Methods and systems are provided for controlling engine oil dilution in automotive vehicles. The method comprises heating coolant by operating an exhaust gas heat recovery device and circulating the heated coolant via a first coolant loop between the exhaust gas heat recovery device and a heat exchanger; and heating coolant by operating an exhaust gas recirculation cooler and circulating the heated coolant via a second coolant loop between the exhaust gas recirculation cooler and the heat exchanger, wherein the heated coolant from both the exhaust gas heat recovery device and the exhaust gas recirculation cooler mix at the heat exchanger and allows heating of an engine oil via the heat exchanger. In one example, the method prevents excessive accumulation of water and/or fuel in the engine oil.

Methods and systems are provided for directing the flow of recirculated exhaust gas (EGR) delivered to an EGR cooler. In one example, a method includes flowing EGR through an EGR cooler positioned in an EGR passage, the EGR cooler comprising a bypass passage, a first cooler core flow path, and a second cooler core flow path, and adjusting a valve of the EGR cooler to selectively block flow of the EGR through the bypass passage, the first cooler core flow path, and the second cooler core flow path. In this way, fouling of the EGR cooler may be reduced.

Methods and systems are provided for directing the flow of recirculated exhaust gas (EGR) delivered to an EGR cooler. In one example, a method includes flowing EGR through an EGR cooler positioned in an EGR passage, the EGR cooler comprising a bypass passage, a first cooler core flow path, and a second cooler core flow path, and adjusting a valve of the EGR cooler to selectively block flow of the EGR through the bypass passage, the first cooler core flow path, and the second cooler core flow path. In this way, fouling of the EGR cooler may be reduced.

This engine includes an EGR device. The engine is provided with: an EGR gas temperature sensor; an EGR valve; an EGR control unit; an EGR valve position detection unit; a diagnosis unit; a first timer; a second timer; and a diagnosis control unit. The diagnosis unit diagnoses whether the EGR gas temperature sensor has failed, on the basis of a detected value from the EGR gas temperature sensor. The first timer, when the EGR valve is open, performs counting in accordance with the passage of time. The second timer, if a count value of the first timer is greater than or equal to a first threshold value set in advance, and if a predetermined condition is satisfied, performs counting in accordance with the passage of time. The diagnosis control unit prohibits diagnosis by the diagnosis unit if a count value of the second timer is less than a second threshold value set in advance, and permits the diagnosis if the count value is greater than or equal to the second threshold value.

This engine includes an EGR device. The engine is provided with: an EGR gas temperature sensor; an EGR valve; an EGR control unit; an EGR valve position detection unit; a diagnosis unit; a first timer; a second timer; and a diagnosis control unit. The diagnosis unit diagnoses whether the EGR gas temperature sensor has failed, on the basis of a detected value from the EGR gas temperature sensor. The first timer, when the EGR valve is open, performs counting in accordance with the passage of time. The second timer, if a count value of the first timer is greater than or equal to a first threshold value set in advance, and if a predetermined condition is satisfied, performs counting in accordance with the passage of time. The diagnosis control unit prohibits diagnosis by the diagnosis unit if a count value of the second timer is less than a second threshold value set in advance, and permits the diagnosis if the count value is greater than or equal to the second threshold value.

A method for controlling the temperature of re-circulated exhaust gas in an internal combustion engine includes operating the internal combustion engine on a base line mode, receiving a signal indicative of an engine operating temperature, wherein the engine operating temperature is one of coolant temperature, exhaust temperature and oil temperature, comparing the engine operating temperature to a predetermined IEGR threshold, when the engine operating temperature is less than the predetermined IEGR threshold, activating an IEGR mode and activating an EEVO mode, and when the engine operating temperature is greater than the first predetermined IEGR threshold, deactivating the IEGR mode and deactivating the EEVO mode.

A method for controlling the temperature of re-circulated exhaust gas in an internal combustion engine includes operating the internal combustion engine on a base line mode, receiving a signal indicative of an engine operating temperature, wherein the engine operating temperature is one of coolant temperature, exhaust temperature and oil temperature, comparing the engine operating temperature to a predetermined IEGR threshold, when the engine operating temperature is less than the predetermined IEGR threshold, activating an IEGR mode and activating an EEVO mode, and when the engine operating temperature is greater than the first predetermined IEGR threshold, deactivating the IEGR mode and deactivating the EEVO mode.

A cooling water flow control device of a cooling system for a vehicle can shorten a warm-up time of a cooling water being supplied to an exhaust gas recirculation (EGR) cooler. The cooling water flow control device includes: the EGR cooler that cools an exhaust gas supplied to an intake system of an engine using cooling water and includes an EGR cooler outlet through which the cooling water is discharged; a water pump to circulate the cooling water to the EGR cooler and the engine at an engine startup; and a direct flow path connected to a vent hole formed in the engine to guide the cooling water from the vent hole to a downstream side of an EGR cooler outlet.

A cooling water flow control device of a cooling system for a vehicle can shorten a warm-up time of a cooling water being supplied to an exhaust gas recirculation (EGR) cooler. The cooling water flow control device includes: the EGR cooler that cools an exhaust gas supplied to an intake system of an engine using cooling water and includes an EGR cooler outlet through which the cooling water is discharged; a water pump to circulate the cooling water to the EGR cooler and the engine at an engine startup; and a direct flow path connected to a vent hole formed in the engine to guide the cooling water from the vent hole to a downstream side of an EGR cooler outlet.

An exhaust gas recirculation (EGR) system utilizes an intake air pre-heater to selectively heat the cool, dry intake air prior to the mixing point with the hot, humid EGR gases. This intake air pre-heater utilizes available heat from a high pressure (HP) EGR heat exchanger, circulating a cooling/heating fluid between the HP EGR heat exchanger and the intake air pre-heater. The intake air pre-heater is disposed in an intake air filter box, optionally on the dirty side of the air filter, and includes a heat exchanger conduit that is contacted with the intake air. The selective operation of the intake air pre-heater is controlled via an electronic control module (ECM) of the vehicle, based on the operating conditions of the vehicle and an appropriate temperature control model. Flow of the cooling/heating fluid is selectively enabled/disabled by a pump and/or valve assembly disposed along the associated high temperature (HT) cooling/heating circuit.