Cruze Diesel Sounds after Turning Vehicle Off

Some 2017 Cruze models equipped with the 1.6L turbo diesel engine (RPO LH7) may produce a squeak, chirp or whine sound shortly after the vehcle is turned off. There are several components that may be responsible for these sounds.


Intake Manifold Runner Control Valve Actuator


The intake manifold runner control valve actuator (Fig. 18, #1) performs an integrity check to confirm that the mechanical link between the actuator and the intake manifold runner is still connected. This check may be heard cycling under the hood after the engine is turned off.


Fig. 18


Diesel Exhaust Fluid Pump


The Diesel Exhaust Fluid (DEF) pump and the DEF reverting valve may be heard from the right rear of the vehicle. The DEF pump and reverting valve relieve the DEF system pressure and clear the lines of DEF when the vehicle is turned off. The reverting valve opens to relieve the pressure and sends the fluid back to the DEF tank. It closes once the DEF lines are clear.


These sounds are normal operating characteristics and do not impact the performance of the vehicle.


Examples of these sounds can be heard in the March 2017 Emerging Issues seminar, 10217.03, in the U.S. and the April 2017 TAC Talk seminar in Canada.


– Thanks to Richard Vandesteene

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