No Oil Pressure?????

'88Cobra

Member

Oct 21, 2004

46

0

6

Dec 18, 2004

#1

• Dec 18, 2004

• #1

I just put a brand new shortblock from Ford in my '88 GT and I had no oil pressure at all. I hooked up a new gauge where the oil sending unit goes and it showed absolutely zero oil pressure. I checked everything I could think of, all of the oil gallery plugs are there, I have a new oil pump and pick-up. I don't know what could be causing my oil pressure to read absolutely zero. Low pressure might be more understandable, but still weird. Zero though, I just don't understand, but would appreciate all the help I can get!

 

VG30DE

Founding Member

Sep 16, 2002

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Dudley, MA

Dec 18, 2004

#2

• Dec 18, 2004

• #2

Bad/missing oil pickup tube gasket
Bad/missing/misaligned oil pump drive shaft
Oil pickup screen too tight to the oilpan
No oil in it
No oil filter on it
Pump not primed correctly

Take the distributor out, get a 1/4" drive, 1/4" 6 point socket and put it into the hole where the oil pump shaft is. Turn it counterclockwise with a rachet. You should feel a good amount of resistance because the pump is pumping. You should be able to make between 20 and 30 psi read on the gauge by turning it constantly at a fair pace by hand if the pump is working properly. Did you pour any oil into the new tube or pump before installing it? The pump cannot prime itself on its own if it doesnt have any oil in it to start off with.

 

'88Cobra

Member

Oct 21, 2004

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6

Dec 18, 2004

#3

• Dec 18, 2004

• #3

Sorry, I forgot to mention that stuff. Yes, it does have oil in it, I did prime the oil pump correctly, the gasket is there from pump to pick-up, and I checked the pump driveshaft and it is spinning the pump. I tested the pump and pick-up by themselves and they are good. I'm not sure about the pick-up being too close to the pan though. How much clearance do I need, and if it is too close how would that cause absolutely zero oil pressure, wouldn't I still get a bit of a reading?

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

95

99

PA

Dec 18, 2004

#4

• Dec 18, 2004

• #4

3/8" to 1/2" pan to pick-up clearance...if it was too tight to the pan it will suck it dry when running. At idle it would still have pressure.

When you primed the motor did oil come out at the pushrods? Did you spin it the correct way? I use a 1/2" drill and made my own priming shaft with a old distributor, you'll never prime it good enough to see pressure by hand.

 

M

manpowermustang

Member

Sep 25, 2004

228

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16

Milwaukee, Wi

Dec 18, 2004

#5

• Dec 18, 2004

• #5

You dont need much clearence. I check mine when I put it together. I had 3/4 to 1". I did not prime my oil pump like a dummy but it luckly primed it self.

 

dastang2

Active Member

Dec 11, 2003

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tx

Dec 18, 2004

#6

• Dec 18, 2004

• #6

not saying priming is not needed before you crank any rebuilt motor because it definantly is, but i don't see why the oil pump won't prime itself if you don't prime it beforehand with a drill. the oil pump doesn't know what turns it, as long as it get spins, it is going to prime. but maybe you ment, it won't prime fast enough before doing damage to the bearings while waiting to pump oil. just clearing stuff up. wow, that motor has gotta go.

 

'88Cobra

Member

Oct 21, 2004

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6

Dec 18, 2004

#7

• Dec 18, 2004

• #7

I just spun the pump by hand with the oil pan off and I have pressure now with the pan off. I guess that kind of answers my question, the pick-up must be too close! So anywhere from 3/8" to 3/4" should be good for clearance? And how can I acheive this, do I just bend my pick-up tube up or what?

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

Dec 19, 2004

#8

• Dec 19, 2004

• #8

if you have some clay or something, i would put it on the bottom of the pick up and set the pan on like it sits. measure the gap between the bottom of the tube and the bottom of the clay (which should have been smooshed to touch the bottom of the pan).

for me personally (no offense to anyone), whatever Rick says is golden (clearance question).
the repair manual should have a spec too.

good luck.

 

M

manpowermustang

Member

Sep 25, 2004

228

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Milwaukee, Wi

Dec 19, 2004

#9

• Dec 19, 2004

• #9

You can but be extra!!!!!!careful not to kinck it, plus when you bend it , it will wanna turn on a angle, the pick up screen that is. When I built my 347 I had major headaches with this. I have a 91 block and got a FMS girdle. Well the pick up tube would fit not the pan! I called summit and in the tech notes it said will not fit a 90 to 93 due to pick up tube and pan. I just scratched my head in disbeleif. I tried to make it fit and then the pan would not clear the edge of the girdle. I lucklly had a friend with a pan and pick up tube off a 86. Yep the pan is more squared in the middle and different bends in the tube.

Just thought I'd share my pain in the ass things too.

 

'88Cobra

Member

Oct 21, 2004

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6

Dec 19, 2004

#10

• Dec 19, 2004

• #10

Sound goods, thanks for the info

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

95

99

PA

Dec 19, 2004

#11

• Dec 19, 2004

• #11

I heat and bend pick-ups all the time to clear girdles and to get proper clearance, it helps a lot. Try to keep the pick-up square to the pan, I stick clay in a plastic bag so it doesn't get anywhere on the pick-up then mock it up with the gasket and pan, remove the pan carefully and see how thick it is This is of course with the motor on an engine stand.

When you prime the motor it may take a little bit. it bogs down my 1/2" drill when the pump starts to pump oil. Make sure it comes out of every pushrod

Shoot for 1/2", 1" is way to far