The Tesla Heat Pump System: A Brief Introduction

The heat pump system in a modern Tesla vehicle is a marvel of automotive engineering. First introduced within the Model Y in 2020, the heat pump became standard equipment on the Model 3, Model S and Model X one year later in 2021. The term “heat pump” does not refer to a single component, but rather a complex system with dozens of parts. Not only does the heat pump system replace the energy-thirsty resistive PTC cabin heater used in older Teslas, but it handles temperature control all over the vehicle. Battery too cold? Drive unit too hot? The heat pump controls this, moving thermal energy from where it’s not needed to where it is. Here is a fantastic YouTube video explaining the whole thing, if you ever find yourself with an hour to kill.

Sadly, the early Tesla heat pumps haven’t proven as reliable as owners would expect, prone to compressor failures that pump metal shrapnel through the rest of the system — but that’s an article for another day. This article is about a more common, but much more easily rectified issue: a plugged radiator. This is a “when it happens, not if it happens” issue on the Model 3 and Model Y in particular, with the radiators in these vehicles being quite prone to debris build-up and restriction.

What Happens When My Tesla Radiator Is Dirty/Plugged?

A plugged or restricted radiator drastically reduces the heat pump system’s ability to shed waste heat. This not only affects your cabin air conditioning, but all of the other heat-generating components inside the vehicle, too. When their radiator is becoming restricted, our Tesla clients will most often complain that:

• Air conditioning cooling is poor, especially when the vehicle is stationary.
• Heater performance in the winter is poor.
• The vehicle cannot maintain the interior temperature in Dog Mode/Pet Mode.
• Supercharging speed is reduced: charging usually starts out at the expected rate but soon drops to a much slower rate.
• The radiator cooling fans are louder, running more than normal or staying on longer after shutting the vehicle off.
• The autopilot computer (car computer) is overheating and/or the touchscreen keeps shutting off, particularly in hot weather.

Why Are The Model 3/Model Y Radiators Prone To Restriction?

Why do Tesla radiators get so dirty and plug up like they do? It comes down to a combination of design decisions. The first is that the Model 3/Y radiator is not mounted vertically, as radiators in most vehicles are. Instead, the Tesla radiator lays down at around a 30 degree angle, closer to horizontal than it is vertical. The 90 degree mounting angle employed in most cars means that bugs, dirt and rocks usually fall off the radiator, while in a Tesla, much of this debris just sits on top. The second factor is that to achieve their futuristic styling with a very small grille opening, the Model 3/Y radiators use very efficient, tight ducting and shrouding which channels nearly 100% of the air from the front grille opening through the radiator. Essentially, any debris that blows in through the grille has no choice but to end up in the radiator. The ducting in most vehicles isn’t nearly as well sealed, leaving lots of opportunities for debris to escape. Combine all of that with the fact that a Tesla grille opening is only 6 inches off the pavement, and you have a perfect recipe for a plugged radiator.

How Do I Know If My Tesla Radiator Is Restricted?

If you are experiencing any of the symptoms listed above, the easiest way to answer this question is to come see us! Our industry-leading service centre, where we service 5-10 Teslas every single day, is located at 93 Gateway Drive in Airdrie, Alberta. For Tesla owners familiar with using their vehicle’s Service Mode, you can now check radiator health within the Cooling System screen. This comes with a couple warnings, however:

1. This is just a calculation based on sensor data, and like every indirect inference, it can be wrong. The radiator health algorithm has improved with recent software updates but we still see vehicles where the radiator health measurement is good, but the vehicle has issues due to poor heat transfer at the radiator.
2. There’s a reason that Tesla included the “For Professional Technicians Only” warning in Service Mode. You can legitimately damage your vehicle with some of the included tools and special functions if they are used incorrectly. In addition, because it is common for Tesla vehicles to set meaningless/false alerts and trouble codes, a visit to your Alerts screen might leave you questioning “issues” that aren’t actually a problem.

How Do I Fix A Dirty/Plugged Tesla Radiator?

If your radiator becomes restricted, you have two options: replace the radiator, or clean it. We usually lean toward cleaning the radiator — it costs the client less, and it doesn’t make sense to throw away a perfectly good radiator when it can be saved. If you choose the cleaning route, there are two ways to go about this:

1. In-vehicle cleaning: Cheaper and easier, but this will only remove a portion of the build-up and usually doesn’t work on completely plugged radiators. If attempting an in-vehicle cleaning, some owners find that foaming cleaners meant for air conditioning condenser coils can help to loosen debris. This option may not solve your issue, but serves as good maintenance between more thorough cleaning.
2. Radiator removal and complete cleaning: This is the only way to completely restore your radiator to like-new condition, and it’s the option that we normally employ in our shop. The radiator is removed from the vehicle, then the cooling fan and other plastic covers/shrouds are removed. Using various tools, chemicals and techniques, we clean every bit of debris from the radiator. Then the vehicle is re-assembled, new Tesla G48 coolant is installed, and the cooling system is purged before we perform some testing to confirm that the heat pump system is working properly again.

How Much Does Tesla Radiator Cleaning Cost?

When performed in our service centre, by one of Alberta’s most skilled and caring EV Technicians, the service takes 2-3 hours from start to finish, and costs less than $600 including new coolant and GST. As with everything else we do, our premium service includes the perks you’ve come to expect from My Garage: A smiling and passionate team looking after you, conveniences like complimentary electric courtesy cars, the fact that your vehicle is always returned to you cleaner than when it arrives, and unmatched service down the road in the event of an issue.

How Can I Prevent My Tesla Radiator From Becoming Plugged/Restricted?

While it’s impossible to prevent a plugged radiator forever, there are steps that you can take to prolong the time between cleanings. One of the most effective is to purchase an aftermarket clip-in grille screen, such as this one from Amazon. Different Tesla models use different screens, so read the fine print before ordering. These are easy to install — you won’t need our help with this repair — and they make a big difference.

It also helps to rinse out your radiator during car washes. This can be done directly through the grille opening and if the your grille shutters are closing, preventing cleaning, just turn on Pet Mode and they should open up for you. Just be careful with your direction of spray and avoid very high pressure; you don’t want to bend/fold over the radiator fins.

What About Older Teslas? Let’s Talk Condenser Cleaning

Older Tesla models like the Model 3 from 2017-2020 do not use a heat pump, but they suffer similar airflow restriction concerns. These vehicles use a traditional air conditioning condenser mounted in front of the coolant radiator — and it’s the condenser that gets plugged instead. Like a radiator-only heat pump system, the same principles apply: partial cleaning of the condenser is possible in the vehicle, but a thorough and complete cleaning will necessitate removing the condenser. This is a more expensive, longer process than with newer Teslas, partially because the air conditioning refrigerant must be recovered and recharged as part of this service.

This is a great time to replace your air conditioning desiccant bag if it hasn’t been changed recently, a maintenance item that Tesla recommends every six years. We do not charge for any additional Technician time if the desiccant is replaced during the condenser cleaning.

Any Questions?

If you have any questions about radiators, heat pumps or anything Tesla/EV-related at all, don’t hesitate to reach out! We are Alberta’s electric vehicle experts, and are always happy to chat. You can email us at service@mygarageairdrie.ca or call/text us during operating hours at 587-600-1346.