SMG Relocation Alternatives?

[///M3RIC]

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.

[oceansize]

IMO if you aren't pushing the car to its absolute limits then any SMG problem more than likely isn't heat related. I could certainly be wrong. My car had 95k miles on it when I did the relocation. Overheating in hot humid Tennessee was never an issue. I did my relocation to simply make access easier, admittedly the thought of less heat on something as expensive as the hydraulic unit was appealing even if I don't view it as necessary. I think, no matter what, the pump will need to be rebuilt/replaced. Its electro mechanical plus hydraulics that run under high pressure and temperature. It will fail. I rebuilt my pump simply because I didn't like the boogeyman that is SMG existing. I wanted to know how it worked so when there is a problem it wouldn't seem so daunting.

The problem would then really be:

1. The motor (easy enough), not working efficiently enough to create pressure in a timely manner.
2. Accumulator's inability to hold pressure thus causing the pump to work harder.
3. The seals and o-rings are no longer sealing and again the pump is working harder .

Accumulator can be tested using some versions of INPA and all of DIS. How well your pump holds pressure can be measured in INPA. Seals and o-rings can be be bought and replaced. You can swap the fluid out for Burkhart's higher viscosity version which supposedly decreases time to create pressure by as much as 25%. Not sure I buy that degree of improvement but I use it and don't have any problems. It has been noted that it isn't recommended for relocated pumps.

As for relocation I've had zero issues and I mean that, none, if I had them I'd say so, but there are others on this board, who definitely know what they're doing, and they have a lot of bleed issues post relocation. Pump siting higher on the car, different orientation, etc. I've noticed, anecdotally, that during the relocation many people's (including mine) clutch slave cylinder fails, so perhaps factor that cost in.

In the end I guess a heat shield or tape couldn't hurt but I wouldn't think of it as a real solution, which you alluded to. Something probably needs replacing internally (seals,o-rings) or externally (accumulator, motor)

[Slideways]

Unless you are planning on putting thousands of miles on it a year, just use it as-is if it is currently working. Change the SMG fluid, flush the clutch hydraulic fluid and it should be good to go.

[TramRam]

So good to see fresh SMG discussion! I'm looking into the relocation of my pump too. I live amongst the SMG haters & like you, I love my SMG and want to optimize its life & function!

Is possible that you or someone reading here might have researched this system & knows by having used INPA or a similarly capable diagnostic tool, the hydraulic fluid temperatures with the hydraulic pump relocated to the drug bin compared to when the pump in its original location? I've read in just one post that it will typically 20 Deg cooler on the bin but I understood that that value was not the fluid temp, but that of the bin compartment (ambient) versus the ambient temp in the original mount location. I've done the ducting using a boat bilge fan with a thermo switch but the benefits seemed small. With additional line length, thus a greater heat sync along with a greater volume of fluid, it seems like a no- brainer to do the relocation!
Is there an ohm test for the blue sensor on the hydraulic. pump body. I believe it reads temperature (?). Also, is a pressure sensor on there that can also be ohmed to verify its accuracy? Since mine was rebuilt years ago, I've always felt that that blue one was reading differently than the one it replaced.

Thanks in advance!

TramRam

[0-60motorsports]

Here is my thread on the SMG relocation pump:

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/172094-vince-s-smg-pump-relocation-bracket-information-and-feeler

I did that relocation by extending the harness and then ordering lines from one of the ex members on M3F. Those lines started leaking in a year so I had my own made from somewhere in Florida Which are much better but werent cheap LOL. And that's about it. Never rebuilt the original pump etc. as I had under 38k miles on it then. Since the lines leaked i just replaced the SMG pump with a 4K miles one i had lying around, nothing was wrong with my original pump.

[Obioban]

If you're not tracking the car, seems like a pointless mod to me. Really need to be putting a lot of heat into it for this to be beneficial.

[PowerSax]

I agree with using it where it is. If you have ever used hydraulic equipment, they get very hot. Hoses, fluids, all of it. Back when the SMG relocation wasn't a thing, neither was changing the Pentosin fluid. You don't even have to change it all. Just turkey baster the fluid out of the reservoir and replace with fresh fluid on a yearly basis.
Good to go!

[TramRam]

So... should I assume that no one, who has done the relocation, has looked to see what their hydraulic fluid tempts are pre & post move? I just wonder what criteria was used to justify the relocation? The conditions are easily measurable with INPA! Right now I'm ducting air from the lowest area of my bumper, thru the air box, where my bilge fan is located, with 2.5 in. racing brake ducting directed at the aluminum block area of the pump. I've got a digital gage that reads 2 thermocouples, (TCs) at once with one TC in the cooling duct & the other reading the ambient temperature in the vicinity of the pump. It allows me to see fan ON & fan OFF tempts in each area. I WISH I could have attached one TC directly to one of the hydraulic lines at the aluminum block but obviously, getting to that area requires removal of the PITA intake manifold. Anyway, that's my story. I'll be glad to relocate the pump...I would just like more data than I have, or have read, before pulling the trigger.

Also: Anyone know the bench ohm test values for the temp & pressure sensors?

Thanks in advance!

