Why is my Acura running hot?

Your Acura running hot usually means the cooling system isn’t removing heat effectively. Common causes include low coolant, a stuck thermostat, a failing water pump, a clogged radiator, or a faulty cooling fan. The fix can range from a simple coolant top-up to more involved component replacements.

What overheating looks like and why it matters

Overheating is a warning sign that something in the cooling loop is not doing its job. If not addressed promptly, it can cause head gasket failure, warped cylinder heads, and other costly damage. Pay attention to gauge warnings, steam, or a noticeable coolant smell, and heater performance. Here are common signs to watch for.

• Rising temperature gauge or a warning light on the dash


• Steam, a hissing sound, or smells of hot coolant


• Puddles under the car or visible coolant leaks


• Heater producing little or no warm air


• Reduced engine performance or a check-engine/warning light

If you notice any of these, stop driving as soon as safely possible and have the vehicle inspected. Do not open the radiator cap while the engine is hot; allow the engine to cool, then check coolant levels. A professional can diagnose the underlying cause with cooling-system pressure tests and inspections.

Common causes of overheating in Acura models

Several components can fail or degrade, leading to overheating. The following are typical culprits for many Acura models:

• Low coolant level due to leaks, consumption, or improper refill


• Thermostat stuck closed or slow to open, preventing coolant circulation


• Water pump failure or worn impeller, reducing coolant flow


• Radiator issues such as clogging, debris, or a damaged cap, restricting heat transfer or pressure


• Cooling fans that fail to engage (bad relay, blown fuse, faulty sensor, or wiring problems)


• Faulty radiator cap causing loss of pressure and boil-over


• Head gasket failure or other seals, which can allow coolant to leak into cylinders or oil and cause overheating


• Air pockets in the cooling system after service or improper bleeding, which can impede circulation

Diagnosing the exact cause often requires a pressure test, leak checks, a visual inspection of hoses and belts, and, in some cases, a cooling-system flush or part replacement. A professional shop can identify the root cause and prevent further damage.

Practical steps to diagnose and fix safely

Before attempting DIY fixes, understand safety considerations and know when to stop driving. The following steps provide a structured approach to identify and address overheating problems in an Acura.

• Check the coolant level when the engine is cold, and inspect hoses and the radiator for obvious leaks or damage


• Look for signs of coolant leakage under the vehicle and replace any leaking hoses, clamps, or radiator components as needed


• Verify whether the cooling fans engage when the engine is hot or when you turn on the AC; a non-working fan can indicate a bad relay, fuse, sensor, or wiring issue


• Inspect the radiator cap for wear or failure; a faulty cap can cause pressure loss and boil-over


• Bleed air from the cooling system if you recently did a coolant service; follow the bleeding procedure in the owner's manual or have a pro do it


• Check the water pump and drive belt for signs of wear, noise, or leakage, which can impair cooling


• If overheating persists, avoid driving a long distance and seek professional diagnosis to prevent head-gasket damage or other severe engine problems

After completing these checks or repairs, monitor the temperature gauge and look for steady cooling performance. If readings remain high or leaks continue, seek professional diagnosis promptly to avoid further damage.

Model-specific considerations for Acura

Acura vehicles share a family of engines and cooling-system designs, but there are model-specific nuances. For example, some MDX and TLX models with V6 engines use a particular bleed and refill procedure to remove air from the cooling system after service. Always refer to the owner's manual for the correct bleeding sequence, coolant type, and replacement intervals. Using the recommended coolant at the proper mix ratio is crucial for heat transfer and corrosion protection.

Additionally, certain Acura models have had recalls or service campaigns related to cooling-system components. Staying current with recalls and service bulletins via Acura’s official portal or your dealer can help catch emerging issues before they lead to overheating.

When to seek professional help

Overheating can quickly jeopardize the engine, so if you notice persistent high temperatures, steam, or coolant loss, contact a certified mechanic or Acura dealership promptly:

• Engine temperature remains high despite basic checks and topping off coolant


• Visible leaks, sweet coolant smell, or oil contamination in the coolant


• Warning lights on the dash or a check-engine light


• Unusual noises from the water pump, inoperable cooling fans, or a suspected faulty thermostat

Delaying repair can cause head-gasket failure, warped cylinder heads, or other severe damage that can be far more costly than a diagnostic visit.

Summary

Overheating in an Acura signals a cooling-system problem that deserves prompt attention. Common causes include low coolant, thermostat or water-pump failures, radiator or cap issues, and cooling-fan problems. Start with safety-first checks: verify coolant level and leaks, confirm fans operate, and inspect the radiator cap. If the issue persists, seek professional diagnosis to prevent serious engine damage. Understanding signs, causes, and safe steps helps Acura owners protect their vehicles and plan timely repairs.

Why is my car overheating but the coolant is full?

If your car's coolant is full but the engine is overheating, it could be a sign of a malfunctioning thermostat, a clogged radiator, a faulty water pump, or a problem with the cooling fans. Other causes include air pockets in the cooling system, a faulty radiator cap, or a serious issue like a head gasket leak. 
This video explains the basic principles of the cooling system and common reasons for overheating: 53sOne Trick TechnicianYouTube · May 5, 2025
Potential causes

• Thermostat: If the thermostat is stuck closed, it will block coolant from circulating to the radiator, trapping heat in the engine. 
• Clogged or damaged radiator: Debris can block the radiator, preventing it from dissipating heat. Internal clogging can also occur, even without external blockage. 
• Faulty water pump: The water pump is responsible for circulating coolant. If it's failing or the belt driving it is broken or slipping, the coolant won't flow properly. 
• Cooling fans: The electric fans are crucial for pulling air through the radiator, especially at low speeds or while idling. If they're not working, the coolant won't cool down. 
• Air pockets: Trapped air in the cooling system can block coolant flow and cause temperature spikes. This can happen after a leak or repair and may also lead to a non-working heater. 
• Bad radiator cap: The cap is designed to keep the system under pressure. If it's faulty, the coolant can boil at a lower temperature, hindering circulation. 
• Head gasket failure: A failing head gasket is a more serious problem that can allow hot exhaust gases to enter the cooling system, causing overheating. 
• Incorrect coolant: Using the wrong type or mix of coolant can affect the system's performance. 

