miked123

How do I replace the oil pressure sensor on a 1974 corvette 350 small block? (videos and pictures would be appreciated)

MelWff

You disconnect the sender wire and using an open end wrench unscrew the sender

speedreed8

with the engine not running of course....

blue by you

it is located by the dizzy

0Willcox Corvette

The oil pressure sending unit is located as shown below unless someone moved it to the top hole where plug number 2 is shown.

As stated, you just turn it with a wrench.

What is the gauge doing that has caused you to replace the sending unit? A oil pressure gauge is a twin to a fuel gauge so the gauge will tell you what is wrong with it.... So look at the chart below and see what your gauge is doing. If it reads like the top left picture then you are missing ohms input, so pull off the sending unit wire and ground it out... the gauge should go to 0 with the sender wire grounded. If it does this then the dash unit is working fine and you should replace the sender. If you purchase an aftermarket sender make sure you get one for a gauge and not for a car with dummy lights... Flaps like to sell the wrong sender to customers but they don't know that it'll cause a problem.

miked123

[QUOTE=Willcox Corvette;1594799003]The oil pressure sending unit is located as shown below unless someone moved it to the top hole where plug number 2 is shown.

As stated, you just turn it with a wrench.

What is the gauge doing that has caused you to replace the sending unit? A oil pressure gauge is a twin to a fuel gauge so the gauge will tell you what is wrong with it.... So look at the chart below and see what your gauge is doing. If it reads like the top left picture then you are missing ohms input, so pull off the sending unit wire and ground it out... the gauge should go to 0 with the sender wire grounded. If it does this then the dash unit is working fine and you should replace the sender. If you purchase an aftermarket sender make sure you get one for a gauge and not for a car with dummy lights... Flaps like to sell the wrong sender to customers but they don't know that it'll cause a problem.

My oil pressure gauge needle jumps around for about a second then stops completely, the oil pressure gauge is brand new so i think the oil pressure sender is bad.

0Willcox Corvette

[QUOTE=miked123;1594801753]Do the test stated above to see if the gauge is working properly... if it is replace the sender. If it fails then the dash unit or a shorted wire is the problem. You'll just have to do the test.

Willcox

miked123

where would the sender and the wire be at on the engine?

sparky77

Just above the oil filter .One other way to find out if it's the wire or the sender is pull the wire off the sender and have someone in the car looking at the gauge,key on, than ground the wire that you removed from the sender the gauge should move. If it does not than it could be a bad gauge or a bad wire if it does move than it will be the sender.

0Willcox Corvette

Unless someone moved it to the upper port, the factory sender is located where the picture I posted shows.

Willcox

miked123

I did the test and the gauge is fine. Im going to buy an oil pressure sender from Wilcox corvette. hopeful this works.

miked123

I also have one more question, my engine is missing the PCV valve, if it is missing, will that affect the reading on the pressure gauge?

0Willcox Corvette

The PCV missing will not affect the oil pressure gauge... but how is your engine breathing?????