Why is the coolant disappearing in my Chevy Trax?

Coolant loss in a Chevy Trax is most often caused by a leak or a cooling-system fault, and it should be diagnosed promptly to prevent overheating.

In practice, you should inspect for external leaks, check the reservoir and hoses, test the system pressure, and consider whether an internal issue like a head gasket could be involved if you notice milky oil or white exhaust. The Trax uses Dex-Cool orange coolant and requires proper bleeding after service. If you notice overheating, unusual smells, or visible coolant stains, treat it as a sign to investigate further.

Common causes of coolant disappearance

Below are the most frequent sources of coolant loss on the Trax and how to spot them during inspection.

• External leaks from cooling system components (radiator, radiator hoses, clamps, water pump weep hole, radiator cap, or the overflow reservoir). Signs include puddles under the vehicle, damp spots on hoses, crusty deposits, or staining around the fittings.


• Heater-core or firewall leaks. A damp cabin carpet, a persistent sweet coolant odor inside the car, or fogging on the windshield when the heater is on can indicate a heater-core leak.


• Internal leaks such as a head gasket or intake-manifold gasket. Symptoms include milky or frothy engine oil, white/gray exhaust smoke, overheating, or rapid coolant disappearance without obvious external leaks.


• Cooling-system component failure, like a stuck thermostat or a failing water pump, which can reduce coolant circulation and cause overheating.


• Faulty radiator cap or pressure-regulating components. A bad cap allows coolant to boil off or escape at normal operating temperatures, leading to gradual loss.


• Using the wrong coolant or mixing types. The Trax typically requires Dex-Cool (orange) coolant and should not be mixed with other types or with plain water alone. Incorrect coolant can foam and cause leaks or corrosion.


• Damaged or cracked radiator or expansion tank. Visible cracks or a warped cap area can leak coolant unnoticed until you inspect closely or pressure-test the system.


• Small, hard-to-see leaks from clamps, hoses, or fittings. Leakage around hose ends or beneath clamps can be intermittent, especially after engine heat cycles.


• Air pockets or incomplete bleeding after service. If the system isn’t properly bled, coolant can become trapped and boil off or reduce cooling efficiency, causing apparent loss.

Conclusion: By visually inspecting and performing a pressure test, you can often pinpoint the source of coolant loss before it leads to overheating or engine damage.

How to diagnose coolant loss in a Chevy Trax

Use this step-by-step approach to identify whether the loss is external, internal, or due to a circulation problem.

1. Check the coolant level when the engine is cold and note the color. Look for any recent changes and compare with the previous level.


2. Inspect for external leaks around the radiator, hoses, water pump, thermostat housing, and the expansion tank. Look on the ground and under the vehicle for fresh coolant residue.


3. Examine the engine oil and the radiator for signs of contamination. Milky oil on the dipstick or dipstick tube, or creamy residue in the radiator, can indicate a head-gasket issue or internal leak.


4. Check for unusual exhaust smoke. White, sweet-smelling exhaust can indicate coolant entering the combustion chamber; a blueish tint can indicate burning oil.


5. Test the cooling-system pressure with a radiator-cap test or a dedicated pressure tester. If the pressure drops without visible leaks, there may be a hidden leak or a cap fault.


6. Inspect and, if needed, replace the radiator cap. A faulty cap can cause the system to vent coolant at normal temperatures.


7. Bleed the cooling system to remove air pockets. Follow the Trax service manual bleeding procedure to ensure proper coolant circulation and air removal.


8. Inspect the water pump and thermostat for proper operation. A failing pump or a thermostat stuck closed can restrict coolant flow and cause overheating.


9. Consider using a UV dye and a black-light viewer to locate small leaks. This can help identify leaks that are otherwise hard to see.


10. If the cause isn’t obvious, perform a chemical test for exhaust gases in the coolant or have a compression test performed. These tests help identify head-gasket failures or cracked cylinders or blocks.

Note: If the vehicle overheats or the coolant level drops quickly, pull over safely and avoid driving long distances. Persistent coolant loss should be diagnosed by a qualified technician, as head-gasket or cooling-system failures can cause serious engine damage.

Practical tips and safety reminders

Before you start diagnosing or topping coolant, keep safety in mind and use the correct coolant type and process to avoid further issues.