What you can do

• Check the cooling fans: Turn on the air conditioning to see if the fans kick on. If they don't, there could be a blown fuse or a bad fan motor. 
• Inspect the radiator: Look for any visible external debris that might be blocking airflow. You may be able to rinse the fins with a garden hose. 
• Check for leaks: While you may not see an obvious leak, check hoses, the radiator, and the water pump for signs of leakage. 
• Bleed the system: If you suspect air pockets, you may need to bleed the air out of the cooling system. This can often be done with specialized tools or by running the engine with the radiator cap off and adding coolant as needed. 

You can watch this video to learn how to replace a thermostat: 47sScotty KilmerYouTube · Jul 6, 2010
Important: Ignoring an overheating engine can cause severe and permanent damage. If you're unsure about performing these checks, it is best to have a professional mechanic diagnose the problem.

Will a coolant flush fix overheating?

Yes, a coolant flush can fix overheating if it's caused by old or contaminated coolant, rust, or sludge blocking the system. By removing these blockages and replacing old fluid with fresh coolant, a flush allows the cooling system to work more efficiently and regulate engine temperature properly. However, if the overheating is due to another issue, like a faulty water pump, thermostat, or a leak, a coolant flush alone will not solve the problem, as explained in this YouTube video. 
You can watch this video to learn how to perform a super flush of your car's cooling system: 1mChrisFixYouTube · Mar 6, 2015
How a coolant flush helps with overheating

• Removes blockages: Over time, coolant can break down and form rust, scale, and sludge, which can clog passages in the radiator and engine. Flushing removes these blockages, allowing coolant to circulate freely. 
• Improves heat transfer: Fresh coolant has better heat transfer properties than old, degraded fluid. A flush ensures the system is full of effective fluid, which is crucial for preventing the engine from overheating. 
• Restores system efficiency: A clean system with fresh coolant runs more efficiently, which can also improve fuel economy. 

When a coolant flush is not enough

• Air in the system: A common post-flush issue is air pockets, which disrupt coolant flow and cause overheating. The system needs to be "bled" correctly to remove all air. 
• Other component failures: A flush won't fix a failing water pump, a bad thermostat, a damaged radiator, or a leak in the hoses or connections. These are separate mechanical problems that require diagnosis and repair. 
• External radiator damage: Physical damage to the radiator fins from debris can impede airflow. Cleaning the fins is necessary in addition to flushing the system, notes this YouTube video. 

This video demonstrates how to identify and fix an overheating issue after a coolant flush: 56sAuto Repair GuysYouTube · Apr 19, 2020
What to do

• Get a flush: If you haven't had a flush recently or if the signs of contamination are present, a flush is a good first step to try and fix the overheating. 
• Have the system bled: Make sure the mechanic properly bleeds the air out of the system after the flush. 
• Inspect other components: If the overheating continues, have a mechanic thoroughly inspect the water pump, thermostat, radiator, and hoses for any other potential problems. 

Why is my Acura overheating?

Your Acura is likely overheating due to a problem with the cooling system, most commonly a coolant leak, a faulty thermostat, or a malfunctioning radiator fan. Other possibilities include low oil levels, a clogged air filter, a bad water pump, or air pockets in the system. 
You can watch this video to learn about the causes of overheating, including radiator fans and the thermostat: 58sRB The MechanicYouTube · May 25, 2021
Common causes

• Coolant leaks: This is the most frequent cause, and leaks can come from hoses, the radiator, the water pump, the heater core, or the head gasket. 
• Faulty thermostat: A thermostat that fails to open properly will prevent coolant from circulating, leading to overheating. 
• Bad radiator fan: The fan pulls air through the radiator to cool the engine. If it fails, especially at low speeds, the engine will overheat. 
• Low coolant or oil: Both low coolant levels and low oil levels can cause overheating because the engine isn't getting the proper cooling or lubrication it needs. 
• Clogged components: Debris can block the radiator or coolant hoses, restricting flow and causing heat to build up. 
• Air pockets: Air in the cooling system can cause the engine to overheat. 
• Faulty radiator cap: A bad cap can cause pressure issues, leading to coolant loss. 

This video demonstrates how to inspect a radiator for blockages that cause overheating: 1mInnova ElectronicsYouTube · Feb 29, 2016
What to do

• Pull over immediately: If your temperature gauge is in the red, turn off the engine and pull over safely to prevent serious engine damage. 
• Turn on the heat: As a temporary measure, turn your heater on full blast to draw some of the engine's heat into the cabin. 
• Let it cool: Do not open the hood or attempt to work on a hot engine, as you could be badly burned by hot coolant or steam. 
• Check for obvious issues (after cooling): Once the engine has cooled down, you can check for leaks, look at the coolant reservoir level, and check the radiator fan. 
• Call for a tow: The safest and most recommended course of action is to have the vehicle towed to a mechanic for diagnosis and repair. 

What is the most common problem with Acura?

A common problem for Acura models includes transmission issues in older models and occasional electrical malfunctions.