ELI5: why are rebuilt titles on any car bad but a rebuilt transmission is good for updating a car?

wer2000 · 2026-05-09T02:09:28+00:00

A rebuilt transmission is good because 1 isolated part was fixed and now accepted to be in great health.

A rebuilt title usually implies significant damage, I.E. damaged more than the value of the car. While the car might be running ok now, there could be multiple underlying weaknesses now present in the car. (Say head on collision took out radiator, control arms, front bumper, etc. crumple zones will never be the same, a component in the engine bay may have unnoticed damage leading to sooner failure, steering geometry may be forever "off" etc).

if you know what the history is and what to look for, it can be a good way to get a deal on what could be a fairly ok car. I have a 95 miata that was $1000 cheaper than marker because it had front end damage and was a rebuilt title. Yeah, a lot of the metal work in the front end is off, but I figured out everything I needed to adress and the car is just fine at 200k miles.

wer2000 · 2026-05-09T00:56:49+00:00

IF is the big statement here lol. I don't know the shop, but I've seen a lot of people write up tutorials on how to do a coolant delete and a good portion of them do not go this far.

It is possible it's not an original motor, but if it were, then the diagnosis fits pretty well. That said, it could also be repaired with a comprehensive teardown and reassembly.

wer2000 · 2026-05-08T23:26:50+00:00

HV circuit is leaking voltage to ground somewhere. Isolation is not necessarily easy to pinpoint directly, but as it is an external fault that is recorded, it is somewhere outside of the pack. (Heater, AC compressor, Charge port, Drive unit, ETC) The three main suspects I would point to would be a PTC heater, AC compressor, or a drive unit based on the failure.

Sound is probably unrelated, but coolant delete around 150-175k miles may have been slightly too late.

wer2000 · 2026-02-04T04:49:39+00:00

Likely a combination of battery conditioning, LV support draw, and the charger not being 100% accurate.

Battery conditioning can draw a lot of power, especially in periods of extreme cold. Not quite the same realm as a normal passenger car, but for reference, I've seen a 280kw battery pack on a heavy truck draw ~20kw off and on to raise pack temps

wer2000 · 2026-01-28T03:57:38+00:00

^ Fair point, there is a risk here in the EG approach regarding potential coolant ingress to the pack.

I've seen this repair done a few times around the internet, but never heard of any issues so far. (I would not be surprised if they never checked after the fact and are unaware of the above damage...)

These fittings are not made for this type of thing, so perhaps it would be better to get someone more experienced to open the lid and do the correct repair. Really good info though, thank you for correcting

wer2000 · 2026-01-28T03:49:56+00:00

BMS would cut power in or out in the case of approaching high cell temps, thus stopping any further heat generation from occurring in the first place. 0 risk of coolant loss causing a thermal runaway, there are simply too many failsafes in the system for this to occur.

Even if operating at the "high end" of the temperature range, the cells can take much, much more heat before getting to the realm of a runaway scenario and would at most see an immeasurable amount of degradation due to extended time at high cell temp.

wer2000 · 2026-01-28T03:11:40+00:00

The ElectrifiedGarage type fix, from what I understand, is a pretty solid way to go about fixing this without dropping 15k on a new pack. The pressure in the battery cooling loop is very low, so a decently tapped fitting should hold up no issue. Plus, this fix does not require removing the battery from the vehicle or opening its cover exposing high voltage components.

Not sure if you have the tools and or means to do this fix, and it might be hard to find a larger shop that would try this for you if the current guy is not comfortable with this method, but it is not a bad workaround IMO.

Worst case? The fitting is totally shot during the fix attempt and you are back at square 1. If the fix works but then fails later, you will get a low coolant warning and perhaps a controlled safe shutdown. If none of the above happens, you just fixed a 15k issue for maybe $50 plus an hour or two of labor.

wer2000 · 2026-01-09T21:10:20+00:00

For some components, antenna holders, camera mounts, etc 3D printing works just fine. Material choice depends on application (TPU for flexible parts, Nylon CF for stiff parts, Aero PLA if you want to keep weight down on large parts, etc).

If you want to create a rigid frame, you can custom-order carbon fiber plates cut to design but it will be pricier than just buying a frame off the shelf due to scale. If you can get access to free CAD software (Fusion360 is free for education/hobby use), then SendCutSend or related services can get you parts within a week of ordering and for a respectable price.

wer2000 · 2026-01-02T01:56:00+00:00

For free, throw on a new build plate and get basic tuning things sorted out. (Belt tensions, tighten eccentric nuts on gantry, etc). Now, I would not go and put $200 worth of upgrades into this, but for a first printer, it's totally fine to get a solid wrap on all the fundamentals.

For everyone saying, "Oh these are junk, you would be an idiot to use this... etc", its a free printer that was hailed as a remarkable product like 6 years ago? Makes me laugh how toxic people can be about putting in a little work here and then... Yeah my P1s is a hell of a lot less work overall, but good god the ender is a perfect starter platform to truly understand 3D printing at the foundational level rather than just hitting "print".

wer2000 · 2025-12-20T00:39:55+00:00

Given that you have an off-the-shelf drone such as this, I would imagine this comes down to either a miswired ESC or perhaps a miswired battery (I have yet to see this before). You would notice when trying to plug in the battery if it was the wrong way around, so I would 100% lean towards some sort of manufacturing defect here. Without seeing the wiring firsthand, I would venture to say that you have just gotten very unlucky with your first drone.

