2016 - 2017 Cadillac CTS-V: GM TechLink: Fuel Line Pulsation Sound

2016 - 2017 Cadillac CTS-V: Fuel Line Pulsation Sound

March 29, 2017

GM TechLink

A rattle or ticking sound may be heard coming from the back of the left valve cover on some 2014 - 2017 Corvette, Silverado, Sierra; 2015-2017 Tahoe, Suburban, Yukon, Escalade; 2016 - 2017 Cadillac CTS-V, and Camaro models equipped with the following engines: 6.2L (RPO LT4, LT1, L86); 5.3L (RPO L83); or 4.3L (RPO LV3) It may sound similar to a lifter ticking and may be louder inside the vehicle.

Listen to the fuel line connection at the left side of the engine. The fuel feed line between the high pressure fuel pump and chassis fuel line may be allowing high pressure pulsation back to the low side of the fuel system. If the sound is heard, the line will need to be replaced. On some trucks and SUVs, a vibration also may be observed in the fuel line at the fuel tank.

There are two different types of fuel lines that contain a check valve. The lines vary by model. Only one line should be used on Corvette, truck and SUV models. (Fig. 9) The line connects the chassis fuel line to the high pressure fuel pump. (Fig. 10)

FIG. 9

FIG. 10

– Thanks to David Rutkowski