What the heck is this

[93manual]

Doing an engine swap, my 93 k1500 hydro locked. I bought a 1989 k2500 with a 5.7 , the owner quit driving because the brake lines rusted out but eh engine only has 10K miles on it. I have the engine on a stand and it has an odd piece on the back I don’t know what it is, neither does the previous owner. Any ideas?

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[Supercharged111]

Oil pressure sensor.

 

[L31MaxExpress]

Oil pressure sender with the OE cover. The 87 G20 van had that non-sense to. It had the sender down low and a pressure switch at the top back of the block behind the intake. I moved both to the to the upper port behind the intake using the newer 3 wire sensor that is both the pressure switch for the fuel pump and the oil pressure sender. Cleaner setup, easier to access the sender to replace it and less stuff to leak. The van got a L31 350 so it already had the lower plug capped off with a pipe plug.

 

[454cid]

Why does it have a stove pipe from a coal stove around it???

 

[L31MaxExpress]

Why does it have a stove pipe from a coal stove around it???

Was a rigid piece of plastic on the 87 van. Best guess it is to try to help shield it. The one on the van looked identical. I know the 92 van I cut up for parts had the 3 wire single sender/switch. Not sure what year GM changed over, but apparantly some time between 1989 and 1992.

 

[garet]

Oil pressure sensor.

 

[GoToGuy]

Heat shield, vented to create airflow like a chimney stack.

 

[Schurkey]

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Correct "green stripe" oil pressure sending unit with heat-shield, and the NOT-correct (Too Damn Big) oil pressure sending unit called-for in some parts store catalogs. The number of the correct oil sending unit is BWD S4320. It has a silver case, and green paint around the end with the electrical connector.

CARQUEST - Part Information

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The NAPA / Echlin crossover from that number is OP6729. AutoZone sells it as PS150.

Note that this sending unit is not enormously reliable. I'm on my fourth one (I think...kinda lost count.) They can read too high, too low, or too variable. Sometimes they fill up internally with oil--they slosh when they're removed.

The heat shield is available as Standard # PS381.
www.oreillyauto.com/detail/c/standard-ignition/standard-ignition-oil-pressure-switch/std0/ps381/

https://www.oreillyauto.com/detail/c/standard-ignition/standard-ignition-oil-pressure-switch/std0/ps381/

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The OEM adapter is not quite 90 degrees. A home-made pipe thread 90-degree clusterfook will still not allow the too-big sending unit to clear both the block and the exhaust.

 

[someotherguy]

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Correct "green stripe" oil pressure sending unit with heat-shield, and the NOT-correct (Too Damn Big) oil pressure sending unit called-for in some parts store catalogs. The number of the correct oil sending unit is BWD S4320. It has a silver case, and green paint around the end with the electrical connector.

https://www.oreillyauto.com/search/1...up-4wd?q=S4320

You must be registered for see images

The NAPA / Echlin crossover from that number is OP6729. AutoZone sells it as PS150.

Note that this sending unit is not enormously reliable. I'm on my fourth one (I think...kinda lost count.) They can read too high, too low, or too variable. Sometimes they fill up internally with oil--they slosh when they're removed.

The heat shield is available as Standard # PS381.
www.oreillyauto.com/detail/c/standard-ignition/standard-ignition-oil-pressure-switch/std0/ps381/

https://www.oreillyauto.com/detail/c/standard-ignition/standard-ignition-oil-pressure-switch/std0/ps381/

Doesn't seem like it would take too much work to convert to the combo style sender/switch used on later models? A little re-routing of some wire. Or I wonder if the signal range is the same...? Not like those senders are super reliable or anything but they do seem to last quite a while before they become a problem.

Richard

 

[L31MaxExpress]

Doesn't seem like it would take too much work to convert to the combo style sender/switch used on later models? A little re-routing of some wire. Or I wonder if the signal range is the same...? Not like those senders are super reliable or anything but they do seem to last quite a while before they become a problem.

Richard

I have done the swap several times. Only need to match the sending unit to your gauge. Some have 60 psi and some are 80 psi. The resistance values are different.