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Thanks for reading and your will to help via a reply, please read this entire message before suggesting to ditch the SMG in favor of 6 spd conversion because I am a disabled driver using hand controls so rely on an automatic acting gearbox to avoid using a torque converted automatic. Ok, if yer still with me, here is what’s going on and conditions I may be running under. To be honest, I want to set this thing up to run in extreme conditions so I can feel confident to compete in an endurance scenario. I Live and mostly run events in Texas so could easily be circa or over 100 deg ambient temp.

Car: 2003 M3 coupe SMG, relatively high mileage track only uses and moderately modified, supposed to have come with a “new SMG pump“ 1 yr ago. As far as I know there’s no tranny software upgrade.

Engine and relative mods: bone stock S54 with CSF rad, CSF oil cooler kit, and, due to previous SMG module overheating and per watching a YouTube vid, ran a 2.25“ hose from the removed driving light hole in the bumper cover and pointed at the module to attempt to “cool”, or at least move the air to prevent heat buildup.

Result after last nights evening runs at COTA (ambient temp 95 - 90 for the last run): About halfway through the sessions the little sprocket light on the dash would illuminate, hoping that it had just cleared the given temp threshold to trigger the light and that my new air ducting would keep it operating as demanded, it did not. It began to shift up in gears on it’s own, found myself in 5th or 6th very early in the back straight, and a couple times I think it even killed the engine, but surprisingly dumped the clutch and restarted. In an earlier run, I was coming off the track into my garage spot and it wouldn’t downshift to 1st, and even when it cooled down still insisted to start in 2nd, so I did, gently.

Yes, I do drive this car very hard and have high expectations, however, I don’t feel like it should be failing just because of the aforementioned. I would appreciate hearing from someone who has experience with these to see what my next steps may be. I even considered putting an aluminum cup halfway down the cooling duct and filling it with dry ice to help cool the ducted air. Not even sure how long that would last, but you can see how desperate I’m getting. Of course I could get a newer car with the DSG but I like the E46 platform and engine, so......

Thx much!!
 

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E30M3 Race F10 535 R1150Rt M Coupe
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I hear ya'. Had a customer with similar issues of oil temps getting too hot and the problematic issues of coolant/oil temps on the E46 chassis. BTW the same engine in a M Coupe (older or newer) have less issues. It's the rather large bumper size of the E46 chassis that prohibits much of the needed airflow for cooling. That's why many who track their cars do what you have done AND install an aftermarket hood (Sh!##y solution) that vents upwards right behind the radiator to let more air through.

Back to your issue. I've often wondered about the possibility of adding in a cooling loop to the pressurized/return lines of the SMG system to allow for the oil to circulate to the nose, go through a fined cooler and than back to the pump?
Bleeding completely would be tough, but once done just might solve your immediate issues?
 

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Have you looked into the SMG relocation kits? I forget who sells them. It moves to pump into the empty upper rightside cubby


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I've driven COTA plenty of times without overheating issues. I've driven Cresson MSR in 102 degree heat and a 110 heat index a few weeks ago with no overheating issues.

I have stock s54 internals and a stock smg. It has a small tune and euro headers. I run slicks and XP20 carbotech pads. The car gets driven hard.

A functional, stock m3 engine and transmission are completely capable of running at speed without overheating.

Overheating issues arise when the fan clutch stops working well or the ducting around the front of the radiator and bumper are not aligned well.

Your issue will be from a part problem and not because you're too fast or the car can't handle it.
 

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Discussion Starter #5
I hear ya'. Had a customer with similar issues of oil temps getting too hot and the problematic issues of coolant/oil temps on the E46 chassis. BTW the same engine in a M Coupe (older or newer) have less issues. It's the rather large bumper size of the E46 chassis that prohibits much of the needed airflow for cooling. That's why many who track their cars do what you have done AND install an aftermarket hood (Sh!##y solution) that vents upwards right behind the radiator to let more air through.

Back to your issue. I've often wondered about the possibility of adding in a cooling loop to the pressurized/return lines of the SMG system to allow for the oil to circulate to the nose, go through a fined cooler and than back to the pump?
Bleeding completely would be tough, but once done just might solve your immediate issues?

Thanks so much for your reply and input. Since I have ducted air to it and that's not helping, I do believe that the tranny temp heating the case and surrounding elements could be the culprit. The tranny gets up to about 235 deg F during a hard run, and while it may be able to operate at that temp, perhaps the hydraulic fluid, or pump it serving can't. We just yesterday discussed adding a separate cooler for it but there was a concern about the pressures remaining to spec and consistent so the sensors aren't tripped and effect operation. Got another reply about a pump relocating kit, so will be looking into that. Thx again.
 

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I've driven COTA plenty of times without overheating issues. I've driven Cresson MSR in 102 degree heat and a 110 heat index a few weeks ago with no overheating issues.

I have stock s54 internals and a stock smg. It has a small tune and euro headers. I run slicks and XP20 carbotech pads. The car gets driven hard.

A functional, stock m3 engine and transmission are completely capable of running at speed without overheating.

Overheating issues arise when the fan clutch stops working well or the ducting around the front of the radiator and bumper are not aligned well.

Your issue will be from a part problem and not because you're too fast or the car can't handle it.
Haha, got it, and thanks for your humbling comment, I probably need it. Mine is a high mileage car and have no idea how well it was taken care of before I got it so..... At first he engine was overheating, addressed that, and the tranny was not, but it's the SMG pump and hydraulic fluid within specifically that was illuminating the sprocket warning light and then beginning to malfunction.

Just got the car 9 mos ago from NC, was moderately prepared and it'd clearly hit a barrier or something because the carbon front bumper was crunched and missing a brake duct. Also discovered the factory cooling fan was gone so addressed those with an elect fan, so no fan clutch present, but was still getting hot on long runs and found that the grill ducting aft of the kidneys was also missing, so adding that with the high flow elect fan fore of the radiator and acceptable tolerances were achieved.

Been looking for a used GTR style carbon fiber bonnet just because I like it, and I can see how the venting of hot gasses wasn't just for the cool factor but can actually can help, and reading another reply here does confirm that so looks like I'll either cut the current one or replace it with a vented one.

Glad to hear yours is working well and if it decides not to, reach out and I will probably have a few proven fixes by then. Thanks again.
 
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