Drive unit coolant leak, tear down/test/repair (hopefully)

[stang_shane]

Sadly, the issue did pop up again. I finally decided to purchase a used DU and have been waiting to get the firmware pushed.. It's been quite the struggle as the car seems to not want to keep the 12V charged when it needs new firmware, so every time that Phil has tried to connect to the car, it's offline.

Life is always hectic, but I do have plans of taking it apart again to determine, hopefully, the root cause. I've also bought some grey RTV instead of the red RTV, hoping to get a better seal when I put it back together. I can't imagine there is much pressure going through the coolant system (I've also removed the o-ring from the coolant cap) so I'm really surprised that the leak came back.

 

[laurynas]

Mine was actually leaking on motor side. Looking for new motor as it is probably not worth to fixing.

 

[bart_dood]

Sadly, the issue did pop up again. I finally decided to purchase a used DU and have been waiting to get the firmware pushed.. It's been quite the struggle as the car seems to not want to keep the 12V charged when it needs new firmware, so every time that Phil has tried to connect to the car, it's offline.

Life is always hectic, but I do have plans of taking it apart again to determine, hopefully, the root cause. I've also bought some grey RTV instead of the red RTV, hoping to get a better seal when I put it back together. I can't imagine there is much pressure going through the coolant system (I've also removed the o-ring from the coolant cap) so I'm really surprised that the leak came back.

Bummer, yes let us know the outcome. I can imagine at some point in the future I'll need to do this but hopefully by then all the wear parts will be more readily available.

 

[stang_shane]

Just to give an update, as the saga has finally ended. I installed a new (used) DU and was working with Phil to get the firmware pushed. The car wouldn't stay on the network and also wasn't accepting the update either when Phil was able to see it connected. I eventually worked through some of my contacts at Tesla and after they tried to push firmware remotely (which also failed), I drove the car to the SC and they got everything lined out. There were still issues once the car was there and driving to the SC with all the errors was a bit nerve racking, but I'm glad to be able to drive the car again. Ultimately, I think I'm having the eMMC errors as well, which lead to the failed firmware push attempts from Phil and Tesla remotely. Tesla suggested replacing the MCU for $2700.

Just FYI, I was only able to drive after disconnecting and reconnecting the 12V battery. This, for some reason, made the car forget that everything wasn't matching and if I quickly put the car in drive, it would let me drive. I didn't test how long I could actually wait, but it was enough time to reconnect the battery, close it all up, back out of the garage and then drive the 25 miles to the SC. Hoping this helps someone else that may need to drive for whatever reason.

 

[zwede]

Thanks for the update. You mentioned earlier that the SC refused to push firmware if you replaced the DU yourself. How did you make them change their minds?

 

[Lasttoy]

This might sound dumb, try to get in touch with Rich, at Richrebuilds in Salem Masss. He has alot of parts, also has videos. He helped one time. Google him.

 

[gigstorm]

There are people who can do an emmc replacement for much cheaper. DM if you want to pursue that method. They clone the flash and resolder a much more durable unit. 200 USD was the last quote I got.

 

[stang_shane]

I don't think I was able to change anyone's mind at Tesla. I honestly believe that they are still new enough that even the employees are unsure what they are allowed or able to do on owner repairs. I started talking to some of the people I knew that worked at the SC and then ultimately just scheduled the appointment. I had no assurance that they would actually do the firmware push before I took the car there.

I've talked to Rich a little about the car and he was able to point me in the direction for some of the non-Tesla support from Phil.

Gigstorm - message coming your way!

 

[mesikaru]

I just bought out of warranty 2015 MB B-class Electric with Tesla drive unit and only 4000 km. I'm getting quite nervous reading all the leaking issues from the forums. Looking at the pictures of the construction it seems inevitable that sooner or later the leak will occur and ruin the motor or drive unit or both. Is there any preventive measures that I could take to keep the risk minimum?

 

[stang_shane]

I would say there is nothing that you can do to avoid the issue, if it's going to happen. I tried to fix 2x and was unsuccessful. I'll ultimately try again, but I don't plan on putting it back in my car.

No need to worry, some motors have no issues at all. Others have various issue. It's just a game of chance.

 

[andyjmfrank]

Shane, i would love to speak with you as we have the exact same problem. Been hunting for help for a while. Please email me [email protected]. i would like to exchange phone numbers and will gladly paypal you for your help. thank you

 

[ZC_1995]

Similar issue here with my out of warranty Model S! Of course Tesla wants to swap out the drive unit ($6k just for the unit plus labor and misc parts) rather than rebuilding it in the shop. If @stang_shane or @andyjmfrank or others might be up for helping me troubleshoot I'd appreciate it!

 

[MP3Mike]

Of course Tesla wants to swap out the drive unit ($6k just for the unit plus labor and misc parts) rather than rebuilding it in the shop.

One of the rebuilders charges $4k, or more to rebuild your drive unit, and I'm pretty sure they don't give you a 4-year/50k mile warranty like Tesla does. So it isn't too far from the mark. (Though I wish they could bring the price down some more.)

 

[ZC_1995]

One of the rebuilders charges $4k, or more to rebuild your drive unit, and I'm pretty sure they don't give you a 4-year/50k mile warranty like Tesla does. So it isn't too far from the mark. (Though I wish they could bring the price down some more.)

The all-in price from Tesla is right around $8k for the drive unit including parts and labor. I'm in the St. Louis area and don't know of any shops within a day's drive that could do the work for $4k. Makes sense that there'd be more shops like that in CA where there are more Teslas versus the middle of the country. Looks like I might end up dropping it myself and trying to rebuild it.

 

[DiyEvRepair]

Has anyone attempted a driveunit inverter DIY fix on a model 3 or Y before? I am having HV isolation issue in rear inverter, and I suspect it is also due to a coolant leak.

Thanks!

 

[DiyEvRepair]

Actually looks like on 3 and Y it is not possible for the coolant to leak into the inverter logic area - the 2 areas are on different parts of the inverter housing (pretty smart design actually) so I will probably need to replace the inverter unit...