Locate the 4.3L Vortec oil pressure sending unit using this guide:
Primary Location (Most Common)
Find the sensor on the engine block, towards the rear on the passenger side:
- Behind the distributor.
- Above the rear of the oil filter pad/boss.
- Often near the cylinder head mating surface.
- It's threaded directly into an oil gallery port.
Alternative Locations (Less Common)
- Some models (e.g., certain GMT400 trucks like early Chevy C1500/GMC Sierra, Astro/Safari vans) mount it on the rear driver's side of the intake manifold, close to where it meets the cylinder head, above the valley cover and electrical connection center.
- On some applications, it might be found directly above the oil filter on a pad/boss on the block, passenger side, behind the alternator bracket.
Identifying Features
- Typically has a single electrical connector (1-wire sender).
- Threads directly into the block or intake (3/8" NPT thread common).
- Often coated in oil and grime.
Distinguishing from the Oil Pressure Switch (If Applicable)
Some models use a switch (lights dash light) instead of a sender. It looks similar but has a different electrical function.
- Do not confuse it with the fuel pump prime connector located nearby.
Key Notes
- Passenger side, near the distributor/firewall, is the most frequent location.
- Follow the oil filter boss up towards the rear of the block.
- Torque specifications for installation are typically very low (around 10 lb-ft or 18 Nm).