Diagnosing a Cracked Exhaust Manifold with a Smoke Machine | Chrysler 200

Customer Complaint and Initial Suspicions

• 🎯 A customer reported an exhaust noise and odor that occurs only during cold starts and dissipates after about a minute.
• 💡 The initial suspicion is a leaking exhaust manifold gasket or a cracked manifold, as these symptoms are common for such issues.

Smoke Machine Diagnosis Procedure

• 🚗 The vehicle, a 2012 Chrysler 200, was left overnight to ensure the engine was stone cold for an effective diagnosis.
• 💨 A smoke machine was used by inserting it into the tailpipe to fill the exhaust system with smoke, allowing for visual identification of leaks before starting the engine.
• ⚠️ It's crucial for the engine to be completely cold for this method to work, as a warm catalytic converter can consume the smoke, rendering the test ineffective.

Identifying the Leak

• 🔍 After filling the system with smoke, black staining was observed around an air injection pipe, indicating a potential leak area.
• 🛠️ To get a clearer view, the heat shield over the manifold was removed, which proved difficult due to rusted bolts requiring heat to loosen.
• 💨 Smoke was seen escaping from the bottom of the exhaust manifold, suggesting the manifold itself might be cracked.

Confirming the Crack and Temporary Repair

• 🧼 A soapy water solution was applied to the suspected area, and bubbles confirmed a significant leak, indicating a crack in the manifold.
• 💡 The crack appeared to be a poor weld, possibly a factory defect, and extended further than initially visible.
• 🔥 A temporary repair was attempted by welding the crack, with the understanding that this is a short-term fix and a new manifold is recommended.

Post-Repair Assessment and Recommendations

• ✅ After the weld, the engine was started, and the exhaust noise was significantly quieter, though a small trace of smoke was still faintly visible.
• ⚠️ The customer will be quoted for a new manifold, and a waiver will be required for the temporary repair, emphasizing that the vehicle should not be driven due to the risk of breathing exhaust fumes.
• 🔧 The video highlights the effectiveness of smoke machines for diagnosing exhaust leaks, especially when the engine is cold, and the importance of proper diagnosis when symptoms are intermittent.