Leak onto floor from rear of car

[surfrasch]

hey folks, my 2018 Model 3 has developed a slight leak, dropping from under the trunk in back. I've attached a few photos here. Here's what I know so far:

1. I can't see the color of the fluid.
2. It has an oily feel to the touch.
3. When I pull the car up the driveway, you can see the drip drip drip as I'm entering the garage, .....so it seems to be dripping more when I'm driving, then it seems to slow down when parked in the garage.
4. The underbody shield is damp (see the pictures), so it's something above the shield. Also whatever it is, is flowing backwards while I'm driving and making the rest of the underbody shield damp.

I've got Tesla remote service coming Friday to check it out, but my expectation is I'll have to hit a service center. Has anyone seen this before?

Model 3 LR dual motor, about 45k miles. Car has been solid as a rock until this.

 

[Soul Surfer]

I'm guessing, coolant, if it has an oily feel.

 

[surfrasch]

I'm guessing, coolant, if it has an oily feel.

yeah I'm thinking the same, battery coolant. I'm suspecting that's not a good thing. I'm wondering how much has to leak before I get some type of low pressure warning or something like this related to battery management?

 

[Soul Surfer]

yeah I'm thinking the same, battery coolant. I'm suspecting that's not a good thing. I'm wondering how much has to leak before I get some type of low pressure warning or something like this related to battery management?

Rich Rebuilds did a video about the repair. If you're under warranty, then do that IMHO.

 

[P3dStealth]

That's probably ATF-9 from the rear motor.
See if you can peak at the rear motor from the wheel. The axel seals might be leaking.

 

[surfrasch]

thanks guys, will try.....

 

[surfrasch]

just fyi, no easy way to see the rear motor from the wheel side, there are barriers in there. Probably the only way to see it is to remove that damp underbody shield, but I'd prefer to have Tesla to that.

 

[KenC]

Yeah, since you have someone coming, they can do it. If you didn't and had rhino ramps, you could just back it up on the ramps, then undo the 8 hex bolts holding that panel up and look at the motor seal.

 

[BigNick]

Put down some white paper towels or a white cardboard box where you park, the next time it leaks it should be easier to determine the fluid color.
Blue would indicate coolant because washer fluid won't be coming from that far back.
ATF should have a red tinge to it unless it's burnt to hell.

 

[surfrasch]

Put down some white paper towels or a white cardboard box where you park, the next time it leaks it should be easier to determine the fluid color.
Blue would indicate coolant because washer fluid won't be coming from that far back.
ATF should have a red tinge to it unless it's burnt to hell.

good point, like duhh.....just put down some white paper towel....though interestingly it doesn't seem to leak much when the car is sitting there. Appears to leak a lot when driving.....so something that is pressurized when driving perhaps?

 

[surfrasch]

okay my wife just drove in the garage, and I was able to see it dripping onto the paper towel. Looks gray to black when it's on the towel, but I suspect there's a blue tint to it that I can't easily see. Definitely no red tint. Here's a good pic where you can see a drip about to drop. Most likely coolant?

 

[el-guapin]

^^ Kind of looks like axle grease. Maybe a torn axle boot?

 

[P3dStealth]

Well... This is what the tesla coolant leak looks like. Just a coincidence that my Tesla just started leaking coolant today. It's bright green.

 

[P3dStealth]

Hey I was wrong. That green stuff in my picture is UV dye in my refrigerant to look for leaks. I didn't realize Tesla had used it to leak check my AC system after doing something else. They must have spilled it. No big deal.

I've used dye myself before but only for oil leaks so you don't get to see it clean like that on the floor.

 

[stopcrazypp]

Hey I was wrong. That green stuff in my picture is UV dye in my refrigerant to look for leaks. I didn't realize Tesla had used it to leak check my AC system after doing something else. They must have spilled it. No big deal.

I've used dye myself before but only for oil leaks so you don't get to see it clean like that on the floor.

If you have a heat pump car, there is a TSB to replace the sensors and they need to flush the refrigerant to do that, so they may have used that as part of the service.

