1886655C4
EGR Cooler · Navistar
EGR cooler: the heat exchanger in the exhaust gas recirculation circuit, part-number assignment and replacement checks
The EGR cooler lowers the temperature of the recirculated exhaust gas before it is admixed into the intake tract, increasing the mass of recirculated gas for a given recirculation rate, which lowers peak combustion temperature more effectively than uncooled recirculation. The cooler is built as a tube-bundle or plate heat exchanger through which the exhaust gas flows, while engine coolant carries away the heat in counterflow; a bypass channel with its own valve can route around the cooler during warm-up.
The part number is tied to the type of heat exchanger, the number and cross-section of the tubes or plates, the coolant volume, and the connection geometry to the exhaust manifold and intake tract of the engine family. Versions with a bypass channel differ in how the valve is integrated, and as emission stages tightened, the cooling capacity of many designs increased through larger heat exchanger surfaces. The assignment of part numbers on this page comes from official certification documentation issued by the US Environmental Protection Agency.
Soot deposits and condensate from sulphur and nitrogen oxide compounds clog the narrow channels and reduce cooling capacity, first shown by a rise in intake air temperature and then by increased nitrogen oxide levels. Repeated temperature cycling between cold coolant and hot exhaust gas favours cracking at weld seams or tube sheets, allowing coolant to enter the exhaust stream or exhaust gas to enter the cooling circuit; coolant loss with no visible leak is a typical sign of an internal crack.
Replacement is governed by the part number, since cooling capacity, connection dimensions and the bypass channel design can differ between coolers that look similar. Checks should cover the sealing faces of the coolant and exhaust connections, the condition of hose and pipe joints, and a pressure test of the coolant circuit. After replacement, the coolant circuit must be bled carefully. Pricing and availability are not covered here.
Fits these engines (3)
| Navistar A240 | Heavy-Duty-Straßenmotoren |
| Navistar A260 | Heavy-Duty-Straßenmotoren |
| Navistar A300 | Heavy-Duty-Straßenmotoren |
Excludes price and availability — those come from the supplier.