brainhouston
Active Member
i believe that depends on the state of the car/components
when car is off, DU will just have dashes
i think charger only shows temp when its charging...
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when car is off, DU will just have dashes
i think charger only shows temp when its charging...
asavage
Member
Not to confuse, but there is another source of accel-only noise, that is not a bearing: it's "Contactor Squeal", on the early vehicles. See Tesla Note TN-13-16-002 R1. I had this for a few months, after the HV battery was replaced under warranty. It went away. It was variable "pitch" for me, and would change as I pressed or released the accel pedal.
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A leaking rotor coolant seal impacts the outer rotor bearing only, as the only place for the coolant to go is through the bearing, watering-down the lubricant on its way to the stator cavity. If your noise is truly a rotor bearing, it's likely to be just the one. But the coolant does damage further on, including lowering the stator winding's HV isolation resistance (covered extensively above in the last couple of pages), and eventually making its way to the power electronics on the inverter side of the LDU.
Bottom line: it almost certainly should have the rotor cover pulled for inspection, which is a subframe drop on a Model S.
I'm going to do the delete for sure when the supply of caps come in and replace the rotor bearings at the very minimum. A tip I picked up somewhere - when you pull your speed sensor, don't use the blue shop paper towels to wipe it. Instead, use a white paper towel from the kitchen. This will allow you to see if whatever is on it is blue (coolant).
My comment about the 'cool' coolant is specific to the coolant going into the top of the gearbox. In the original design, it is presumably very hot since it went through the rotor tube first. In the delete design, the coolant going to the top of the gearbox will be at the system's operating temperature. The 'cool' coolant will still mix with the hot coolant from the stator and inverter before exiting the LDU and the gearbox fluid sloshing around on the gear side of the heat exchanger is constantly mixed but the aggregate temperature of the gearbox and the coolant exiting the LDU will be cooler after the delete than it was before.
asavage
Member
asavage
Member
I have the LDU rotor temp monitor working after a fashion. In my driveway, car sat overnight:
I went on a 30 mile drive, about half of which was hilly and on cruise control @ 57 MPH (~95 kph):
The highest I saw was 182°F, doing a few full-accel sprints of 20-45 MPH around town.
This is a lot lower than I expected. I don't know if these numbers are plausible.
I went on a 30 mile drive, about half of which was hilly and on cruise control @ 57 MPH (~95 kph):
The highest I saw was 182°F, doing a few full-accel sprints of 20-45 MPH around town.
This is a lot lower than I expected. I don't know if these numbers are plausible.
Thanks for that: my car has always had that squeal if I accelerate hard. One single, high pitched tone which changed to a lower pitch. I had assumed it was the inverter, now I know.
asavage
Member
On the MS/X, the contactors are closer to the rear; on the RAV4 EV, they're in the front in the battery pack, and as a driver you're basically sitting on top of them, so the noise is pretty clear.
In my case, I'm not certain that my noise was the contactors, but I haven't heard it again after the first two months after the battery replacement. And I pretty much only heard it on three hills on my daily commute even then. But it wasn't subtle.
In my case, I'm not certain that my noise was the contactors, but I haven't heard it again after the first two months after the battery replacement. And I pretty much only heard it on three hills on my daily commute even then. But it wasn't subtle.
CarelessCustom
Member
Thanks for the thread, it helped a lot. I did the conversion on my car if anyone is interested to watch a little long video.
Gtech
Active Member
So, wanted to post some extra data points since we also placed a rotor cap delete plug last night.
T19 is 2019 right? This car is high mileage btw.
So before we did the operation we wanted to check for signs of coolant.
Sensor: grease but no coolant
Greasy inverter case, not a really good sign.
Then we checked stator cap and HV cable cap:
Clean
LDU HV cap. Moisture, but definitely no coolant just water (taste tested it) few hours later it was already evaporated so interesting.
Connectors looked like crap.
Then we decided to do iso test LDU, B+, B- and stator windings all where the same (4.7-4.8 Mohm)
So at this point no coolant under stator cap but moisture under HV cable cap.
We decided to pull LDU and check inverter housing for moisture and reluctor wheel cavity.
