Testing Additional Air Intake (Gulp Valve)
- Connect test lamp to gulp valve. Test must be made with vehicle on a dynamometer. Drive model 280 SE in 3rd or 4th gear and model 600 in 1st, 2nd, 3rd, and 4th gears. The test lamp should not light when depressing accelerator. Release accelerator to decelerate vehicle. Test light should light up at speeds above 15 MPH (280 SE) or engine speeds over 2900 RPM.
Courtesy of MERCEDES-BENZ USA
- To check mechanical functioning of valve, remove air line from air filter to valve at gulp valve. A suction should be noticed at speeds above 15 MPH (280 SE) when decelerating in 3rd or 4th gear. At engine speeds above 2900 RPM (model 600) suction should be felt at gulp valve when decelerating in any gear.