Before you start diagnosing or topping coolant, keep safety in mind and use the correct coolant type and process to avoid further issues.

• Use the recommended Dex-Cool coolant (orange) if your Trax calls for Dex-Cool, and never mix with green or blue anti-freeze unless the manufacturer specifies it as compatible.


• Do not open a hot cooling system. If the engine is hot, wait until it cools to avoid burns from steam and hot liquid.


• Keep a spare bottle of the correct coolant and a clean funnel in the vehicle for topping up when necessary.


• If you cannot locate a leak or you suspect an internal issue (head gasket, cracked head), seek professional service promptly.

Following these guidelines helps you manage coolant loss safely while you determine whether a simple leak or a more serious mechanical issue is to blame.

Summary

Coolant disappearance in a Chevy Trax is most commonly caused by external leaks, internal engine leaks, or cooling-system component failures. Start with a careful visual inspection, perform a pressure test, verify the correct Dex-Cool type and proper bleeding, and escalate to professional service if you notice overheating, milky oil, or abnormal exhaust. Prompt diagnosis protects the engine and preserves performance.

Why is my car losing coolant but no leak?

A car can lose coolant without an external leak due to internal leaks, such as a failing head gasket where coolant is burned or enters the oil, or a leaky heater core that releases steam inside the cabin. Other potential causes include a faulty radiator cap or a small, hard-to-see leak from a hose, thermostat housing, or water pump. To diagnose, check the oil for a milky appearance and the exhaust for white smoke, as these are signs of an internal leak. 
This video demonstrates how to check for milky oil, which can indicate a head gasket leak: 40sKurt of TradesYouTube · Mar 20, 2023
Possible causes 
This video explains common causes of coolant loss and how to troubleshoot: 1mMechanic BaseYouTube · Aug 30, 2025

• Blown head gasket: A failing head gasket can allow coolant to leak into the combustion chamber and be burned, or mix with the engine oil. 
• Leaking heater core: This internal radiator for your car's cabin can leak, releasing coolant as vapor into the passenger area, which may be noticed as a sweet smell or fogging windows. 
• Faulty radiator cap: A loose or damaged radiator cap can't hold pressure, allowing coolant to escape as vapor. 
• Small external leaks: Leaks from a hose, thermostat housing, or water pump might be too small or hard to see at first, especially if the coolant evaporates quickly or is flung away by a spinning pulley. 
• Cracked expansion tank or other components: A small crack in the plastic coolant reservoir or other parts can be hard to detect, especially since the leak may only occur when the system is under pressure and hot. 

How to diagnose 
This video shows how to test for a coolant leak using a pressure tester: 58sBudget MechanicYouTube · Oct 2, 2022

• Check the oil: Pull the dipstick and look for a milky or "milkshake" color, which indicates coolant mixing with oil. 
• Examine the exhaust: Look for excessive white smoke coming from the tailpipe, especially on a warm day. 
• Smell for a sweet odor: This could be a sign of a heater core leak into the cabin. 
• Use a coolant pressure tester: A mechanic can use a pressure tester to pressurize the cooling system and pinpoint the source of the leak. 

What to do

• Do not ignore the problem: Even a small leak can lead to overheating and serious engine damage. 
• Get it professionally checked: Because internal leaks can be hard to spot, it's best to have a mechanic use specialized tools to accurately diagnose the issue. 

Why is my Chevy Trax losing coolant?

A coolant leak in a 2017 Chevy Trax can stem from various problems such as deteriorating turbo cooler seals, radiator damage, cracked hoses, a defective radiator cap, or compromised thermostat housing. A failing water pump gasket might also be the culprit.

Why is my coolant mysteriously disappearing?

• Overfilling the cooling system
• A faulty radiator cap
• A worn-out radiator hose
• A leak that only occurs under certain operating conditions
• An undiagnosed cracked engine block or cylinder head, or a blown gasket
• Towing heavy loads

What is the most common problem with Chevy Trax?

In fact, 30% of the complaints on file with NHTSA involve the engine, powertrain, or fuel system. The complaints range from fuel injector failure to a fire in the engine compartment. Turbocharger problems are also among the common Chevrolet Trax problems.