So, reluctor wheel was dry so very happy to see that and when we pulled inverter casing we found this:
Dry stator connections, there is some white residue but it was dry for sure
So no moisture at all but a lot of sticky slime between the seal and housing? It looks like moisture on image but it is definitely not. Also some sticky slime on the bottom of the inverter housing. Unfortunately I don't have a picture of that.
So cleaned everything and placed the cap.
So you have to grind away the whole pipe, also the circlip that holds the insert in place because otherwise the cap won't fit. Hope it will stay in place
Put everything back, added coolant and turned on coolant bleeding procedure.
Still not sure about the moisture on the HV cap and HV cables but think it's a good thing we pulled the inverter casing. We cleaned the HV cables and placed some very little grease on them (on top and above the O ring)
T19 is 2019 right? This car is high mileage btw.
So before we did the operation we wanted to check for signs of coolant.
Sensor: grease but no coolant
Greasy inverter case, not a really good sign.
Then we checked stator cap and HV cable cap:
Clean
LDU HV cap. Moisture, but definitely no coolant just water (taste tested it) few hours later it was already evaporated so interesting.
Connectors looked like crap.
Then we decided to do iso test LDU, B+, B- and stator windings all where the same (4.7-4.8 Mohm)
So at this point no coolant under stator cap but moisture under HV cable cap.
We decided to pull LDU and check inverter housing for moisture and reluctor wheel cavity.
So, reluctor wheel was dry so very happy to see that and when we pulled inverter casing we found this:
Dry stator connections, there is some white residue but it was dry for sure
So no moisture at all but a lot of sticky slime between the seal and housing? It looks like moisture on image but it is definitely not. Also some sticky slime on the bottom of the inverter housing. Unfortunately I don't have a picture of that.
So cleaned everything and placed the cap.
So you have to grind away the whole pipe, also the circlip that holds the insert in place because otherwise the cap won't fit. Hope it will stay in place
Put everything back, added coolant and turned on coolant bleeding procedure.
Still not sure about the moisture on the HV cap and HV cables but think it's a good thing we pulled the inverter casing. We cleaned the HV cables and placed some very little grease on them (on top and above the O ring)
blodg1
Member
Unfortunately this damage was done by the SC. I have seen it several times but they still haven't changed the procedure. This happens because of the yanking force when the LDU is replaced and failure to replace the cable O-rings. The proper way to remove the LDU on pre-refresh is the bring it down with the HV harness by disconnecting at the HVJB. I see this often when the drive unit is the second or third for the vehicle. Many people are forced to pay out of pocket for this harness on warranty LDU replacement because these aren't part of that warranty.
brainhouston
Active Member
this is interesting
when i looked at mine, it had same exact greasy spot, scared me a bit that it was coolant sipping out
i guess its a good sign for me
Gtech
Active Member
Yeah it was definitely some of the greasy transparent jelly that made its way out, maybe they use it as a non conductive grease to make the housing slide easily over the big O ring and also against moisture intrusion but that's just guessingthis is interesting
when i looked at mine, it had same exact greasy spot, scared me a bit that it was coolant sipping out
i guess its a good sign for me
Mine did as well. I didn't think much of it at the time but when I read that @Gtech said it was a bad sign I got a little disappointed.
Gtech
Active Member
That was actually my first reaction when I saw the inverter casing but few hours later when removed inverter housing it turned out to be no harm so my first conclusion was incorrect. Not sure if that is in all cases but just sharing my own experience.
Think it's important before doing the coolant delete to not only check speed sensor but also measure iso, check both caps for moisture to get an indication what is going on. Stator cap can be removed while LDU is still in the car
Think it's important before doing the coolant delete to not only check speed sensor but also measure iso, check both caps for moisture to get an indication what is going on. Stator cap can be removed while LDU is still in the car
Grease on Speed Sensor
Thats packed with some serious grease. Its pretty obvious Tesla original/reman LDU rotor shaft+seal are packed with grease for some reason (maybe to help install?) I've been thinking triple lip packed with grease might last longer (original early LDU that didn't get swapped out due to early clunk and bearing noises seems to last the longest : 7-8+ years and some even over 150k miles)
Yours is a Reman (R1), all the remans I've seen had single black lip PTFE seal. Was yours single lip also?
