SMG Relocation Alternatives?

[TramRam]

Hello,

I am new to this forum, but I was a long-time member of the old m3forum. I’ve been out of the m3 and off the forums since about 2015. My car has basically been sitting for years and I’m beginning the process of bringing it back to life. There were some issues before I stored it away and after sitting for so long, I’m sure there are more.

While my car didn’t have any pressing SMG issues at the time, I was then, and especially now am planning on performing some preventative maintenance and modifications. Since I’ve been off the forums the SMG to manual conversion has become much more popular and approachable and while I recognize the many benefits of going that route, one of my favorite aspects of the car is the SMG. So, I intend on keeping it and doing what I can to improve the reliability.

Last I was active on the forums, the relocation of the SMG pump was either not yet an option or was not very popular. It seems to be the go-to SMG modification nowadays. I’m on the fence about performing the relocation due to the work and parts it would require. Also, I have an ’02 with the mk20, MLR does sell a kit for my situation, but it seems like it would be very crammed. I’ve been looking into alternatives; there is the resistor, which is more of a band-aid than a solution, there also have been a few owners that have created ducting to funnel air to the pump, I’m not sure if this has proved beneficial or not.

My basic understanding of the issue is the pump is too close to the engine resulting in overheating. Short term, it overheats the temp sensor causing the transmission to drop into neutral. Long term, it results in expedited wear and subsequent failure. The relocation offers a solution to these issues and makes the pump more accessible, but before I commit to that project, I’m searching for alternatives. Are there any additional options to what I’ve mentioned so far (6mt swap, resistor, ducting, relocation)?

A possible option I’ve been curious about is using some form of heat shield. Has anyone tried this? This could be as elaborate as fabricating a shield that mounts between pump and engine, or using a section of flexible heatshield on the block side of the pump, or completely wrapping the pump in heatshield, or spray-on heat shield, etc.

Let me know if anyone has tried it or what you think.

My thoughts: I've been day dreaming of how to go about understanding how the air in the engine bay moves. I've always thought that by knowing, the heat around the pump can be better addressed. Does it flow high to low, front to rear etc. When I did the Build Journal tune, I requested the fan speed curve setting since I live in 'hot as hell' South Florida thinking it couldn't hurt. I don't track this car. But it SEEMED like I started getting the slipping-into-neutral & yellow cog on 85+Deg. days if I'd been running anything like 80 or 90, followed by getting into stop-n -go or waiting in line at a gas station. I started thinking that the fan was possibly blasting the hot radiator discharge back along the sides of the engine and bathing the hydraulic pump with that heat at a now higher velocity bc of the BJ Tune! That's when I started thinking about how the uderhood air flows. I considered a physical shield but I felt that to be risking making something worse until I understood the airflow better. I thought that a 'curtain' of positive flowing air from my bilge fan would reduce the radiant heat from the engine block, (IF THAT'S THE SOURCE), and maybe also block the radiator discharge heat with the cooler, higher velocity air being blown over the pump body. I thought that by not fully understanding the air movement & adding physical block might be shooting myself in the foot! I remain convinced that there needs to be effective air OUTFLOW which in this case is under the car. So then I started thinking about a draw fan, again to ensure airflow AWAY from the engine bay. THEN I learned about pump relocation to the drug bin! SH*T! Longer hydraulic lines & an extended harness, BOOM! Aside from the cost of the kit & the time to do it, or have it done, it seems like a no-brainer! Significantly improved access, for troubleshooting & anything else! The longer hydraulic lines by default will radiate fluid heat by themselves! Knowing a bit about hydraulics & the effects of pumping and high system pressures makes for heat on the coldest of days p once things are up & running! I think that it's nothing but plusses once it's installed properly!

Cheers!

Good luck on your journey!

[///M3RIC]

I appreciate all the responses, input, and discussion. I think I’m going to acquire a low mileage pump to rebuild with fresh gaskets, maybe an MLR pump motor too, and swap that into the stock location. I live in Portland, Oregon and I don’t track the car so high temps aren’t often a concern.

If dropping into neutral becomes an issue in the future I’ll perform the relocation then.

