Various embodiments of the teachings herein include methods for operating a motor vehicle having combustion chambers. The methods may include: closing the combustion chambers of the motor vehicle towards the exhaust tract by bringing outlet valves of the combustion chambers into the closed state; checking whether the outlet valves of the combustion chambers of the motor vehicle are in a closed state by evaluating the pressure prevailing in an intake pipe of the motor vehicle; and in the event one or more of the outlet valves are not in a closed state, initiating countermeasures to comply with emissions protocols.

A method for detecting valve leakage of a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the method comprising: acquiring a set of pressure data points indicative of the pressure in the cylinder intake manifold or exhaust manifold for crankshaft angular positions covering crankshaft angular rotation degrees such that each of the at least one valve has opened at least one time; and determining at least one test value based on the set of pressure data points, wherein a valve leakage is detected based on a comparison of the at least one test value to a threshold value.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body arranged coaxially with the drive-side rotary body and rotating integrally with a valve opening and closing camshaft; a fluid pressure chamber defined between the drive-side and driven-side rotary bodies; advance and retard chambers defined by partitioning the fluid pressure chamber; an intermediate lock mechanism selectively switches between a lock state and a lock release state; advance and retard flow paths allowing a flow of the working fluid to be supplied to and discharged from the advance and retard chambers; a control valve including a spool; and a phase control unit moving a position of the spool by controlling a power supply amount to the control valve to supply and discharge the working fluid to and from the advance and retard chambers to displace a relative rotation phase.

A method for adaptation of a detected camshaft position of a camshaft in an internal combustion engine with: Detection of an ACTUAL gas signal in a gas space that is associated with the camshaft and is associated with a detected camshaft position; Processing of the gas signal to produce an ACTUAL gas criterion; Modeling of multiple simulated gas criteria, each of which is associated with a target camshaft position; Determination of a simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of an ACTUAL camshaft position that corresponds to the simulated gas criterion with the least deviation from the ACTUAL gas criterion; Determination of a camshaft position correction value from the difference between the ACTUAL camshaft position determined and the detected camshaft position; Determination of corrected camshaft positions by correcting the detected camshaft positions with the camshaft position correction value.

Methods and systems are provided for adjusting engine cranking. In one example, a method for an engine cold start may include extending engine cranking at least based on one or more engine cold start conditions, where extending engine cranking may increase an engine oil pressure in a plurality of camshaft phaser cavities of a variable camshaft timing (VCT) phaser. In some examples, the method may further include, after engine cranking, enabling fueling. In this way, fuel efficiency considerations may be balanced with increases to the engine oil pressure such that components of the VCT phaser may be actuated and/or lubricated.

A system and associated methods for controlling valve motion in internal combustion engines provide a pulsing component for energizing a solenoid control valve in pulsatile fashion to cause a transient pressure change in a hydraulic network linking the control valve to a common, paired set of intake and exhaust main event deactivation mechanisms, which may be provided in respective valve bridges. The pressure change results in hydraulic deactivation of main event motion of the exhaust valve while avoiding deactivation of main intake event motion and thereby preserving intake main event valve motion, and supporting use of the intake main event motion for additional braking or other operations. The systems and methods are particularly suited for engine environments that employ cylinder deactivation (CDA) combined with high-power density (HPD) engine braking.

A variable valve lift (VVL) system for an internal combustion engine is provided that utilizes hydraulic fluid supply pressure feedback to provide noise free operation. The VVL system includes a high pressure pump, a solenoid valve, a pressure translating device, a one-way valve, and a hydraulic fluid pressure sensor. The high pressure pump is fluidly connected to the solenoid valve and pressure translating device by at least one fluid gallery that forms a high pressure chamber. The solenoid valve selectively fluidly connects the high pressure chamber to a middle pressure chamber formed by at least one fluid gallery that fluidly connects the one-way valve to the solenoid valve. The hydraulic fluid pressure sensor is arranged to detect a hydraulic fluid supply pressure of the one-way valve and provides feedback to an electronic controller that determines a proper fluid intake opening timing of the solenoid valve.

A method for detecting valve leakage of a least one valve at a cylinder intake manifold or exhaust manifold of a vehicle engine, the method comprising: acquiring a set of pressure data points indicative of the pressure in the cylinder intake manifold or exhaust manifold for crankshaft angular positions covering crankshaft angular rotation degrees such that each of the at least one valve has opened at least one time; and determining at least one test value based on the set of pressure data points, wherein a valve leakage is detected based on a comparison of the at least one test value to a threshold value.

A fully variable valve train with a rotary plunger for an internal combustion engine. A motor actuates a high-pressure oil injection pump; when a timing driven electromagnetic valve connected to an oil inlet is opened, high-pressure oil enters a hydraulic cylinder; and when the force applied to a plunger by the hydraulic oil is larger than the force of a valve returning spring, the plunger is pushed to move down, so that a valve is opened. When the valve is required to be return, the timing driven electromagnetic valve connected to the oil inlet is closed, and the timing driven electromagnetic valve connected to the oil inlet is opened; the valve moves up under the action of the valve spring, pushing the plunger to move up and thereby discharging the low-pressure oil out of the hydraulic cylinder, then the plunger and the valve return to the initial positions.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body arranged coaxially with the drive-side rotary body and rotating integrally with a valve opening and closing camshaft; a fluid pressure chamber defined between the drive-side and driven-side rotary bodies; advance and retard chambers defined by partitioning the fluid pressure chamber; an intermediate lock mechanism selectively switches between a lock state and a lock release state; advance and retard flow paths allowing a flow of the working fluid to be supplied to and discharged from the advance and retard chambers; a control valve including a spool; and a phase control unit moving a position of the spool by controlling a power supply amount to the control valve to supply and discharge the working fluid to and from the advance and retard chambers to displace a relative rotation phase.