Diagnostic Aids
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
- A faulty component may cause the following noises: One-way Check Valve - Buzz /Knock /Rattle /Tick @ 600 to 800 RPM
- An erratic low side fuel pressure leak-down reading may be caused by air/vapor in the fuel feed line, which can be caused by the following:
- Ambient conditions
- Engine operating conditions - Cold Start-Up/Warm/Hot
- Fuel Alcohol Content
- Fuel blend - Summer /Winter
- Fuel octane rating