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Discussion Starter · #1 ·
I have a 96 caprice completey cloned into a impala ss . Ik it’s not a implala but deal was to good to pass up . My oil pressure drops real low when motor is at operating temp . Cold start it’s a1 . I replaced the oil pressure sensor nd same thing . Could the sending unit be my problem? Someone help , also can’t find location of the oil pressure sending unit not a mechanic lol just tryna learn as I go .
 

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The sender (sensor) is on the left back top of the engine. How many miles are on your engine? If the oil pressure warning does not sound, your pressure is still sufficient. If there are a lot of miles on the engine, the bearings may be getting a little worn. If so an upgraded oil pump or a little thicker oil can solve the issue. A higher flow pump will put more oil through the system, and can keep the pressure up. Using a higher pressure pump may not increase the pressure, because the volume will sill not put enough oil in the bearings to replace it as it is pushed out.
 

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Welcome to the Impala SS Forum. I recommend along with your steady searching this forum and others using the LT1 using appropriate keywords, along with more generalized browser searches. Don't pass up any opportunity to feed more details (a lot more details) to give anyone happening by as much as possible for them to make the most useful replies. To start:
How long you've had car.
When this started.
Any codes.
How are you defining 'low'?
Does the dash in yours have a dial, or, an idiot light?
 

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I have a 96 caprice completely cloned into a impala ss.
Is it a Caprice 9C1?
Is there a metal plate in back of the front seats to protect from getting backstabbed?
My oil pressure drops real low when motor is at operating temp. Cold start it’s a1.
I replaced the oil pressure sensor and same thing. Could the sending unit be my problem?
Someone help, also can’t find location of the oil pressure sending unit not a mechanic lol just tryna learn as I go.
If it is a 9C1, the upper left hand gauge is actually an oil pressure gauge; the needle's position roughly represents the oil pressure, from 0-80psi, despite the lack of numbers.
If it is a civilian Caprice, it is not actually an oil pressure gauge; the needle only has two positions:
pegged to the left - 5psi or less (might be wrong about that number, please feel free to correct)
3/4ths to the right - 6psi or more

... either way ...
 

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The second 9C1-LT1 I bought (1998), I went to where I bought my first 9C1-LT1.
(Best Police Cars in Williamsburg, south 2nd st between Wythe Ave & Kent Ave. (718)-387-8888.
Told them my fiancee and I wanted another 9C1-LT1.
The mechanic and I went for a test drive, where we both noticed something odd.
Throwing the car into turns or curves hard enough (lateral g's) pegged the oil pressure needle to the left briefly.

He bought that car at a deep employee discount, and replaced the oil pump assembly.
He then sold it to me privately for the same price that I was going to pay that dealership 5 weeks later.

Sorry about the length of the story.

Point is:
have a mechanic check it thoroughly.
10W40 instead of 5W30, is not as good a fix as replacing / upgrading the oil pump assembly.
 

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Discussion Starter · #7 ·
How many miles on it? Where are you located (city / state-province / country)? What kind of oil is in it? Is the car stock or modified?
The sender (sensor) is on the left back top of the engine. How many miles are on your engine? If the oil pressure warning does not sound, your pressure is still sufficient. If there are a lot of miles on the engine, the bearings may be getting a little worn. If so an upgraded oil pump or a little thicker oil can solve the issue. A higher flow pump will put more oil through the system, and can keep the pressure up. Using a higher pressure pump may not increase the pressure, because the volume will sill not put enough oil in the bearings to replace it as it is pushed out.
How many miles on it? Where are you located (city / state-province / country)? What kind of oil is in it? Is the car stock or modified?
Yea I figured that out after a little while , I just didn’t know the oil pressure sensor nd sending unit was the same thing . I don’t hear anything sounding indicating low oil pressure just the gauge on the dash drops pretty much to the red zone . It currently has 102k original miles, I’ll try the high pressure oil pump. I live in Stockton ca. by the way . Thanks for the help keep it coming please and thank you it’s highly appreciated
 

