low oil pressure

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spchernandez

New Member

Jun 18, 2005

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Mar 15, 2006

#1

• Mar 15, 2006

• #1

i need some help! my oil pressure is at 25 at idle and while i am driving around. it goes up to 35 when it is a cold start, but after that it will drop, and on warm or hot days it will bottom out completely. and now i hear a knocking noise. do you think it is my oil pump, it probly has about 12,000 miles on it and it is a high volume, i think i should have stayed with the stock oil pump. any suggestions

 

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Mike92GT

Founding Member

Jan 23, 2002

583

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Florida

Mar 15, 2006

#2

• Mar 15, 2006

• #2

Is it a new motor, or did you just replace the oil pump on a high milage motor because of oil pressure issues? Most oil pressure problems are the result of worn out bearings. Once your bearing clearances open up you will loose pressure no matter what pump you put in there. Also always make sure and use a heavy duty oil pump shaft with the H/V pump, and always check pick-up to pan clearance, should be 3/8".
Hopefully your bearings don't look like this:

 

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spchernandez

New Member

Jun 18, 2005

28

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0

Mar 15, 2006

#3

• Mar 15, 2006

• #3

it is on a rebuilt motor and has about 12,000 miles on it, and i hope my bearings don't look like that. now that makes me think, should i take out the motor and check everything or not.

 

gcwh02

New Member

Jun 20, 2005

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pottstown, PA

Mar 15, 2006

#4

• Mar 15, 2006

• #4

make sure your distributor is down all the way too, if that isnt poked in fully that will give you low oil pressure.

 

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spchernandez

New Member

Jun 18, 2005

28

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Mar 15, 2006

#5

• Mar 15, 2006

• #5

yeah the distributer is all the way down i still think it may be the oil pump

 

Carney Woods

New Member

Dec 29, 2002

191

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Montreal, Quebec

Mar 15, 2006

#6

• Mar 15, 2006

• #6

I've heard that using a high volume oil pump can actually damage a stock engine. I'm not too sure but something worth researching......

 

sgarlic

Founding Member

Apr 21, 2001

3,085

1

56

Mar 16, 2006

#7

• Mar 16, 2006

• #7

I'm assuming you're using an aftermarket gauge for this? And your fluid level is correct?

What weight oil do you use? If the clearances in this motor aren't what the stock one was, you made need thicker oil anyway.. 10w40, 15w50, etc.

The knocking is probably the lifters not getting oil.

 

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Mike92GT

Founding Member

Jan 23, 2002

583

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0

Florida

Mar 16, 2006

#8

• Mar 16, 2006

• #8

What kind of guage are you using? Also is it mechanical or electric sender? What does the pressure go up to if you rev the motor? I'd double check everything with a mechanical guage before checking anything else. Have you changed the oil recently? I'd take a close look at the old oil to see if there is any metal in it. If you're hearing a knock, there is a chance you have worn or spun rod bearings.

 

Black1987Stang

Active Member

Aug 22, 2004

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37

Jersey Shore

Mar 16, 2006

#9

• Mar 16, 2006

• #9

My old motor had 10psi of oil pressure hot and about 55psi at cold warmup....ran like that for over a year, never gave me a big problem, i tried 10w30, 10w40, 20w50 still did the same really. i had a noise but that was from one rocker, oh wait it did have a real bad knocking noise around 5,000krpm and up but that had occurred just a month before i pulled the motor. and when i pulled the motor and bearings, they looked just like Mikes ^^^, it can never hurt to pull it and check it out and throw in new bearings and rings etc....but that never happens, you might end up doing a complete buildup if you already dont have a nice combo now. i said i was just gonna rering my motor and somehow ended up with a nice H/C/I combo

 

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Hoffman

New Member

Sep 11, 2004

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Mar 16, 2006

#10

• Mar 16, 2006

• #10

I don't know if this is the case but I had a fresh motor get destroyed because the front oil plugs behind the timing cover popped out. Happened about 3 hours after the initial startup. Had good oil pressure, then dropped to about 10psi warmed up. I'm doubting that it is the oil pump, I've never had any problems with the high volume pump.

 

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spchernandez

New Member

Jun 18, 2005

28

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0

Mar 16, 2006

#11

• Mar 16, 2006

• #11

i checked all the wiring and it is all good, i guess i have no choice but to pull the damn motor out of the car. i hope my bearing don't look like mikes