Signs Your EGR Cooler Might Be Failing (And Why It Matters)

A malfunctioning EGR cooler can significantly affect your vehicle’s performance, leading to reduced fuel efficiency, higher emissions, and even severe engine issues. In extreme cases, it might force your engine into a dreaded 5mph derate mode. Here are seven warning signs to help you catch the problem early:

1. Unexplained Coolant Loss or Internal Leaks

One of the most common indications of a failing EGR cooler is losing coolant without any visible leaks. Often, the issue is internal—a crack or damage within the cooler allows coolant to escape into the system.

When this happens, exhaust gases can mix with the coolant, leading to over-pressurization in the reservoir tank and possible coolant overflow. This internal leakage can be particularly problematic if not addressed promptly.

2. Engine Overheating

A compromised EGR cooler can disrupt proper cooling, causing the engine to overheat. Prolonged overheating poses a serious risk to your engine and may result in significant damage if left unchecked.

3. Drop in Fuel Efficiency

If your fuel costs have been creeping up, a faulty EGR cooler might be the culprit. When the cooler isn’t working as designed, your engine operates less efficiently, leading to reduced miles per gallon.

4. Excessive Exhaust Smoke

Notice a change in your exhaust emissions? A damaged EGR cooler can produce increased smoke, often white or blue in color, signaling trouble in the system.

5. Illuminated Check Engine Light

Modern engines are equipped with sensors that detect malfunctions in the EGR system. If your check engine light comes on, it could indicate a problem with the EGR cooler. Diagnostic codes like EGR low flow, EGR efficiency issues, or differential pressure errors are common warning signs.

6. Reduced Engine Performance

A failing EGR cooler can compromise your engine’s performance, resulting in a noticeable decline in power and responsiveness. This can make your vehicle feel sluggish, especially under load.

7. 5mph Derate Mode

In extreme cases, an EGR cooler clogged with soot or leaking coolant can block proper EGR flow. When this happens, the engine may struggle to complete a regeneration cycle, leading to higher soot levels and triggering the 5mph derate mode. Addressing the issue promptly is crucial to avoid this frustrating scenario.

What Should You Do Next?
If you experience any of these symptoms with your Volvo D13 engine, don’t delay in getting the EGR cooler inspected and repaired. Ignoring these issues can escalate into costly repairs or prolonged downtime.

However, if the issue is limited to soot buildup, you might be able to clean the EGR cooler yourself.