done for the season so I won't be doing any testing for another 6-8 months. I think I have about 10K miles on it though and of all the things that could have an issue with a high-milage E46 M3, this was not what I was expecting...

Also as an FYI: my ISTA+ accumulator tests the following morning when everything was cooled off showed 36.4bar (spec is 29-41bar) so it was fine until it got heat soaked. Also of note was after the car fell out of gear, as long asI could get it up to highway speeds, it would settle down and not have any issues. It was only in stop-go traffic when it had issues.

EDIT2: I should state I have CSL code in the SMG module as well... not sure if that would make a difference but that was something that had changed since the last trip (first trip for 3000 miles or whatever was didn't have the CSL software).

[bmrdvr]

+1, just installed the MLR rebuilt pump with upgraded reservoir and accumulator. It is pretty huge so had to modify the custom bracket a bit.
Just went to Laguna without issues -- doing 3 more track days in the upcoming month so let's see if continues to hold up.

Are you running their fluid and do you have their finned aluminum reservoir? I know Burkhart have a fluid they supply as well which I did run at one point when I did the motor but I ended up switching back to CHF11S because I couldn't be arsed to get their special fluid...

[zivagolee]

Are you running their fluid and do you have their finned aluminum reservoir? I know Burkhart have a fluid they supply as well which I did run at one point when I did the motor but I ended up switching back to CHF11S because I couldn't be arsed to get their special fluid...

I'm using standard CHF-11S now that it's relocated. I don't see an issue with heat as I did with the stock location.

[oceansize]

Alight well the fun came to an end. Did another long roadtrip (~4500 miles) and started having issues with heat. I've had this car since 2011 (had 62K on it when I got it) and have put just under 100K on it and never once have I ever had an SMG-related problem. It's never leaked, never thrown a light, used up a pump or motor etc. I've done a ton of preventative maintenance on it though including all the solenoid seals, a Burkhart pump motor, slave cylinder, clutch, actuator seals, etc. The last piece I wanted to make bulletproof was the accumulator as the testing was showing my factory one was on the low end of passing the test.

I think the highest ambient temp I saw was upper 80's but after sitting in some traffic I got the yellow cog. Looked at things with ISTA+ and it was complaining about the pump running too much (SMG: On period, hydraulic unit (OBDII: P1717)). This happed a couple of times on my trip causing the car to drop out of gear into neutral which was EXTREMELY unnevering for me as it's literally never happened to me since I've owned it. The only thing that's changed is this accumulator. Now, I know they offer different fluid which I believe is a heavier viscosity but I'm surprised I was having these issues.

My plan is to take the unit off the car and I would like to send it back to them to test. If it comes back good to their spec, then I'll just keep it as a spare and buy an OE one while I can. I like the concept but to me this is absolutely an aftermarket solution and not a drop in replacement since it's 1) way longer and fatter and 2) seems to not like the CHF11S. As well know, these things don't like heat and for track use, I think relocating as pictured above makes a ton of sense but for street car that sees only long road trips - I need something that is truly as good as the factory.

Perhaps I'm being a bit harsh so I'll update with whatever comes of this. The car is done for the season so I won't be doing any testing for another 6-8 months. I think I have about 10K miles on it though and of all the things that could have an issue with a high-milage E46 M3, this was not what I was expecting...

Also as an FYI: my ISTA+ accumulator tests the following morning when everything was cooled off showed 36.4bar (spec is 29-41bar) so it was fine until it got heat soaked. Also of note was after the car fell out of gear, as long asI could get it up to highway speeds, it would settle down and not have any issues. It was only in stop-go traffic when it had issues.

EDIT2: I should state I have CSL code in the SMG module as well... not sure if that would make a difference but that was something that had changed since the last trip (first trip for 3000 miles or whatever was didn't have the CSL software).

O-rings and the internal seals don't last forever particularly within the environment of a car engine, this was bound to happen and will likely continue when in traffic for extended time. If you're having heat issues you have three options: rebuild, buy new, buy MLR rebuilt. You can relocate, but that won't fix overheating issues if your internal seals are tired.

[WOLFN8TR]

I think the highest ambient temp I saw was upper 80's but after sitting in some traffic I got the yellow cog. Looked at things with ISTA+ and it was complaining about the pump running too much (SMG: On period, hydraulic unit (OBDII: P1717)). This happed a couple of times on my trip causing the car to drop out of gear into neutral which was EXTREMELY unnevering for me as it's literally never happened to me since I've owned it. The only thing that's changed is this accumulator. Now, I know they offer different fluid which I believe is a heavier viscosity but I'm surprised I was having these issues.

EDIT2: I should state I have CSL code in the SMG module as well... not sure if that would make a difference but that was something that had changed since the last trip (first trip for 3000 miles or whatever was didn't have the CSL software).

I have a 2005 SMG M3 with all original SMG equipment running the CSL SMG Tune. I daily drove my car for years in the Hot Las Vegas summers, temps anywhere from 100-120 degrees and NO issues. So I don't think that's the issue at all. I do have a vented hood, ceramic coated headers and a Spal electric fan to aid in keeping the engine bay temps down. Either this really helps or I'm just very lucky, who knows. Good luck with your SMG issue.

