BMW SMG ISSUES!

[@tonymontana897]

It's the heat soak into the hydro unit that kills them. BMW stupidly moved the hydro unit from the front just behind the headlight on the E36 to the side of the engine block on the E46 and so began the downward spiral of quality control for BMW's. I still have my E36 m3 with SMG I and it is still running faultlessly for the 16 years I've owned it and for the previous owners.

[@cadilphpottinger4093]

@@tonymontana897 what is the hydro unit cand can I move it to a cooler area

[@tonymontana897]

@@cadilphpottinger4093 It's essentially the SMG pump/reservoir. I'm not too familiar with the layout of the E46 engine bay, but I have heard that some guys did relocate it, but where to, I cannot tell you. I wonder if BMW did try to mitigate the heat with a heat shield of sorts, but I doubt it. I think they knew what they were doing when they put it there so they could be assured of many a return customer to their service dept with failed hydro units. At 3K a pop it's good business right ??

[@TheM3smg]

Can you do the smg to manual conversion?

[@itsimty]

@@TheM3smg yes a lot of people go this way

[@shant]

What if the car doesnt go into N to start the car.. the display shows you moving to N but it does not actually move to N . I had to mess with it for 5 minutes, turning ignition on and off until it finally went to N allowing me to crank (Have new salmon relay already fitted) .. could it be the gear selector sensor ?

[@itsimty]

@@shant without diagnosing the vehicle physically it’s difficult to say but sounds like a hydraulic pressure issue

[@shant]

@itsimty thanks that's what I was thinking too. If that is the case, just the acumilator needs replacing? (Also I had the pump relocated to the drug bin couple months ago, new fluid and proper bleed)

[@itsimty]

@ like I said can’t say for sure as the car is not with me but sounds like a hydraulic issue

[@shant]

@@itsimty I understand, im in the states. thank you.

[@walesroofingservices4572]

Got a problem at the moment it’s not selecting any gear at all I got a code for hydraulic pressure I clear the code and it works fine but code will come straight back on and won’t let me select again no warning lights any ideas

[@itsimty]

@@walesroofingservices4572 need to look at the Smg system, unfortunately these are quite problematic

[@walesroofingservices4572]

@@itsimty it’s had gear position sensor done around 2 years ago since haveing that done it’s been fine up untill now going to try the relay when that comes just eliminate cheepiest first and hope for the best lol but loss of pressure do you have any ideas where to start looking can’t see any obvious leaks and coming Up now on computer with hydraulic unit

[@itsimty]

@@walesroofingservices4572 if you have pressure drop it could be a leaking accumulator or failed seals within the hydraulic unit, I hope you resolve it, if you struggle give @gtechmotorworks a call

[@walesroofingservices4572]

@@itsimty well it’s funny how you say that as I re set that with the computer and then it let me select gears fine then the pressure will drop again I re set it and it’s fine so whatever it is it needs sorting going to have another look on the computer tommorow but I will keep you all updated and thanks I’ll have a try first if I fail I’ll give them a ring 👍

[@walesroofingservices4572]

@@itsimty failing that if it turns out to be the pump I’m going manual any recommendations would be appreciated

[@cadilphpottinger4093]

I have a 2004 645is BMW with a smg transmission which nature's when it gets hot . After driving for 30 minutes to 45 minutes then I have to wait until it cools down to select and drive again. What could be the issues

[@itsimty]

sounds like a temperature sensor issue, or could have internal pressure drop.

[@aviationodyssey1892]

Good info man, thank you

[@itsimty]

Glad you found it interesting Thank you for the watch

[@aviationodyssey1892]

@@itsimty I cannot start the engine of my E46 M3 SMG and change the gears (SMG cog light). So it looks like clutch could be worn out?

[@itsimty]

@@aviationodyssey1892 you need to connect a diagnostic machine and check the hydraulic clutch gap, most of the time if the clutch is worn the car will not start

[@itsimty]

Thank you

[@RaviSuta]

Not selling me the e46 this haha