Patent ID: 8386153

Claim:
A method for operating an internal combustion engine comprising: at least two cylinders each having a respective combustion chamber; at least one gas inlet valve; an intake duct fluidically coupled with the each of the respective combustion chambers via a respective cylinder inlet channel based at least in part on a switching position of the at least one gas inlet valve; at least one gas outlet valve; an exhaust section fluidically coupled with the each of the respective combustion chambers based at least in part on a switching position of the at least one gas outlet valve; an exhaust-gas recirculation valve; and an exhaust-gas recirculation line configured to recirculate exhaust gas from the exhaust section to the respective inlet channels based at least in part on a switching position of the exhaust-gas recirculation valve, the method comprising: measuring a temperature at each respective inlet duct when the exhaust-gas recirculation valve is in a closed position; determining a measurement offset for each respective inlet based on the measured temperature at each respective inlet duct; determining mixed-air temperatures in at least two of the respective cylinder inlet channels when the exhaust-gas recirculation valve is in an open position; one of adding and subtracting the determined measurement offset from at least one of the determined mixed-air temperatures to normalize the determined mixed-air temperatures in at least two of the respective cylinder inlet channels based on the measurement offset; comparing the at least two normalized determined mixed-air temperatures; and detecting an uneven distribution of recirculated exhaust gas if a difference between the normalized mixed-air temperatures of the at least two of the respective cylinder inlet channels is greater than a predetermined threshold value.