[Irhase46m3]

Alight well the fun came to an end. Did another long roadtrip (~4500 miles) and started having issues with heat. I've had this car since 2011 (had 62K on it when I got it) and have put just under 100K on it and never once have I ever had an SMG-related problem. It's never leaked, never thrown a light, used up a pump or motor etc. I've done a ton of preventative maintenance on it though including all the solenoid seals, a Burkhart pump motor, slave cylinder, clutch, actuator seals, etc. The last piece I wanted to make bulletproof was the accumulator as the testing was showing my factory one was on the low end of passing the test.

I think the highest ambient temp I saw was upper 80's but after sitting in some traffic I got the yellow cog. Looked at things with ISTA+ and it was complaining about the pump running too much (SMG: On period, hydraulic unit (OBDII: P1717)). This happed a couple of times on my trip causing the car to drop out of gear into neutral which was EXTREMELY unnevering for me as it's literally never happened to me since I've owned it. The only thing that's changed is this accumulator. Now, I know they offer different fluid which I believe is a heavier viscosity but I'm surprised I was having these issues.

My plan is to take the unit off the car and I would like to send it back to them to test. If it comes back good to their spec, then I'll just keep it as a spare and buy an OE one while I can. I like the concept but to me this is absolutely an aftermarket solution and not a drop in replacement since it's 1) way longer and fatter and 2) seems to not like the CHF11S. As well know, these things don't like heat and for track use, I think relocating as pictured above makes a ton of sense but for street car that sees only long road trips - I need something that is truly as good as the factory.

Perhaps I'm being a bit harsh so I'll update with whatever comes of this. The car is done for the season so I won't be doing any testing for another 6-8 months. I think I have about 10K miles on it though and of all the things that could have an issue with a high-milage E46 M3, this was not what I was expecting...

Also as an FYI: my ISTA+ accumulator tests the following morning when everything was cooled off showed 36.4bar (spec is 29-41bar) so it was fine until it got heat soaked. Also of note was after the car fell out of gear, as long asI could get it up to highway speeds, it would settle down and not have any issues. It was only in stop-go traffic when it had issues.

EDIT2: I should state I have CSL code in the SMG module as well... not sure if that would make a difference but that was something that had changed since the last trip (first trip for 3000 miles or whatever was didn't have the CSL software).

Hi There - I'm currently on this same boat but i have not had enough time to troubleshoot to the extent that i wanted to, couple of things in my current environment, i have two fully functional pumps, both of which have been replaced (internal oil pump seals, solenoid seals, etc) - One pump has a new accumulator bought from BMW, the other pump has the original accumulator that came used from when i bought the pump - the pump currently in the car is the one with the old accumulator, this one is giving me the COG while hot - I then swapped the accumulator for the new one, this helped tremendously but the issue returned (it did however, make it more difficult to overheat) - My assumption here is that i did not bleed enough the system when i swapped the acc and air might causing this COG

Note: The original pump of the car never gave me any issues, even after replacing seals, etc. Even replaced the accumulator with a bmw one as preventative, no issues in any temp spectrum.
Note2: I couldn't bleed the system properly due to the lack of my 10A power supply that i lent and the car is no longer a daily and i have not had the time continue the troubleshooting.

I hope this helps.

[bmrdvr]

O-rings and the internal seals don't last forever particularly within the environment of a car engine, this was bound to happen and will likely continue when in traffic for extended time. If you're having heat issues you have three options: rebuild, buy new, buy MLR rebuilt. You can relocate, but that won't fix overheating issues if your internal seals are tired.

I would say for many/most cases, what you say is true. In my case, there seems to be something off in the specification of the MLR accumulator. My car with the stock setup could idle and run with zero issue going across the Vegas desert at 115F with the AC on zero problems.

The seals on the internal pump and solenoids have all been replaced in the last 3-5 years and I change the SMG fluid fairly regularly just doing various other maintenance tasks involving the intake off or most recently, doing the accumulator or the clutch job a couple years ago. Everything I've done has been preventative on it. It's never leaked or had a problem until I put in this MLR accumulator.

The environment where the pump lives is harsh which impacts longevity/durability; however, a properly functioning system can run at high temps without failure from my personal experience.

[bmrdvr]

I have a 2005 SMG M3 with all original SMG equipment running the CSL SMG Tune. I daily drove my car for years in the Hot Las Vegas summers, temps anywhere from 100-120 degrees and NO issues. So I don't think that's the issue at all. I do have a vented hood, ceramic coated headers and a Spal electric fan to aid in keeping the engine bay temps down. Either this really helps or I'm just very lucky, who knows. Good luck with your SMG issue.

Nah, you have a healthy SMG system obviously anything helps, I don't want to discount that but I agree that these things can take high heat. The wear items such as fluid and o-rings may not last as long but they can certainly run in high heat without fail.