302 oil pressure too high? 75 - 52

[adunham]

I'm still trying to hunt down a noise in my engine (quiet at startup, progressively louder as engine warms). I removed the op sending unit today and hooked up a mechanical gauge. It read 75 at startup and stayed there for about 5 minutes, then slowly worked its way down to 52 at 1000 rpm. These are the same readings my electrical gauge gets in the cab. Its a fairly stock engine. Is it a red flag?

 

[SaddleUp]

Sounds about right to me. Does it drop down to the 20 to 40 range after it fully warms up? 80 PSI when it is first started is about what I look for. Then I like to see 20 psi at an idle after it's completely warmed up. I don't get worried if it drops to 10 though as long as I'm getting 10 psi for every 1000 rpms. I.E. At 3000 RPMs I want 30 psi or more.

 

[adunham]

Thanks Saddleup, I guess that's one positive piece of information at least. It doesn't ever drop into the 40 range in the cab, and it was at 52 on the mechanical gauge for a good 15 minutes.

 

[SaddleUp]

Thanks Saddleup, I guess that's one positive piece of information at least. It doesn't ever drop into the 40 range in the cab, and it was at 52 on the mechanical gauge for a good 15 minutes.

Does it go over 80 PSI at higher rpms? If so then I may worry a bit. Going over a little when it's cold wouldn't worry me but if it goes above 80 after it's warmed up I would be concerned.

 

[adunham]

Does it go over 80 PSI at higher rpms? If so then I may worry a bit. Going over a little when it's cold wouldn't worry me but if it goes above 80 after it's warmed up I would be concerned.

I've never seen 80 on this truck - 75 is pretty much the ceiling. That's on the electrical gauge of course but it seems to mimic the mechanical readings pretty well.

 

[SaddleUp]

I've never seen 80 on this truck - 75 is pretty much the ceiling. That's on the electrical gauge of course but it seems to mimic the mechanical readings pretty well.

I wouldn't worry about it being too high then. Actually sounds like you have pretty good pressure. (Better than the 96 F350 motor in mine as it does drop to 20 or so at an idle)

 

[adunham]

I wouldn't worry about it being too high then. Actually sounds like you have pretty good pressure. (Better than the 96 F350 motor in mine as it does drop to 20 or so at an idle)

Diesel? Funny thing, I'll be buying a 95-97 f-350 within the next two weeks. I test drove one Powerstroke and had it checked out by a diesel mechanic (I have zero experience with diesels). He immediately diagnosed a miss and then got into the complexities of Powerstokes and it sort of put me off of buying one used. However - he pointed me in the direction of some F-350's with Cummins 6BT 12v conversions - and that is a bulletproof setup according to everything I've read and everyone I've talked to. A fairly common swap, too. Maybe your truck wouldn't mind housing a Cummins?

 

[broncnaz]

Sounds like you may have a high volume oil pump. I have a HV pump in my bronco and get similar oil pressure readings.

 

[SaddleUp]

Diesel?

No, It's the 5.8 in my Bronco. It started life in a 96 F350. I wouldn't mind having a newer diesel in my F250 for towing though.

 

[adunham]

Sounds like you may have a high volume oil pump. I have a HV pump in my bronco and get similar oil pressure readings.

That had crossed my mind, but up until this point I haven't looked. I'll be taking the oil pan out tomorrow so I'll find out then...

 

[broncnaz]

I'm not sure if you can tell just by looking. I've never looked at the 2 side by side to see the differances. Although I think they look identicle at a glance.

 

[SaddleUp]

I'm not sure if you can tell just by looking. I've never looked at the 2 side by side to see the differances. Although I think they look identicle at a glance.

I would think sitting them side by side would be the only way to tell. Perhaps more vanes in one than the other or something.

 

[scotch]

Those numbers are a little higher than average but not scarry high.

You should be able to tell a high volume oil pump by the part number stamped on the metal tag bolted to the pump. All of the high volume pumps I have seen had a HV at the end of the part number. To compare them side by side , a high volume pump would be taller. This is because the lobe \ rotor assembly in them is taller to give the pump more volume.

Let us know what things look like when you pull the pan. What kind of noise do you have? What clues point to the bottom end?

 

[adunham]

Those numbers are a little higher than average but not scarry high.

You should be able to tell a high volume oil pump by the part number stamped on the metal tag bolted to the pump. All of the high volume pumps I have seen had a HV at the end of the part number. To compare them side by side , a high volume pump would be taller. This is because the lobe \ rotor assembly in them is taller to give the pump more volume.

Let us know what things look like when you pull the pan. What kind of noise do you have? What clues point to the bottom end?

I have no solid clues, really, that's my big problem. The noise seems to be on top, on bottom, driver's side passenger's side, everywhere. I didn't get to the pan today as I pulled the transmission off (yep, even sounds like it could be inside the bellhousing), so I'll have to do it this weekend. The part # was my plan for IDing the type of pump, I'll look for that hv.

 

[SaddleUp]

I have no solid clues, really, that's my big problem. The noise seems to be on top, on bottom, driver's side passenger's side, everywhere. I didn't get to the pan today as I pulled the transmission off (yep, even sounds like it could be inside the bellhousing), so I'll have to do it this weekend. The part # was my plan for IDing the type of pump, I'll look for that hv.

Use a long screwdriver as a probe. Put the handle against your ear and them probe around the block with the other end until you identify where the sound originates.

 

[adunham]

I've already tried the stethoscope, and I can covince myself its coming from everywhere. Is a screw driver (or broom handle) less intense?

 

[SaddleUp]

I've already tried the stethoscope, and I can covince myself its coming from everywhere. Is a screw driver (or broom handle) less intense?

Sounds like lifter clatter then. It's the hardest to tell because it clatters both in the heads and in the center of the block on the cam lobes. Not unusual though if the motor has sat awhile as the lifters will sometimes stick closed after sitting. If it's driven regularly then it would be unusual.

 

[adunham]

Sounds like lifter clatter then. It's the hardest to tell because it clatters both in the heads and in the center of the block on the cam lobes. Not unusual though if the motor has sat awhile as the lifters will sometimes stick closed after sitting. If it's driven regularly then it would be unusual.

This is what every single one looked like on the bottom, and all 16 came out easily with my fingernail under the snap ring, no lifter puller or fluids necessary to free them up. I guess my only thought is the installer didn't prime them, and the mechanism inside suffered an early demise? They all looked brand new. Too bad I put them all back and buttoned it up, because it looks like I'll be going in again...

 

[broncnaz]

Not much inside a lifter basically its only a spring with oil to help dampen it. You might have not have the correct valve lash. might need longer or shorter pushrods depending on what the clearnace is.

 

[DirtDonk]

Is the engine original? A late model EFI perhaps? What kind of sound is it? Sorry if I missed your description. If it's a light ticking from all over it's very possibly your injectors. If EFI those little injectors can make quite a racket sometimes.
I'm with SaddleUp on the tracking bit. I hate taking things apart just to find out the problem's somewhere else.
What kind of noise is it exactly?

Paul