OIl pressure sending unit....Where is it?!?!?!?
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OIl pressure sending unit....Where is it?!?!?!?
I just picked up a 77 F150 with a big block (previous owner says 460, VIN says 400). Where is the oil pressure sending unit....I looked around the engine (esp. around the Oil Filter, which is where I have usually found it on other motors) but cannot locate it...
I am getting very erratic pressure reading, (but my other gauges are fine).
Also, can somebody tell me how I can figure out if this is a 400 or a 460? I know the heads have been replaced, but otherwise it has not been rebuilt.
Thanks,
ackusackus
(ford truck newbie)
I am getting very erratic pressure reading, (but my other gauges are fine).
Also, can somebody tell me how I can figure out if this is a 400 or a 460? I know the heads have been replaced, but otherwise it has not been rebuilt.
Thanks,
ackusackus
(ford truck newbie)
Post Fiend
Joined: Feb 2000
Posts: 5,130
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From: Brea CA
OIl pressure sending unit....Where is it?!?!?!?
Hi ackusackus and welcome to FTE! As far as the two engines, the 400 has the thermostat outlet on the front of the engine while the 460 has it on the front of the intake manifold. In either engine, the oil pressure sending unit is located on top of the engine block, behind the intake manifold (of course, huh).
Barry
Barry
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OIl pressure sending unit....Where is it?!?!?!?
[updated:LAST EDITED ON 14-Jan-02 AT 04:53 PM (EST)]okay, so I have a 460.....and as for the sending unit......oh $%^&!!! That was the 1 part of the engine I could not get a look at.....figures......well looks like it is gonna be a job for Mr. Bloody knuckles.....I don't have to pull the manifold to get to it do I?!?!?!?
thanks for the quick response!!
One other thing....where should a healthy sending unit and gauge place the needle? I live in the pacific NW (averages in the 30's to 40's during the day), and am running 5w30. right now when the engine is hot and the needle is behaving, it sits at the lower line /------\ (not on the "L"...but the line that shows the "low normal" reading). Is this typical for a big block? It does not burn any oil, does not leak...runs like a raped ape....but I am used it being on the high side of normal on my last ford (an 88 ranger)
thanks for the quick response!!
One other thing....where should a healthy sending unit and gauge place the needle? I live in the pacific NW (averages in the 30's to 40's during the day), and am running 5w30. right now when the engine is hot and the needle is behaving, it sits at the lower line /------\ (not on the "L"...but the line that shows the "low normal" reading). Is this typical for a big block? It does not burn any oil, does not leak...runs like a raped ape....but I am used it being on the high side of normal on my last ford (an 88 ranger)
Post Fiend
Joined: Feb 2000
Posts: 5,130
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From: Brea CA
OIl pressure sending unit....Where is it?!?!?!?
No problem, I try to answer quick questions when I leaf through the threads. The manifold stay's put.
Barry
Hey, no fair editing while I’m posting back.
My experience with stock motors is the lower part of the line while idling and about midrange while cruising.
Barry
Hey, no fair editing while I’m posting back.
My experience with stock motors is the lower part of the line while idling and about midrange while cruising. 
Lead Driver
Joined: Mar 2000
Posts: 9,359
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From: Hampstead, NC
OIl pressure sending unit....Where is it?!?!?!?
Like Barry said, you don't have to remove the intake. You will, however, have to get a short 9/16" wrench (a regular wrench is too long to clear the firewall) and lay across the top of the engine to replace the sender (been there, done that). The 460 in my F-150 runs at the top of the guage hot or cold. The needle usually sit on the "L" in normal.
New User
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OIl pressure sending unit....Where is it?!?!?!?
Things that affect engine oil pressure:
Viscosity of oil
Length of time/mileage oil has spent in the engine
Condition of engine bearings(mileage of engine)
Condition of oil pump
Things that affect the measuring of oil pressure on gauges:
Condition of gauge
Condition of IC Voltage regualtor
Condition of wire connections
Condition of sending unit
The way the sending unit has been installed(with or without Teflon tape *A NO-NO * (Special sealant is required to avoid problems)
Blockage of oil passages.
