Head Gasket Failure Confirmed on 2013 Dodge Durango – Overheating Diagnostic Story from PROFIX in Norman
A 2013 Dodge Durango SXT came to PROFIX Auto Repair in Norman overheating after long drives with hills. See how our technicians used a chemical block test to confirm head gasket failure and what we recommended next.
When a Dodge Durango starts overheating — especially after long drives through hills — and the customer notices the heater coming on while the vehicle is moving, it’s a strong clue that something serious is happening inside the engine. At PROFIX Auto Repair in Norman, we don’t guess. We test.
Customer Concerns
A customer brought in their 2013 Dodge Durango SXT with several issues:
- Loss of fluid / overheating, particularly while driving from south Texas and on hills (it improved somewhat after adding radiator fluid)
- Feeling like the transmission gets “stuck” or “gritty”
They also pointed out pink sludge under the radiator cap — a classic warning sign.
Step-by-Step Diagnosis
We began with a full cooling system pressure test. The system held pressure with no external leaks found. A test drive confirmed the vehicle was overheating, and the heater would turn on while the vehicle was in motion — another common indicator of combustion gases entering the cooling system.
Because head gasket failure was suspected, we performed a chemical block test. Here’s exactly how the test works and what we found:
The chemical block tester detects combustion gases in the cooling system. If the fluid changes to yellow or green, it confirms a head gasket leak or failure. In this case, the fluid turned green/greenish-yellow within minutes — a clear positive result. Combined with the pink sludge under the radiator cap, the diagnosis was definitive: head gasket failure.
Recommended Repair
Head gasket failure on this 3.6L V6 engine requires engine replacement which comes with a solid warranty: 2yr / 24k mile coverage, whichever comes first.
The job includes:
- Remove & Replace RWD Long Block Engine
- New gaskets (intake & exhaust manifolds, etc.)
- Spark plugs, coolant, oil & filter
- Coolant system air purge
- Full inspection and reassembly
This is a major repair, but it restores reliability and gets the vehicle back on the road with a warranted engine instead of repeated overheating issues or a potential stranding.
Key Takeaways
- Pink sludge under the radiator cap is almost always a sign of head gasket failure (coolant mixing with oil or exhaust gases).
- A chemical block test is a quick, reliable way to confirm combustion gases in the cooling system — far better than guessing.
- Overheating that worsens on hills or causes the heater to blow hot air while driving is a classic head gasket symptom.
- On higher-mileage vehicles like this 2013 Durango, a quality used long block with warranty is often the most practical and cost-effective solution.
If your Dodge Durango (or any vehicle) is overheating, losing coolant, showing pink sludge under the cap, or blowing hot air from the heater while driving, don’t wait. These issues never get better on their own and can lead to much more expensive damage.
Bring it to PROFIX Auto Repair in Norman for honest diagnostics and clear recommendations.
PROFIX Auto Repair – West
1121 Rambling Oaks Dr
Norman, OK 73072
📞 (405) 310-2279
🕒 Monday–Friday: 7:30 AM – 5:00 PM
Leon’s PROFIX Auto Repair – East
521 N Porter Ave
Norman, OK 73071
📞 (405) 364-2799
🕒 Monday–Friday: 7:30 AM – 5:00 PM
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