As for bleeding the system, that is performed using INPA, correct?

[SUPREM3///]

I want to find someone who's done the trunk relocation, which MLR offers but I'm not sure it's been installed on any car that sees the street.

I haven't done a relo yet, think I'll wait until I have a rebuilt pump to swap in simultaneously, but I'd mostly do it for the easier access.

I appreciate all the responses, input, and discussion. I think I’m going to acquire a low mileage pump to rebuild with fresh gaskets, maybe an MLR pump motor too, and swap that into the stock location. I live in Portland, Oregon and I don’t track the car so high temps aren’t often a concern.

If dropping into neutral becomes an issue in the future I’ll perform the relocation then.

As for bleeding the system, that is performed using INPA, correct?

Correct, it will be in the shift + options under "Special Tests"

[0-60motorsports]

Thanks for your response 0-60!

1- In your country, do you simply use the Burkhart fluid exclusively or are your pump swaps done often enough for the stock fluid to run well?

2- What fails in your pumps that you NEED to swap them so often?

3- I've assumed that like with a brake fluid reservoir, the hydraulic pump's reservoir needs also to be higher than the system it feeds. Is that also the case with this project?

4- With your swapping, assuming that you, or someone is rebuilding the one that is removed, can you recommend a rebuild kit with parts of superior materials over other kits? (I used to do my brake master cylinders and brake calipers & more recently rebuilt my VANOS so I THINK I could handle the hydraulic pump. Doing my VANOS was rewarding!

It's great to have you guys as a resource!

Thank you

1. Maybe used the Burkhart fluid on one car. Otherwise all of them we are using oe fluid.

2. No idea as we didn't replace seals on any of them, just motor and it was fine afterwards and then when something else went wrong the customers went for a 6MT swap.

3. That's what I have seen so I went with the original placement of components and that is why the SMG Pump relocation bracket was built by Vince to have the CSL reservoir sitting on top.

4. I would use Burkhart or MLR as usual. I haven't done the replacement of internal seals till today but it's not hard at all and would love to do it on my original SMG pump one day.

[TramRam]

1. Maybe used the Burkhart fluid on one car. Otherwise all of them we are using oe fluid.

2. No idea as we didn't replace seals on any of them, just motor and it was fine afterwards and then when something else went wrong the customers went for a 6MT swap.

3. That's what I have seen so I went with the original placement of components and that is why the SMG Pump relocation bracket was built by Vince to have the CSL reservoir sitting on top.

4. I would use Burkhart or MLR as usual. I haven't done the replacement of internal seals till today but it's not hard at all and would love to do it on my original SMG pump one day.

Thanks for your feedback 0-60!

[SUPREM3///]

1. Maybe used the Burkhart fluid on one car. Otherwise all of them we are using oe fluid.

2. No idea as we didn't replace seals on any of them, just motor and it was fine afterwards and then when something else went wrong the customers went for a 6MT swap.

3. That's what I have seen so I went with the original placement of components and that is why the SMG Pump relocation bracket was built by Vince to have the CSL reservoir sitting on top.

4. I would use Burkhart or MLR as usual. I haven't done the replacement of internal seals till today but it's not hard at all and would love to do it on my original SMG pump one day.

Is there anywhere to grab one of Vince's brackets? I recall seeing older posts about making them available but I'm curious if that is a current option?

Is the Burkhart bracket the best one on the market now?

[0-60motorsports]

Is there anywhere to grab one of Vince's brackets? I recall seeing older posts about making them available but I'm curious if that is a current option?

Is the Burkhart bracket the best one on the market now?

I would message him directly on the forums or FB. Otherwise your choice is Burkhart.

Vince designed mine with my Radium catch can in mind so it fits perfectly.

[MacCube]

MLR Engineering offers a relocation bracket for cars with or without ABS module.

https://mlreng.com/products/smg-pump-relocation-bracket?variant=31461142429783

[0-60motorsports]

MLR Engineering offers a relocation bracket for cars with or without ABS module.

https://mlreng.com/products/smg-pump...31461142429783

There you go, another option.

