It's sort of scary if the result of a jammed louver (or broken louver motor, etc.) is compressor damage that results in supermanifold damage before the problem is detected and the HVAC system shuts down.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Recent heat pump failures - software issue?
- Thread starter BR666T
- Start date
I could probably answer this myself by looking at the modes in that video but I'm feeling lazy so I'll ask here. If the kind of failure (VCFRONT_a531) we're talking about has happened and the compressor is functioning in 'degraded' mode or not functioning at all, does the software try and use one of the other modes to generate heat for either cabin or SC preconditioning purposes?
I'm waiting on parts still for my SC visit and the cabin heat still works, albeit it seems like at reduced capacity.
Did you guys check out Quick Bandit - Model Y license plate mount | 1975creations ? I went with that one. It seems to mostly sit up above the grill so hoping no similar problems.
I am not sure. I didn't get an opportunity to talk to the service advisor. I had that mount for almost 16 months. It is possible that the bolts were too long. But very similar to the ones in that Etsy listing.
Here is my theory about what is happening (just a wild guess -- I have zero evidence that this is what is actually occurring):
- There is absolutely no way Tesla could have produced cars with heating systems can't operate when it gets below -20°C. Tesla certainly tests their vehicles in all different temperatures, probably all the way down to at least -40°C.
- Tesla likely does their cold weather testing either in a cold chamber, or outdoors when it's actually below -20°C, and they do it on a closed track. As a result of the type of weather they're targeting, there is either no precipitation or very little precipitation when they do their testing, and few or no cars ahead of the test vehicle kicking up snow and ice.
- In an effort to reduce part count, Tesla connected the louver AND the valve that controls the flow of the glycol to the same motor and same actuator. Why have two separate motors for both components when you can only have one? Well, turns out this wasn't such a good idea. If the louver jams due to being iced up, the valve that causes glycol to bypass the radiator also gets jammed, and cannot close off the radiator path. As a result, glycol continues to flow through the radiator when it shouldn't. This in turn causes the glycol to become extremely cold and the coolant in turn becomes extremely cold, which eventually causes liquid coolant to be fed into the compressor, damaging the compressor. The damage to the compressor in turn causes metal shavings to enter the supermanifold, and as a result, both need to be replaced.
- Tesla failed to put a heater on the louver to melt ice and ensure that it will always be able to close
- In the real world, their system has trouble when precipitation (especially supercooled raindrops) and snow and ice kicked up by other vehicles accumulates on the louver, which jams it and radiator bypass valve in the open position. I drove my other car (Outlander PHEV) over Donner Summit last month and by the time I got to the other side, the entire front of my vehicle was coated in about 1/8-1/4" of ice from supercooled raindrops and water kicked up by vehicles in front of me hitting the front of the car! That's the sort of thing that could jam a louver in the open position, and while it wasn't actually cold enough (-3°C) that the system would have had to close it, this could cause issues if it got much colder later on and I didn't get down to lower elevations.
- The orientation of the radiator behind the louver, with its upper surface exposed, makes ice preferentially accumulate on that side because any water droplets that blow in through the open louver will accumulate on the radiator by gravity and then freeze on the radiator's surface, which makes the radiator even colder than it would otherwise be.
I had front lower louvers freeze and immobilized on my 2017 Volt in 2017. Got check Engine light then read the error code. So Tesla isn't the first to not engineer any precautionary measures to stop winter. I have to say I am very disappointed. I usually dismiss the "Engineered for California" but they really deserve it for this one.
How did GM solve the louver icing issues? Heaters?
The other issue I have is the orientation of the radiator. If it's the condenser of an air conditioning system, its orientation doesn't really matter. Any water that accumulates on it will run off. But if it can function as an evaporator/chiller, it should be oriented such that any water that blows in through the louver does not tend to collect on it (perhaps it should be on top of the cavity behind the louver, and there should be drain holes on the bottom of the cavity, for example). Otherwise you'll just have to defrost it more frequently than otherwise necessary especially if it is 3°C and raining and the temperature of the radiator below freezing. And of course, they should have heaters at the bottom of that cavity to make sure that ice doesn't block the drain hole.
I just don't see how Tesla could have missed very cold weather testing. They know that these cars will be used in all different types of climates. But overlooking what happens if the louver jams due to it being iced up seems like something that is plausible.
The radiators are only for the glycol loops, there is no air sourced evaporator/condenser. (They use a liquid cooled condenser to transfer the heat between the refrigerant and the glycol coolant.) You can see the Model S Plaid setup in this Munro video.
I think the idea of that is that it shouldn't freeze up as easily.
If the glycol is below freezing, the radiator will be below freezing, and ice will form on it. If the dew point of the air is such that condensation forms on the radiator, there's no way to avoid ice build up; you have to just defrost it periodically. But water drops that blow in through the open louver are another matter, and Tesla has oriented the radiator such that any drop that blows in will stick to the radiator's surface and, if the radiator is below freezing, will form ice. Why they didn't design it so that the air enters through the louver and then has to go up through the radiator so that gravity can separate out the water drops, I'm not sure. This is probably most problematic when the air temperature outside is just above freezing and the radiator is just below freezing, but you can also get issues with snow blowing in and sticking to the surface of the radiator too. The way it's designed it just seems like they'll require far more defrost cycles than they should otherwise need.
From what I can see the air does go up, but the radiators are angled fairly heavily which gives them room for a bigger radiator, and frunk tub.
When I look in through my front louver, I can see that the radiator is at a steep angle. It's more horizontal than vertical. The lower end of the radiator is toward the front, and the upper end is toward the back. The air is sucked down across it.
This is a bit scary since I use the same mounting bracket as the Etsy version. Are others that are experiencing this heat pump issue also using this for their front plate?
i'm experiencing the heat pump issue and i use the default plate install with double sided tape on the bumper. if you're worried you may have installed incorrectly, just turn on and off the climate using your phone while you watch the louvers move.
i have a model 3. i saw them move when i turned on my climate while using a heat gun to make sure it wasn't ice that was blocking the louver. i watched it move, but still didn't have heat, so its currently in for service and they found it was the compressor that failed.
Similar threads
