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Thread: Low oil pressure at high rpm's

  1. #1
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    Default Low oil pressure at high rpm's

    Ok another question for the 351w, he said while running at high rpms sometimes the oil pressure would drop off and he kick it in neutral for couple seconds and oil pressure come back up, would slowly drift off, not a hard drop. Never drop off during idle. The motor had a oil filter relocation kit on it with a fram filter, also has a double sump pan kit on it. Could the pick up tube be placed wrong in the pump or pan, maybe to high? Could the pump be bad?

    I will post pics of pan and pick up tube in the morning.

  2. #2
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    There could be several reasons:
    1) If the oil galley passages in the block or other parts (crank, push rods, etc) are partially blocked that will cause pressure issues.
    2) Might be the oil pump. There is a known issue with the Melling pumps having fitment issues where the bottom plate attaches to the body. This is a machined fit that has no gasket and the fit has been less than stellar in the last few years. If the area around the bottom of the oil pump is not submerged in oil they can suck air at this location.
    3) It could be the pick up tube too close or to far away from the bottom of the pan. I have always been told by a couple of engine builders that 3/8" is what they shoot for.
    4) It could be as simple as a faulty pressure sending unit or faulty gauge. Did he have an aftermarket mechanical or electric gauge or a stock unit?
    5) If the car is not going to be a road race car ditch the remote oil filter relocate kit and get rid of the Fram filter and put a Motorcraft FL-1A on it. I am pretty sure the remote is necessary with the Ranger install but you will not need one on your T-Bird.

    I would strongly suggest you pull the pan off the motor and inspect the main and rod bearings. If they are okay then my guess is the oil filter relocation kit and or a combination of oil pump and pick up tube placement.

    Darren

  3. #3
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    Pulled the main and rod bearings, showed sights of just breaking in just like he said.

    Check the height of pick up tube about 1 inch from bottom, I think he has the wrong bolt or mount where it bolts to main cap.

    Can I just get that part from napa or somewhere with out having to get a whole pan kit??

  4. #4
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    Typically you can just bend the pickup tube to "adjust" it but being a full 1" from the bottom of the pan almost sounds like its the wrong tube. You should be able to order a new pickup tube for a 351W that has a double sum oil pan and that should do the trick if in fact you have the right pan. I checked online and if it were me I would look at the FRPP pan kit for swapping a 351W into a Fox Mustang as our cars are virtually the same in that respect. Part number is M-6675-A58. Then again that may be what you already have on the motor but you should be able to look at pictures of the FRPP unit online and see if it compares to what you have both in the pan and the oil pump pick up tube.

    http://www.summitracing.com/parts/fm...FScV7AodMnkA9A

    Another thing worth noting is that with a 5 qt pan you CANNOT run a high volume pump or you will pump the pan dry at high rpm.

    Darren

  5. #5
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    I did some more searching on the Corral and found out that the LTD's in the mid-80's came with a 351W in them. I checked on O'Reillys website and sure enough they did and they have a replacement oil pump pickup tube:

    http://www.oreillyauto.com/site/c/se...1985&make=Ford

    Darren

  6. #6
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    Thank you I was going to go up there on Monday and check

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