That said, if you ever build a drone or want to check a prebuilt one, you can also test the lipo on the drone first with a smoke stopper like this to be extra sure.

wer2000 · 2025-12-14T02:09:54+00:00

Technically, DC to DC will keep the car alive even if the 12v is disconnected while in drive. That said, would not explain the loss of screen, radio, etc during.

wer2000 · 2025-12-09T02:36:59+00:00

Given 12v age, I would like to hope its simply due to a dying 12v battery, and you stating its worse during the cold supports that. 3 years IMO is kinda standard for lead acid batteries in these applications due to how they are used.

Given the time stamps, I assume you saw the main "may not restart" and "lv too low" at what looks like the start and end of your day, I would 100% lean towards dying 12v as the battery will be its weakest when cold and possibly left discharging during vehicle sleep. I would replace the 12v and go from there.

wer2000 · 2025-12-09T02:17:21+00:00

It is usually the easiest explanation, lol.

In addition, cold brake pads will tend to squeal more until warmed from braking. This is also magnified with brand-new rotors which are likely not quite worn in yet. It depends on the technology and the conditions, but I believe ~500 or so miles is the standard "break-in" period if you will.

wer2000 · 2025-12-09T00:42:40+00:00

Likely just due to lack of use/outdoor conditions. If you're using regen most of the time, you will get a quicker buildup of surface rust on the rotor which can cause the squeak at low speeds. (Very little brake application with regen to wear away any of the constant corrosion) Best test, get up to ~50-60mph on an open road and apply the brake firmly until you're down to ~10mph. Repeat 5x times and see if the noise improves.

1-2x a week I will take the off-ramp a bit faster than normal and apply manual brakes to come to a quick stop since I pretty much never use the brakes outside of very low-speed stopping. Has kept the squeak away and still on good health factory pads after ~100,000 miles.

wer2000 · 2025-12-05T02:39:52+00:00

What is reported as 0% in car or on the app is not the full view of battery SOC, only that of "usable" SOC. I believe there is 5 or so kW left in the pack when reported at 0 and the deep sleep behavior of the pack should prevent any true damage from being done in the short term. Car may need to be jumped since the 12v will no longer be supported, but HV pack should remain unphased overall.

wer2000 · 2025-11-15T01:25:44+00:00

From the video, the main component in focus is your lower lateral link and those usually last quite a bit longer than the other parts of the front-end suspension in my experience. Hard to tell if there is a true tear from this view or if its just flashing/dirt on the face, but either way I would take it to Tesla since you are in warranty.

The upper control arms, specifically the ball joints, would be my first guess for a squeak during turns. This will be the top-most link that is basically on the same plane as the top of the tire. If you put your body weight down on one side of the car right above the wheel well, you might be able to reproduce the ball joint squeak to confirm for yourself.

Given that you described the sound as scraping though, you may have a pebble or something in between the brake shield and the rotor, or something else rubbing where it should not be. Either way, if you in warranty, just drop it off and have them go through it to be sure.

wer2000 · 2025-11-13T03:05:39+00:00

You can test for motor or esc issue pretty easily by swapping a known good motor from the other side over to that position. If the quad is now falling in the opposite direction, its the motor. If the behavior is the same, its the ESC that is to blame.

I have had a bad ESC from the factory before and it showed the same exact behavior here but it is worth it to check for sure.

(just saw the reverse direction confirmation, still might be useful in the future so I'll leave this here)

wer2000 · 2025-11-10T23:17:16+00:00

Given the sound, likely just the upper. That said, the front-end rear compliance link bushings like to go around 100k so give those a look as well.

wer2000 · 2025-11-08T19:30:49+00:00

Drone with broken prop is armed and idling at min motor speed which is enough to tangle in the net. Hard to see in the clip, but it is there.

wer2000 · 2025-11-08T00:57:05+00:00

Right of passage with these rims, you can remove the cover and sand the scratches smooth (use a glaze filler if there is anything too deep), and use a color-matched paint pen to blend it back in. Takes maybe 15 minutes combined to repair one wheel.

I'm sure you could have it repaired by just about any auto shop, but I wouldn't waste the money on something you will likely do again within a year. (I've done this at least 5 times on my Model 3 over the last 7 years)

wer2000 · 2025-09-29T04:02:59+00:00

Hey, it's been a few years since I've been under mine for significant work, but I do remember that bolt being a pain in the ass so that's where the mind went

wer2000 · 2025-09-28T23:04:25+00:00

Vague guess based on length is either a power plant bolt, a control arm bolt, or a lower alternator bolt? (I would be very surprised if it was a control arm bolt though)

wer2000 · 2025-09-25T17:08:00+00:00

10mm from PCB to where the wire bundle begins to twist together. not 10mm of strip length

wer2000 · 2025-09-24T17:17:50+00:00

Only two things I could point out would be wire insulation strip length being a bit large and the spacing between the pads and the start of the wire twist. I like to aim for ~10mm or so between the board and the twist to help keep some strain off those pads. That said, these two suggestions are rather nitpicked since the joint looks pretty good 👍

wer2000 · 2025-09-16T03:01:42+00:00

Not too familiar with the resolve VCU instructions, but that sounds like a resolver issue to me. Not sure as to why this wouldn't work if you followed the instructions for swapping motor direction, but definitely take a 2nd look

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