7 Symptoms of a Failing EGR Cooler on your Detroit DD15 Engine

1. Coolant loss and internal coolant leak One of the most common symptoms of a failing EGR cooler is coolant loss. This can be caused by a leak in the EGR cooler itself or in the hoses that connect it to the engine. In many cases, the coolant loss is internal, which means that you may not see any visible signs of coolant leakage. An internal coolant leak can be caused by a crack in the EGR cooler itself. If there is a crack in the EGR cooler, it can also cause exhaust gases to mix with the coolant, causing the coolant reservoir tank to pressurize. This can lead to the coolant spilling out of the overflow. 2. Overheating If the EGR cooler is not functioning properly, it can cause the engine to run hot. This can lead to overheating and potential engine damage. 3. Decreased fuel economy A faulty EGR cooler can cause the engine to run less efficiently, resulting in decreased fuel economy. 4. Increased exhaust smoke A failing EGR cooler can cause an increase in exhaust smoke, particularly white or blue smoke. Check engine light The engine's computer may detect a problem with the EGR cooler and trigger the check engine light. Diagnostic trouble codes (DTCs) related to the EGR system, such as EGR low flow, EGR efficiency, and EGR differential pressure, may be stored in the engine's computer. 5. Decreased performance If the EGR cooler is not functioning properly, it can lead to decreased engine performance and power. 6. 5mph derate If the EGR cooler becomes plugged with coolant or soot (from age or possibly premature failure), the EGR flow may become so low that the truck cannot complete a regeneration. This can raise the soot level and cause the truck to go into a 5mph derate. It is important to address a failing EGR cooler as soon as possible to avoid this issue.