The thing i didn't notice on their site are the extended hoses.

https://burkhart-engineering.com/shop/bmw/bmw-m/bmw-m3/verlaengerungshydraulikleitungen-hydraulikeinheit-smg-2-passend-fuer-e46-m3-inkl-csl-bmw/

[SUPREM3///]

That's the first time I've seen a picture of the MLR bracket, it used to just be the MLR logo. Glad you posted that

[MacCube]

The Burkhart bracket has a bracket on it to mount the hydraulic expansion tank. The bracket that MLR offers does not appear to have that by the photo they show. But that bracket shown may be designed for cars with the ABS module. MRL will also custom fabricate the hydraulic lines to any length and any fittings needed. Remember that if you're going to connect the hydraulic lines to the metal ones on the car, that fitting needs to be female. Just sayin'.

[TramRam]

It definitely runs cooler but it has been years since I did my relocation and logged temps so don't want to give a number that isn't true (I can't remember and evidently I didn't bother to log it anywhere). For me there was no real criteria other than I didn't like having to remove the intake to get at it. So when I made up my mind to take it apart I then decided to relocate. If you aren't having problems leave it alone until you are unless you're like me and simply want to.

For the solenoids you can test them all as they all won't be bad so if you have one outlier it will be evident. Then apply 12v and if get the click your good. Pressure sensor if bad will typically read a value of -1 in INPA.

MacCube, is the orientation of the hyd. unit critical to good bleeding & overall function or is it not a concern?

Also, I read somewhere that when the unit is relocated, to be prepared to replace the clutch actuator. Why might that be?

TIA

[oceansize]

MacCube, is the orientation of the hyd. unit critical to good bleeding & overall function or is it not a concern?
Also, I read somewhere that when the unit is relocated, to be prepared to replace the clutch actuator. Why might that be?
TIA

After relocation when bleeding, if the pump's accumulator is vertical then orientate the pump so that the accumulator is horizontal with the pump's red snap ring (where the CSL reservoir connects) pointing upwards. Disconnect the reservoir hose from the pump. When I disconnected the hose I saw three large air bubbles exit from the pump within a few seconds. At that point I had the bled the system approximately 10 times. Reconnect the CSL hose and bleed again. After successfully bleeding you can orientate the accumulator back to the vertical position.

I don't have any issues while running day to day. Anecdotally, the clutch slave cylinder seems to fail when the system is completely depressurized, I would guess age, mileage, heat, etc. have all played all role.

[TramRam]

Oceansize , thx for your response. I've been away until now.

Isn't the relative position of the fluid reservoir, to where it connects to the hydraulic pump, critical to ensuring that there's a gravity loaded column of fluid in the supply tube that connects them to keep air out of the pump?

Is the fluid in the reservoir there just as reserve or does it somehow circulate?

You indicate that you run the bleed sequence a bunch of times before you're done. What tells you when you're done? I thought INPA says when it's done so I've never done more.

Is running an occasional bleeding sequence a good thing?

TIA, TramRam

[oceansize]

Oceansize , thx for your response. I've been away until now.

Isn't the relative position of the fluid reservoir, to where it connects to the hydraulic pump, critical to ensuring that there's a gravity loaded column of fluid in the supply tube that connects them to keep air out of the pump?

Is the fluid in the reservoir there just as reserve or does it somehow circulate?

You indicate that you run the bleed sequence a bunch of times before you're done. What tells you when you're done? I thought INPA says when it's done so I've never done more.

Is running an occasional bleeding sequence a good thing?

TIA, TramRam

On disassembly and reassembly air enters and gets stuck in various places. Each person will fight their battles with air. If you’re lucky it’s a small battle, if not then you will have to do the various things I’ve laid out. I bled many times to really make sure all the air was out. I’ve not had an issue or had to revisit my SMG system since the rebuild and relocation. Been thousands of miles now.

The reservoir is just a holding tank. The motor and gears in the hydraulic unit circulate the fluid and pull from the reservoir. My reservoir sits roughly level with the pump now but the hose from the reservoir still sits higher than the connection to the pump. Gravity is still in play.