[eacmen]

So... should I assume that no one, who has done the relocation, has looked to see what their hydraulic fluid tempts are pre & post move? I just wonder what criteria was used to justify the relocation? The conditions are easily measurable with INPA! Right now I'm ducting air from the lowest area of my bumper, thru the air box, where my bilge fan is located, with 2.5 in. racing brake ducting directed at the aluminum block area of the pump. I've got a digital gage that reads 2 thermocouples, (TCs) at once with one TC in the cooling duct & the other reading the ambient temperature in the vicinity of the pump. It allows me to see fan ON & fan OFF tempts in each area. I WISH I could have attached one TC directly to one of the hydraulic lines at the aluminum block but obviously, getting to that area requires removal of the PITA intake manifold. Anyway, that's my story. I'll be glad to relocate the pump...I would just like more data than I have, or have read, before pulling the trigger.

Also: Anyone know the bench ohm test values for the temp & pressure sensors?

Thanks in advance!

I relocated to allow for quick pump swaps at the track. Worked great last year, pump died second session saturday. Sunday morning was able to swap a spare pump and bleed it in about 45 mins.

[oceansize]

So... should I assume that no one, who has done the relocation, has looked to see what their hydraulic fluid tempts are pre & post move? I just wonder what criteria was used to justify the relocation? The conditions are easily measurable with INPA! Right now I'm ducting air from the lowest area of my bumper, thru the air box, where my bilge fan is located, with 2.5 in. racing brake ducting directed at the aluminum block area of the pump. I've got a digital gage that reads 2 thermocouples, (TCs) at once with one TC in the cooling duct & the other reading the ambient temperature in the vicinity of the pump. It allows me to see fan ON & fan OFF tempts in each area. I WISH I could have attached one TC directly to one of the hydraulic lines at the aluminum block but obviously, getting to that area requires removal of the PITA intake manifold. Anyway, that's my story. I'll be glad to relocate the pump...I would just like more data than I have, or have read, before pulling the trigger.

Also: Anyone know the bench ohm test values for the temp & pressure sensors?

Thanks in advance!

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.

[TramRam]

Like you Ocean, I really like the improved access to such a potentially finicky unit! That alone is almost enough for me to just do it. I've been in the military jet engine development business all of my post college career and LOVE DATA...IMO, there can never be too much it. It tells stories and so much can be learned about instrumented systems by gathering and using it appropriately. QUESTIONS: Can the solenoids be tested in place? Are they mount grounded? Do you know if the hydraulic fluid constantly circulates such that it includes the contents in the reservoir?? Any reality to the advice to NOT use the Burkhart fluid in a relocated pump? I read that on M3Cutters or some other SMG posting. Didn't make sense to me. With longer lines, Id WANT a more responsive fluid if in fact that's what the fluid actually does.

Thanks again for the chat!

[0-60motorsports]

So... should I assume that no one, who has done the relocation, has looked to see what their hydraulic fluid tempts are pre & post move? I just wonder what criteria was used to justify the relocation? The conditions are easily measurable with INPA! Right now I'm ducting air from the lowest area of my bumper, thru the air box, where my bilge fan is located, with 2.5 in. racing brake ducting directed at the aluminum block area of the pump. I've got a digital gage that reads 2 thermocouples, (TCs) at once with one TC in the cooling duct & the other reading the ambient temperature in the vicinity of the pump. It allows me to see fan ON & fan OFF tempts in each area. I WISH I could have attached one TC directly to one of the hydraulic lines at the aluminum block but obviously, getting to that area requires removal of the PITA intake manifold. Anyway, that's my story. I'll be glad to relocate the pump...I would just like more data than I have, or have read, before pulling the trigger.

Also: Anyone know the bench ohm test values for the temp & pressure sensors?

Thanks in advance!

I did and I'm sure I posted them up. After relocation I saw a drop of at least 10c in the fluid temps on a hot day in Bahrain. The moving of the SMG pump is a must in my opinion and will prolong the life of the pump. Also changing the pump out is a 5 min job when it's relocated to the passenger engine bin area 🤣

[MacCube]

I can't remember where I read this at, but the only complaint about using the Burkhart fluid is in colder climates where the fluid becomes more resistant to flow at extremely low temperatures. Also, has anyone considered the advantages of running the hydraulic lines directly to each of the actuators from the hydraulic unit which would bypass connecting to the stock hydraulic lines? The lines would need to be made-up in different lengths and different fittings at the actuator connection end. The stock hydraulic have too many places where air can become trapped causing problems with bleeding the system. The new flexible lines could be routed along the top of the transmission and bell housing in a way that would eliminate or at least reduce those places. When I "get around to" relocating my pump this is what I'm going to try. I've already talked to MLR Engineering about it and he didn't see any problems. Just a thought.

[0-60motorsports]

I can't remember where I read this at, but the only complaint about using the Burkhart fluid is in colder climates where the fluid becomes more resistant to flow at extremely low temperatures. Also, has anyone considered the advantages of running the hydraulic lines directly to each of the actuators from the hydraulic unit which would bypass connecting to the stock hydraulic lines? The lines would need to be made-up in different lengths and different fittings at the actuator connection end. The stock hydraulic have too many places where air can become trapped causing problems with bleeding the system. The new flexible lines could be routed along the top of the transmission and bell housing in a way that would eliminate or at least reduce those places. When I "get around to" relocating my pump this is what I'm going to try. I've already talked to MLR Engineering about it and he didn't see any problems. Just a thought.

I never had a problem bleeding the system. It's always good practice to do it a few times and monitor the reservoir for bubbles but yeah never had any issues.

Let us know how that idea works out.

[TramRam]

I did and I'm sure I posted them up. After relocation I saw a drop of at least 10c in the fluid temps on a hot day in Bahrain. The moving of the SMG pump is a must in my opinion and will prolong the life of the pump. Also changing the pump out is a 5 min job when it's relocated to the passenger engine bin area 🤣

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