Tools You'll Need:
* Wrench: The correct size for your sending unit. This is usually a 7/16" or 1/2" wrench, but you should double-check your specific vehicle.
* Socket wrench and socket: A socket might be easier to use than a wrench, especially if the sending unit is tight.
* Drain pan: To catch any spilled oil.
* Rags or shop towels: To clean up any spills.
* New oil pressure sending unit: Make sure you get the correct replacement part for your Blazer.
* Penetrating oil (optional): If the sending unit is stubborn.
* Gloves: To protect your hands.
Procedure:
1. Warm up the engine: Run the engine for a few minutes to warm the oil, making it less viscous and easier to drain. *Important*: Don't run it for too long! You only need it warm enough to thin the oil.
2. Locate the sending unit: The oil pressure sending unit is typically located on the engine block, near the oil filter. It's a small, cylindrical unit with a single wire connected to it. Consult your owner's manual or a repair manual with diagrams if you have trouble locating it.
3. Prepare for removal: Place the drain pan under the sending unit to catch any oil that might spill.
4. Remove the sending unit: Use your wrench or socket to carefully loosen and remove the sending unit. It will likely be threaded. If it's stuck, apply penetrating oil and let it sit for a few minutes before trying again. Be gentle to avoid stripping the threads. Oil may leak out when you remove the unit.
5. Clean the area: Use rags to clean any oil or debris from the engine block threads where the sending unit was located.
6. Install the new sending unit: Screw the new oil pressure sending unit into the engine block by hand, carefully threading it in until it's snug. Then, tighten it with the wrench or socket to the manufacturer's specified torque. Don't overtighten!
7. Reconnect the wire: Reconnect the wire from the gauge to the new sending unit.
8. Check for leaks: Start the engine and check for any leaks around the new sending unit. Let the engine run for a few minutes to allow the oil pressure to build and verify the gauge is functioning correctly.
9. Check oil level: After running the engine, check your oil level and add more oil if necessary.
Important Considerations:
* Torque specification: Consult your repair manual for the correct torque specification for tightening the new sending unit. Overtightening can damage the threads.
* Oil type: Use the correct type and weight of oil for your engine, as specified in your owner's manual.
* Safety: Always work in a well-ventilated area. Be mindful of hot engine components.
If you're uncomfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic. Improper installation can lead to oil leaks and engine damage.
