OV9

Took mrs mik’s E-Tron for a “larger car task” at the weekend. 25 miles from home on an A-Road the car suddenly sang out some loud warning chimes whilst flashing up “Electrical System Fault – Safely stop vehicle!” followed immediately by a 4WD system fault message, and then a warning related to the drive system, with “Limited Performance Available”.

The vehicle’s definition of “limited performance” actually translated to no performance whatsoever, so I was lucky to be able to pull up safely at the entrance to a rural driveway. Once stopped I decided “actually I’ll move it forward 2m to give the house owner more space to get in and out”. Non. Zero drive.

A quick look underneath suggested some fluid was leaking out towards the front of the car – not a very pleasant smelling one.

Well that’s not looking good.

Called the AA and asked that they just send a flat-bed. Zero drive. 2.7 tonne car. Fluid leaking – it’s not going to be possible to do a roadside repair. Computer said no, so I waited 3hrs for a patrol to arrive, who looked at it, smelt it, and said “I’m not even going to touch it mate” . Another 75mins for a sub-contracted flat bed to recover the car to their holding yard for delivery to the dealership on Monday morning, and mrs mik came to pick me up. In the Evora. A car she has driven for a total of approximately 1.5 miles, when I got it 8 years ago.…erk.

Luckily she, and the Evora, all of it's gearbox ratios, and all originally fitted pistons & valves etc arrived unscathed. Phew.

Audi have now taken a look and declared that the front motor has lost it’s coolant and is now junk. Yes the entire motor unit. A new replacement motor is over £6k. Yikes. The car is 3.5 years old, with 30k on the clock. Now you might suggest that it seems rather crazy that something as simple as a coolant loss would junk the whole motor, but I believe the likely issue is an internal seal failure, so coolant has sloshed around internal electrical bits that should not be exposed to said fluid. It’s a pretty significant “zero warning” failure though.

I’ve always been suspicious of the value of extended manufacturer warranties, but I thank all of the fooks that I decided to proceed with Audi’s offer for an extra year on the E-Tron. Partly ‘cos it was a decent price, and partly ‘cos EV’s are still relatively new tech in the grand scheme of things, hence I thought it was prudent. Phew.

Replacement under extended warranty now confirmed. Unsurprisingly the dealership (who have been excellent so far) don’t have one in stock, but they reckon a new motor should be here on or before Monday. Hire car to cover us until it’s fixed will be delivered to us tomorrow (via Audi).

So we (appear to) have lucked out this time. Some people might suggest however that this doesn’t appear to be a particularly good advert for EV’s. I might agree with them. A quick web search suggests that this is also an issue for Tesla and presumably all other manufacturers who use fluid-cooled drive motors, but thankfully it appears that some companies are starting to offer motor strip down and repair - hopefully avoiding similarly costly component failures writing off aging EV’s in the near future.

Bullet dodged there. I do remember the Model S/X having that problem, which is why they go through so many motors. Not sure if they're really repairable though as when they go they suddenly go and ruin the electronics which seems to be a common theme with EVs.

Perfect timing to put your name down for a new EV Macan. Obviously that would be very tempting.

Yikes Question is, if you took it to a specialist, would it still cost £6k? I've been sleuthing around a few EV forums and noticed some high bills for repairs (but not sure out of context they're any worse than ICE), or whether it's just that we don't have the specialist knowledge yet to repair EV parts, rather than just go the dealer route of outright replacement.

I've been watching the Honda-E FB groups, and someone had a fault on theirs (something to do with the regen braking, I think) which was quoted as £3k+fitting to sort because it's a dealer, so they don't bother to diagnost a part, they just replace an entire unit. These cars are already close to costing peanuts, that repair could potentially write the car off.

Also Evora saves the day

Jeez!

I wonder if they factor these failure rates into the forecasts of lifetime CO2 emissions of EVs...

That's a lot of poop luck on here recently

On the Teslas some people do preventative maintenance to replace the problematic oil/coolant seals in the motors but that is firmly into very hands/experienced DIY territory as I imagine the bill to remove 2 motors, do all the work and refit would be very high. The battery packs also have rubber seals which degrade with age and eventually water seeps in, corrodes and kills the battery. Again removing a 500kg+ high voltage battery is probably not something you want to do at home.
Probably even more of an issue here with specialists now charging close to £200 an hour labour. And EVs depreciating ever more rapidly.

It’s similar to that 1,200,000 mile Model S. It took 4 batteries and 14 motors to get there, pathetic.

