engine oil leak - help

[aknight_sa]

hi guys,

my truck was shipped across the country last week and after receiving it, i noticed a bad engine oil leak. its from the front left side (driver side) of the engine behind the power steering box.

the engine is a 454 big block from a 1986 truck.

attached are pictures of the part which is oil is spilling out from. the top of this is like an open valve (i think there should be some hose there).

 

[83ZZ502_Jimmy]

That is the engine oil pressure sender. Replace that part and hook the wire back up.

John

 

[aknight_sa]

where should it be connected too??

any diagrams? or part numbers so i can order it.

 

[dyeager535]

That looks like it's got two seperate pieces (common on all carbed/early TBI trucks)...the big bell shaped thing in the first pic is your oil pressure sending unit, which works with your stock oil pressure gauge, and it APPEARS that you've also got an oil pressure switch (second pic), which controls when the carb choke gets power.

You've got another option here, which simplifies things quite a bit IMO, but may not be practical in your case. The later trucks (about 1991) and cars such as Camaro's, did away with the two part setup, and went with a three wire combination switch/sender. It may or may not thread into the block in the location you presently have yours in, but can be adapted with the right fitting if necessary. The good thing (besides being one piece) is that if it WILL thread into the block, it takes no additional pieces, which can be a source for leaks.

If you've got pretty easy access to that sort of stuff, it may be an option. You'd need the correct 3 wire pigtail to splice your present two connectors/three wires into.

 

[4X4HIGH]

It appears that the oil pressure sender is bent enough that it's causing your leak. It's hard to tell from the pic but i can't see any wire hooked to it so maybe the end for the wire is broke as well.

 

[aknight_sa]

thanks for the info guys,

after getting a new one, where should the hose connect?

 

[4X4HIGH]

thanks for the info guys,

after getting a new one, where should the hose connect?

There is no hose, it's an electrical oil pressure switch.

Do you have an oil pressure gauge in the vehicle that is currently working? The reason i ask is because both of the switches you've pictured are electric switches and neither of them have any wiring connected to them. If you do have an oil pressure gauge that is working then it is hooked up elsewhere on the engine.

 

[aknight_sa]

actually the gauge hasnt been working sense i swapped the old engine with this one about 2 years ago.

 

[4X4HIGH]

Is this engine in the 81 Jimmy that you have listed in your profile? If so the original electric oil pressure switch on the SBC was located on the rear of the engine next to the distributor so you need to start looking back there for a lose wire or plug. Once you find this you need to extend the wire to reach the electric pressure switch on the driver front side of your 454 and connect it there once you've replaced the pressure switch. If you've found the correct wire and get it connected your gauge should work again. Just make sure that you buy a pressure switch for a Gauge if your jimmy has Gauges, or for an idiot light if it only has idiot lights. The senders are different between a gauge and a light.

 

[aknight_sa]

yes.. it is fitted on my 81 Jimmy... will be looking for the connector, and it has a gauge..

one more thing.. if you look at the second picture you will see the top of the connector which has the pressure sender connected too, why is that part open/? its where the oil is spilling out from... should there be something there?

 

[4X4HIGH]

yes.. it is fitted on my 81 Jimmy... will be looking for the connector, and it has a gauge..

one more thing.. if you look at the second picture you will see the top of the connector which has the pressure sender connected too, why is that part open/? its where the oil is spilling out from... should there be something there?

That is the pressure switch that Dorian was saying is for the choke. If that's leaking oil it's because the sender is broken somewhere on the body of it where the oil is located to make the switch work. The top side that you can see should have had a electric plug on it. Keep in mind that since this engine is a transplanted engine you don't need that switch if you're not having any trouble with the choke. You should be able to remove that switch from the brass fitting and put a NPT plug in instead to eleminate that leak without having to buy a switch that won't be used anyway.