You need to consult a repair manual specific to your 2005 Ford Ranger 4.0L V6. The manual will provide the correct specifications for compression in PSI for that engine. These manuals often state a minimum acceptable compression, a typical range, and a maximum acceptable value. The numbers will be given for each cylinder individually, and you should expect some minor variation between cylinders.
Trying to find the information online without a specific manual is unreliable. Different sources may give conflicting information.
Without the correct specification from your vehicle's manual, any number I provide would be a guess and potentially misleading. Using an incorrect compression value could lead to misdiagnosis and unnecessary repairs.
To get the correct information:
1. Find a repair manual: Chilton, Haynes, and other publishers create repair manuals specific to vehicle makes, models, and years. These are widely available online and at auto parts stores.
2. Check the owner's manual: While less likely to contain precise compression specifications, it might offer some guidance or a reference to where to find the information.
3. Consult a mechanic: A qualified mechanic will have access to the correct information and the tools to perform a proper compression test.
In short: Don't rely on internet searches for this critical information. Use a proper repair manual or professional help.
