Where is oil pressure sending unit on a 2005 6L silverado 2500HD?

Answer 1

Between the back of the engine and the firewall about 8 inches down, its a tight squeeze.

Access the sending unit from above, lay on the engine with a rug.

Un-clip the wire harness; its a clothespin style clip you squeeze the tab and pull up it comes right off.

You need a 1-1/16 deep socket to remove the faulty oil pressure sensor/(oil sending unit) and a small socket wrench with a 4" extension arm on the socket.

You can ratchet it off and back on with very small incremental turns because there is very little room to twist the wrench, but it will just fit using a deep socket and extension.

It takes under ten minutes to swap out.

A repair shop will tell you two hours time; this is time allowed for the oil to cool down.

If you had to you could replace it with a careful hand and the right tools while engine is medium hot.. maybe even get a small burn or two but there is tiny room to reach your tools down in there to avoid the heat.

The 1-1/16 deep socket costs around ten dollars and the sending unit was about $44.00.

Without a deep 1-1/16 socket it is impossible to change because there is no room to fit any type of wrench; not a small channel lock, crescent wrench, or even a sink/basin wrench.