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Discussion Starter · #8 ·
The sender (sensor) is on the left back top of the engine. How many miles are on your engine? If the oil pressure warning does not sound, your pressure is still sufficient. If there are a lot of miles on the engine, the bearings may be getting a little worn. If so an upgraded oil pump or a little thicker oil can solve the issue. A higher flow pump will put more oil through the system, and can keep the pressure up. Using a higher pressure pump may not increase the pressure, because the volume will sill not put enough oil in the bearings to replace it as it is pushed out.
Yea I figured that out after a little while , I just didn’t know the oil pressure sensor nd sending unit was the same thing . I don’t hear anything sounding indicating low oil pressure just the gauge on the dash drops pretty much to the red zone . It currently has 102k original miles, I’ll try the high pressure oil pump. I live in Stockton ca. by the way . Thanks for the help keep it coming please and thank you it’s highly appreciated
 

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If I read this thread correctly, you say you are going to try a high pressure oil pump right after you were told not to.
As stated above a high pressure pump will do nothing to hot low rpm pressure.

May I suggest you get an accurate mech gauge temporarily hooked up and find out what your oil pressure actually is.

As also mentioned above, depending on the real numbers your engine may be a candidate for thicker weight oil.
 

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Using a higher pressure pump may NOT increase the pressure, because the volume will still not put enough oil in the bearings to replace it as it is pushed out.
I’ll try the high pressure oil pump.
... you say you are going to try a high pressure oil pump, right after you were told NOT to.
As stated above, a high pressure pump will do nothing to hot low RpM pressure.
A higher flow pump will put more oil through the system, and can keep the pressure up.
Beware of the person who cannot be bothered by details.
- William Feather
 

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Discussion Starter · #12 ·
If I read this thread correctly, you say you are going to try a high pressure oil pump right after you were told not to.
As stated above a high pressure pump will do nothing to hot low rpm pressure.

May I suggest you get an accurate mech gauge temporarily hooked up and find out what your oil pressure actually is.

As also mentioned above, depending on the real numbers your engine may be a candidate for thicker weight oil.
I must’ve read it wrong , but I am going to check it manually and see what it tells me . I’m currently using 10w30
 

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I had to replace the sending unit with 1 from a truck and removed the resistor from under the dash. My car had less than 50k miles and was doing exact same thing. Oil pressure fine with mechanical gauge. Mod worked great and I feel much better. Just search oil pressure gauge mod for a great write up with pictures for removing the resistor. FWIW worked for me.
 

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Forgive me if I missed this. Did you install an oil pressure sender (OE on a 9C1), or an oil pressure switch (OE on civilian Caprice/Impala)? Also, what did you remove, a switch or a sender? Did both items look the same when you made the swap? As mentioned above, installing a sender on a civilian Caprice/Impala requires removal of a grounded resistor located in the wiring in the dash, above the glovebox. Otherwise, your gauge will only display about 75% of your actual pressure. Also, the 9C1 sender reads 0-80 psi. A cold LT1 usually idles around 40. Using a 0-60 psi sender is a nice configuration for these cars. More here!
 
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Forgive me if I missed this. Did you install an oil pressure sender (OE on a 9C1), or an oil pressure switch (OE on civilian Caprice/Impala)? Also, what did you remove, a switch or a sender? Did both items look the same when you made the swap? As mentioned above, installing a sender on a civilian Caprice/Impala requires removal of a grounded resistor located in the wiring in the dash, above the glovebox. Otherwise, your gauge will only display about 75% of your actual pressure. Also, the 9C1 sender reads 0-80 psi. A cold LT1 usually idles around 40. Using a 0-60 psi sender is a nice configuration for these cars. More here!
I used GM pn 12553175 and 1/4 female to 1/8 male adapter and eliminated the resistor. Worked for me.
 
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