If it was triple lip seal, was there grease in the 2 chambers between the 3 lips? Everyone's LDU removed used triple lip pictures are blurry. Likely as lips are black and probably packed with dark grease.
Moisture In Inverter
B+ B- cables has an o-ring that sits on the bottom of the tunnel to prevent moisture ingress. But poor orientation as condensation will just sit and receive gravity assist. Perhaps the moisture inside B+ B- cover just came from ingress through the o-ring?
Does the car live in a high moisture environment in Netherland?
Wetness on Inverter Casing
Have seen pics like this a few times and have always thought coolant but sounds like maybe not the case.
If you have water moisture ingress via B+ B- cable tunnel and park on ever the slightest grade tilted down on driver side, then condensed water in inverter will exit the inverter case rubber seam. The rubber belt won't hold back the moisture. I know a LDU rebuild that cut the coolant channel o-rings under the inverter (hard to reinstall inverter) leaked coolant came right out of the inverter case seam.
Sticky Slime
My 2017 reman LDU inverter casing was perfect clean outside (had coolant terrarium on inside due to seal leak towards connector end due to slightest grade tilted down on passenger side)
There are 2 sources of "slime" inside the LDU : One is the jelly covering all the IGBTs on the 3x phase boards. The other is inside the CANBUS connector plexiglass housing encasing the interface board. If you squeeze that housing, jelly will move around. Presumably these are to prevent moisture condensation from settling on top of key electronics such as IGBTs and CANBUS interface.
I wonder if your CANBUS housing jelly got washed out? Leaked out? or Tesla decided to dump more Jelly/slime in later inverter assembly for additional condensation damage prevention?
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asavage
Member
The cable glands leak rainwater into the inverter, it's a common issue. Be sure to test the HV Iso on those cable, use 500v and you can test from the inverter end (ie at the cables as shown above) or at the Rear HVJB under the rear seat, with the cables connected or disconnected from the LDU.
Low Iso on those two cables has been reported a number of times.
Nice test instrument
You are fortunate in that you appear to have "only" water on the inverter side.
Yeah, clear viscous goop. I think it's a thermal transfer compound Tesla uses to mount the IGBTs, but I could be wrong. Traces have been present on the lower inverter cover on both LDUs I've had open.
So cleaned everything and placed the cap.
So you have to grind away the whole pipe, also the circlip that holds the insert in place because otherwise the cap won't fit. Hope it will stay in place
Note here for others following along: it's pretty likely that a groove or channel needs to be ground into the side of the casting to allow proper coolant flow out to the flyover tube. There's not much clearance between a typical aluminum cap and the casting when the taper tube is ground to flush. Perhaps you ground yours below flush? Or you ground/cut a groove?
My groove is a bit fancier than it needs to be, because I happen to have a hobby mill/drill, but any groove that is approximately the area of the flyover tube is sufficient:
If you don't replace them, then I'd put lots of grease or lots of RTV on the outside where they insert into the inverter cover, after assembly. Road "salt" is really hard on them in this design.
Hank42
Legacy Supporter
So.. just bought a salvage reman Rev q ldu to replace my utterly damaged non reman Rev q ldu. The reman one is clean , but I noticed this one
had a hole in the speed sensor area where the non reman Rev q does not. What's that all about?
had a hole in the speed sensor area where the non reman Rev q does not. What's that all about?
Tesla use to put hole there to equalize pressure as rotor slides sides ways ever so slightly with those 2 bevel washers on the outer bearing. I guess the theory was the seal/reluctor wheel chamber will get pressure change when this happens thus a hole equalizes against the remaining LDU air cavity. Then it was decided it wasn't necessary.
Most rebuilders thought this hole allowed propagation of aerosolized coolant leak (agitated by the reluctor wheel) travel by air into stator and then into inverter. Mine had this hole and I sealed it with JB weld following the changes to the later LDUs. Removal of this hole seems to have occurred at Rev Q or afterwards.
The quick answer is... probably it doesn't really matter after rotor coolant delete to eliminate seal leak. Hole or no hole will be fine.
asavage
Member
What Howard said.
For more info, see Johan's excellent video @ 105:
For more info, see Johan's excellent video @ 105:
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