Prices will come down but when assemblies with minimal parts are used the failure mode is pretty severe.

I wonder if parts prices will be kept high due to less consumables and less servicing ?

Dave!

A bit concerning really. Would be more understandable if it was doing 40k a year up and down the country, but there can’t be that many conventional cars needing £6k of engine work at 30k and under 4 years old.

I know people will say but it’s cutting edge new technology etc, but come on, electric motors have been around plenty long enough. We have them in our factory running 24 hours a day 7 days a week for 20+ years…

Is the coolant under any sort of maintenance schedule or is it a ‘sealed for life’ system where by life they make it hard for anyone but a main dealer to change and the real life cycle is more like 6 years?

@integrale_evo Yeah, I've been looking into it in a little more detail, and I'm still scratching the surface as opposed to diving deep, but I understand that in order to maximise (particularly continuous) performance manufacturers are deploying motor cooling circuits that go around the stator (sounds absolutely fine), electronic controls (erm - probably ok) and the rotor itself (even inside the rotor).

I'm no expert, but it seems the first two can be "properly separated" (my words) in a similar way to the water jacket around an IC engine. Probably still need a "head gasket" type seal, but nothing that isn't "fixed".

The latter appears to require seals that run on the main shaft of the motor, which doesn't sound like something that's going to last forever.

Presumably this has occured to the designers, and they have set up something to manage any seepage, but it sounds like seal failure causes total loss. Which feels like a fairly big flaw.

This is an Audi motor graphic (2 different motors), but I understand Tesla and others are similar (?)

But are those seals substantially different to those on the shaft of a water pump on an IC engine ?

Sundayjumper wrote: ↑Fri Apr 12, 2024 9:58 am But are those seals substantially different to those on the shaft of a water pump on an IC engine ?

I can't answer with any authority, but I'd guess fundamentally no different. Although I suspect they would be subject to higher temperatures? No idea about pressures.

integrale_evo wrote: ↑Fri Apr 12, 2024 8:56 am Is the coolant under any sort of maintenance schedule or is it a ‘sealed for life’ system where by life they make it hard for anyone but a main dealer to change and the real life cycle is more like 6 years?

There is a resevoir with drain plug in each motor to deal with seepage. Just found this statement

"The front reservoir must be emptied approximately every 20,000 mi (30,000 km) or 2 years during a service. The rear reservoir is replaced at the same intervals. Always follow the instructions in the current service literature."

Assume that means that levels need to be topped up periodically too

Temperature & pressure will go hand in hand to an extent. Assuming the coolant is water-based (?) it’ll stay liquid to quite high temperature as long as the pressure is kept high too.

I was initially assuming the temperature would be similar to an engine but that’s not necessarily true. We’re not trying to maintain efficient combustion here. The aim would be to keep it as low as possible ? I don’t even know what an ideal temperature would be for an electric motor. Close to ambient I guess.

It will probably be a mechanical seal, we have them on all our water pumps, oil pumps etc and they work great.

The issue is the damage caused and the heat cycles things go through. I know they say electric is great, no need to warm through etc but that is such utter bullshit. They don’t change the laws of physics for motors, pumps, engines etc etc

It’s just a new thing for the aftermarket to get around, which they definitely will.

Dave!

integrale_evo wrote: ↑Fri Apr 12, 2024 8:56 am There can’t be that many conventional cars needing £6k of engine work at 30k and under 4 years old.

There's not many EVs that do either.

Undoubtedly that motor could be repaired/refurbed but as with my E46 M3 gearbox the manufacturer replaced it at a cost of nearly 10k. It was 4yr old and done 40k miles.

Might as well add the Model 3 woes to this, its motor doesn’t seem long for this world as I suspect the rear motor has damaged one of its main internal bearings. It has another 25,000 miles of warranty left so hopefully it will grenade soon but as it is Tesla say that “drivetrain noises are part of normal deterioration and not covered by warranty” - the noise is similar to a washing machine on its finally drying cycle as it’s going full speed and it’s almost as loud as a gearbox with straight cut gears.

V8Granite wrote: ↑Fri Apr 12, 2024 10:20 am It will probably be a mechanical seal, we have them on all our water pumps, oil pumps etc and they work great.

Dave is (of course) correct.

Would EV motors not be a better use case for waterless coolant?

Swervin_Mervin wrote: ↑Fri Apr 12, 2024 2:31 pm Would EV motors not be a better use case for waterless coolant?

I think they have a flash point that is quite low so would probably be a big fire risk.

Dave!