Dennis
Oh....Please Don't Ask Me Any Tough Questions As:
"I'm Saving Up MY Memory For When I Develop Alzheimer's"
78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles
Viscosity of oil
Length of time/mileage oil has spent in the engine
Condition of engine bearings(mileage of engine)
Condition of oil pump
Things that affect the measuring of oil pressure on gauges:
Condition of gauge
Condition of IC Voltage regualtor
Condition of wire connections
Condition of sending unit
The way the sending unit has been installed(with or without Teflon tape *A NO-NO * (Special sealant is required to avoid problems)
Blockage of oil passages.
Dennis
Oh....Please Don't Ask Me Any Tough Questions As:
"I'm Saving Up MY Memory For When I Develop Alzheimer's"
78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles
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OIl pressure sending unit....Where is it?!?!?!?
Okay, this has turned into a automotive repair equivilent of the movie Speed.....just when you think things can't get worse they do....
I found the sending unit right where it should be......I had to move some hoses out of the way to get at it.....so I decide "hey, I can get this sucker swapped out in no time"........famous last words....
I used the new one to figure out that I needed a 9/16 wrench (I tried to check this post yesterday before I started but the board was down for maintinence, so I missed ford79's post....so I try to get the 9/16 on there....obviously there is not room...but it felt like it was even too small to get on....so I go buy a short wrench *set* thinking it might be a different size, it turns out that the 9/16 is the one (though it is a little lose).....soo long story short.....the sucker ain't coming off....I even took a big pair of channel locks to the body of the sending unit......the body now spins free from the threaded mount......and now it leaks oil......where it did NOT before.......
now the funny thing......
the sending unit now works relaiblly and correctly......(but leaks)
**sigh**
any ideas?
I found the sending unit right where it should be......I had to move some hoses out of the way to get at it.....so I decide "hey, I can get this sucker swapped out in no time"........famous last words....
I used the new one to figure out that I needed a 9/16 wrench (I tried to check this post yesterday before I started but the board was down for maintinence, so I missed ford79's post....so I try to get the 9/16 on there....obviously there is not room...but it felt like it was even too small to get on....so I go buy a short wrench *set* thinking it might be a different size, it turns out that the 9/16 is the one (though it is a little lose).....soo long story short.....the sucker ain't coming off....I even took a big pair of channel locks to the body of the sending unit......the body now spins free from the threaded mount......and now it leaks oil......where it did NOT before.......
now the funny thing......
the sending unit now works relaiblly and correctly......(but leaks)
**sigh**
any ideas?
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Lead Driver
Joined: Mar 2000
Posts: 9,359
Likes: 1
From: Hampstead, NC
OIl pressure sending unit....Where is it?!?!?!?
Did you try to remove it with the engine warm? Thats how I had to do it. The sending unit wouldn't move with the cold engine. I had to lay across the engine to be able to get enough leverage to turn the thing. Also (this may sound stupid) make sure you are turning it the right way 
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OIl pressure sending unit....Where is it?!?!?!?
All,
Let me jump in on this. I've got a 78 F150. It's got an Idiot light. Can I convert my Factory I/P to an oil gauge? How?
Good Luck, Have Fun,
KingFisher
Let me jump in on this. I've got a 78 F150. It's got an Idiot light. Can I convert my Factory I/P to an oil gauge? How?
Good Luck, Have Fun,
KingFisher
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OIl pressure sending unit....Where is it?!?!?!?
lefty loosy righty tighty 
yes, I am turning it the right way...unless it has the threads backwards.....maybe I better check that... I am also trying it on a warm....well...HOT engine.....I got home (freeway drive so everything gets good and hot), pop the hood and got started within 10 minutes........
maybe some strategically placed C4......hmmmmmmmm
yes, I am turning it the right way...unless it has the threads backwards.....maybe I better check that... I am also trying it on a warm....well...HOT engine.....I got home (freeway drive so everything gets good and hot), pop the hood and got started within 10 minutes........maybe some strategically placed C4......hmmmmmmmm
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