 

[surfrasch]

just a follow up, Tesla remote service came and jacked up the car.....removed the original underbody shield which was pretty dirty on the top side....full of sand and oil (we live on a dirt road). They claim there's an oil filter for the rear drive, and that was leaking. They couldn't figure out if it was cracked or leaking at the seal. I couldn't get up there to check it out, not allowed to get under the car.....and they replaced the shield with a brand new one. So basically I couldn't see the problem myself.

The tech told me he had to contact his manager to understand what to do next, but I hadn't heard back in four days so put in another service request at the service center on Tuesday (2 days ago)....specifically pointing out the problem and asking if the car is okay to drive. The earliest appointment I could get (Peabody MA center) was in three weeks. Texted them again today asking for a response and an earlier appointment, crickets.

We shall see....

 

[KenC]

just a follow up, Tesla remote service came and jacked up the car.....removed the original underbody shield which was pretty dirty on the top side....full of sand and oil (we live on a dirt road). They claim there's an oil filter for the rear drive, and that was leaking. They couldn't figure out if it was cracked or leaking at the seal. I couldn't get up there to check it out, not allowed to get under the car.....and they replaced the shield with a brand new one. So basically I couldn't see the problem myself.

The tech told me he had to contact his manager to understand what to do next, but I hadn't heard back in four days so put in another service request at the service center on Tuesday (2 days ago)....specifically pointing out the problem and asking if the car is okay to drive. The earliest appointment I could get (Peabody MA center) was in three weeks. Texted them again today asking for a response and an earlier appointment, crickets.

We shall see....

Oh, Peabody, I have an appt there in 3 weeks.

Yep, the motors have an oil filter, which could leak if not screwed on correctly, or if cracked, etc. Here's a pic of mine when I got an alignment, they removed the shields, and the tech let me walk around and take pics. Not Tesla, but my local tire shop. I think this is the rear motor, but both motors have oil filters on them.

 

[surfrasch]

Oh, Peabody, I have an appt there in 3 weeks.

Yep, the motors have an oil filter, which could leak if not screwed on correctly, or if cracked, etc. Here's a pic of mine when I got an alignment, they removed the shields, and the tech let me walk around and take pics. Not Tesla, but my local tire shop. I think this is the rear motor, but both motors have oil filters on them.
View attachment 839811

ahh wow, thanks!.....yep looks like an oil filter, interesting that it's not on a schedule to get replaced?

 

[rpiotro]

ahh wow, thanks!.....yep looks like an oil filter, interesting that it's not on a schedule to get replaced?

Why? As this is a sealed unit there is no way additional contaminants could get in and any debris from wear would stabilize pretty quickly. Still, maybe at 100K miles it might not be a bad idea.

 

[P3dStealth]

It's been well know since the first 3s that there is an oil filter. The drive units are filled with ATF-9. It's believed the filter is to get the metal contaminants from wear and extend the fluid life. There has been some argument if you should change the oil. It's no longer in the manual but some have claimed it was in 2018. Also if your motor makes a pop Tesla will change your oil. It's not uncommon for car enthusiast to change transmission and differential fluids early. It's also not uncommon for other people to never change transmission and differential fluids.

Not sure if I am ever going to change it. You should get Tesla to change yours though because you don't know how much you lost.

Oil Change

I read somewhere that it was a 100,000 mile replacement since it's just gear lube. Gear oil without the thermal stress related aging you see in a 6+ gear tranny of a ICE car should last *a lot* longer than 100k miles in a EV like a fixed single gear Tesla.... Heck - many ICE transmission...

teslamotorsclub.com

Gear Oil Change (Fail)

www.teslaownersonline.com

Replacement Drive Unit fluid (atf-9?)

Interesting🤔.......have you noticed any increase in efficiency from the new fluid or cooler temps? Nope the cooler gave me a little bit more time before thermal cut kicks in. It’s an expensive $1500 for the second hotlap

teslamotorsclub.com