7 year review of my SMG (from clunk to no clunk)

[eacmen]

This is why I think something isn't optimal since I rebuilt my pump at the time of my relocation. This is the first I've heard of Burkhart not recommending there fluid for relocations and yes I talked directly to them two years ago. Not saying things don't change but I will talk to them again this week and see what they tell me.

👍

Please see the bottom of this page for their relocation kit:

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

[oceansize]

There is much variance between the condition and quality of the smg pump. A pump in very good condition can likely overcome the pressure drop that may be experienced with the longer hoses.

In either situation burkhart does not recommend their own fluid for the relocated pump because it will not reach their target hot viscosity value. If it works for you that’s great but may not work for everyone.

This is why I think something isn't optimal since I rebuilt my pump at the time of my relocation. This is the first I've heard of Burkhart not recommending there fluid for relocations and yes I talked directly to them two years ago. Not saying things don't change but I will talk to them again this week and see what they tell me.

[eacmen]

Possible but:

1. I'm relocated.
2. I've been using Burkhart fluid for two years.
3. I don't throw random codes and never have.
4. I drive my car year round from really cold to really hot.

I think something else is not optimal.

There is much variance between the condition and quality of the smg pump. A pump in very good condition can likely overcome the pressure drop that may be experienced with the longer hoses.

In either situation burkhart does not recommend their own fluid for the relocated pump because it will not reach their target hot viscosity value. If it works for you that’s great but may not work for everyone.

[oceansize]

When you lengthen the hose you introduce the possibility of pressure drop depending on the velocity of the fluid. That combined with thicker burkhart oil is likely leading to issues described when combined with the relocation and cold weather.

Only the CH11 fluid should be used with the relocation harness. The burkhart fluid should only be used for SMG pumps in their original position as its thicker viscosity is meant to help in situations where the SMG pump gets too hot where the CH11 becomes less effective.

Possible but:

1. I'm relocated.
2. I've been using Burkhart fluid for two years.
3. I don't throw random codes and never have.
4. I drive my car year round from really cold to really hot.

I think something else is not optimal.

[eacmen]

When you lengthen the hose you introduce the possibility of pressure drop depending on the velocity of the fluid. That combined with thicker burkhart oil is likely leading to issues described when combined with the relocation and cold weather.

Only the CH11 fluid should be used with the relocation harness. The burkhart fluid should only be used for SMG pumps in their original position as its thicker viscosity is meant to help in situations where the SMG pump gets too hot where the CH11 becomes less effective.

Also bleeding and adapting the smg unit in the relocation position can be difficult. The unit must be oriented in its original position during bleeding before being mounted in the drug bin.

[oceansize]

As soon as it warmed up above 50 degrees here I stopped getting the code. Unfortunately we had a pretty hot day on Friday at 85 degrees and sitting in traffic I got another code. After that on low speed shifts from 1st and second I got a groaning sound. It shifted fine at normal driving speeds and was completely fine after is cooled down.

All if this makes me think it is the Burkart fluid. Seems like it has an operating range of like 50 to 75. I had no SMG issues prior to the relocation. I’m going to switch back to the OE fluid and see if that helps.

Let us know how it goes as I've been running Burkhart for a couple years here in TN where it gets really hot and humid come summer and have not experienced any issues.

What was the code?

Also, groaning can be air in the system.

[robgill]

I am getting the same code you are, to truly know if your slave cylinder is bad, you need to check the values in INPA for the clutch operation (i do t remember the actual value name atm) if this value is fluctuating it means the sensor within the slave cylinder is bad. If i recall correctly this value represents the distance it needs to travel, this is the clutch bite point during adaptation. In my case its a new cylinder and i still get the code.

You can also repair the unit, they do sell the compression metal bracket/ring that retains the rod to the cylinder, its the same repair kit as the non smg cylinder. Only difference is the sensor, if it goes bad the unit is done.

hope this helps.

As soon as it warmed up above 50 degrees here I stopped getting the code. Unfortunately we had a pretty hot day on Friday at 85 degrees and sitting in traffic I got another code. After that on low speed shifts from 1st and second I got a groaning sound. It shifted fine at normal driving speeds and was completely fine after is cooled down.

All if this makes me think it is the Burkart fluid. Seems like it has an operating range of like 50 to 75. I had no SMG issues prior to the relocation. I’m going to switch back to the OE fluid and see if that helps.

[Irhase46m3]

I am getting the same code you are, to truly know if your slave cylinder is bad, you need to check the values in INPA for the clutch operation (i do t remember the actual value name atm) if this value is fluctuating it means the sensor within the slave cylinder is bad. If i recall correctly this value represents the distance it needs to travel, this is the clutch bite point during adaptation. In my case its a new cylinder and i still get the code.

