Check the coolant level by inspecting the translucent expansion tank in the engine bay when the engine is cold. The level should sit between the MIN and MAX marks. If it’s low, top up with a 50/50 premixed Honda coolant until it reaches the MAX line, and never open the radiator cap when the engine is hot. If you notice persistent loss of coolant or leaks, have the system inspected.
Where to locate the coolant reservoir
The expansion (overflow) reservoir is a clear plastic tank in the engine bay, typically on the passenger side near the firewall. It carries MIN and MAX indicators to show the safe coolant range. The radiator cap is separate and should not be opened when the engine is hot.
To ensure you’re following the correct procedure, use the following steps as a practical guide:
- Park on a level surface and turn off the engine. Allow the engine to cool completely before touching the reservoir cap.
- Open the hood and locate the expansion tank; remove the cap only if the engine is cold.
- Check the coolant level against the MIN and MAX marks on the side of the tank. It should be between these two indicators and visible through the translucent plastic.
- If the level is below MIN, prepare to top up with the correct coolant Mix.
- Replace the cap securely after topping up, then run the engine with the heater set to hot to circulate the coolant. Watch for leaks as the system reaches operating temperature.
Following these steps helps ensure the cooling system remains properly filled and pressure-balanced.
What to use to top up
Using the right coolant and mixture is essential for protecting the engine from overheating and corrosion. The 2017 Honda Accord requires Honda-approved coolant and proper mixing ratios.
- 50/50 premixed Honda Type 2 coolant (blue, Honda Long Life Coolant) for most convenience and reliability.
- If you have concentrate coolant, mix it 1 part concentrate to 1 part distilled water to achieve the 50/50 dilution.
- Always use distilled water if you need to dilute coolant; avoid tap water to prevent mineral deposits and scale.
Using the correct coolant type and dilution helps maintain optimal operating temperatures and prevents corrosion inside the cooling system.
Safety and maintenance tips
Do not open the radiator cap while the engine is hot, and never attempt to remove the cap on pressurized parts. If you notice bubbling, white milky residue, or persistent low levels after a top-up, seek professional service to check for leaks or a blown head gasket.
When to seek professional service
If the coolant level drops repeatedly after topping up, if you see puddles under the vehicle, or if the temperature gauge regularly climbs toward the red zone, arrange a diagnostic with a qualified mechanic. A trained technician can pressure-test the cooling system, replace faulty hoses, caps, or the radiator, and perform a proper flush if needed.
Summary
To check coolant level on a 2017 Honda Accord, inspect the expansion reservoir when the engine is cold and ensure the level sits between the MIN and MAX marks. Top up with a 50/50 premixed Honda Type 2 coolant (or 1:1 coolant to distilled water if using concentrate) and never open the radiator cap when hot. Regularly monitoring the level and using the correct coolant helps prevent overheating and extends the life of the cooling system. If you notice recurrent low levels or leaks, consult a professional.