You can also repair the unit, they do sell the compression metal bracket/ring that retains the rod to the cylinder, its the same repair kit as the non smg cylinder. Only difference is the sensor, if it goes bad the unit is done.

hope this helps.

[oceansize]

Yeah I am running the Burkhart relo and fluid. Also all of my starts have been cold weather (40 and below). oceansize it could be that the PLCD sensor you mention about is more sensitive to the cold weather and viscosity with age? I'm going to let it prime more and hope for warmer weather before I replace the slave cylinder.

If I did change the fluid is there a specific chf11s you all recommend? Looks like OE BMW is Pentosin.

Correct fluid. As for the sensor that is why I was asking the other guys what codes they get. If you are all getting the same code and don't have any issues then I would definitely hold off on replacing the Clutch Slave. I haven't experienced this issue so I can't comment for sure on a potential cause. When my clutch slave went out it simply died with no warning and that was that.

If you do replace the clutch slave do not compress the rod before install. There is a clip, or whatever, inside the clutch slave that will break after install and first usage allowing compression/decompression. Having that clip broken before you install makes it hard to align the rod to the dimple on the the plate that receives it.

[zivagolee]

If you guys get the cog light there should be codes. What are they?

I also have relocated my SMG pump to the drug bin and use Burkhart fluid. I do not get the cog light randomly under any circumstances (I had my car parked outside in rural PA two months ago for a week with the temp regularly hitting the teens and low twenties).

I always get code 59. I have changed out my clutch and throwout bearing already. The clutch slave should be easy to change.. just needs a flush which I will do anyway. I will use the standard Pentosin CHF-11.

[robgill]

Yeah I am running the Burkhart relo and fluid. Also all of my starts have been cold weather (40 and below). oceansize it could be that the PLCD sensor you mention above is more sensitive to the cold weather and viscosity with age? I'm going to let it prime more and hope for warmer weather before I replace the slave cylinder.

If I did change the fluid is there a specific chf11s you all recommend? Looks like OE BMW is Pentosin.

[oceansize]

If you guys get the cog light there should be codes. What are they?

I also have relocated my SMG pump to the drug bin and use Burkhart fluid. I do not get the cog light randomly under any circumstances (I had my car parked outside in rural PA two months ago for a week with the temp regularly hitting the teens and low twenties).

[zivagolee]

Hi There - I too have the same COG light, only when cold start though (actual temp outside needs to be below 50 F) in order for this to happen.

a few questions, are you using the oem fluid chf11s to operate the pump?

are you letting the pump fully prime before you go to start the car?

in my case i can avoid the COG by doing the following:

let pump prime fully (turning the key to second position and not pressing the break pedal, until pump finishes priming. Once done priming, i press the brake pedal and start the car, this usually gets rid of the COG until it warms up.

Also, i have the burkhart engineering relocation kit and also their special smg pump oil, which in my case causes this COG when cold vs the chf11s fuild. Since i live in california it doesnt usually get that cold to warrant the change to chf11s so i just live with this process.

i suggest you try this before going out and replacing the slave cylinder.

good luck!

I get the COG light on especially cold mornings with the Burkhart fluid (I also did the relocation and live in SF). I will switch back to chf11 fluid as recommended by Burkhart soon.

[Irhase46m3]

Hi There - I too have the same COG light, only when cold start though (actual temp outside needs to be below 50 F) in order for this to happen.

a few questions, are you using the oem fluid chf11s to operate the pump?

are you letting the pump fully prime before you go to start the car?

in my case i can avoid the COG by doing the following:

let pump prime fully (turning the key to second position and not pressing the break pedal, until pump finishes priming. Once done priming, i press the brake pedal and start the car, this usually gets rid of the COG until it warms up.

Also, i have the burkhart engineering relocation kit and also their special smg pump oil, which in my case causes this COG when cold vs the chf11s fuild. Since i live in california it doesnt usually get that cold to warrant the change to chf11s so i just live with this process.

i suggest you try this before going out and replacing the slave cylinder.

good luck!

[robgill]

This is most commonly the clutch slave cylinder due to the PLCD sensor which is not replaceable on its own (it is embedded into the clutch slave). Fortunately it is an easy job but it will require bleeding the system after replacement plus running adaptations. There is a difference between the SMG clutch slave and manual clutch slave. The SMG is more expensive of course.

https://www.ecstuning.com/b-genuine-...r/21522229841/

Thanks for the quick reply, I'll give the the slave cylinder a look. Thus continues the trend that if I didn't replace it during the full restoration it's now likely to break 😆.