oil pressure concern.. help!

[99rangerbeast]

99 ranger 4x2 3.0 flexfuel automatic 118,000 miles. My oem oil gauge zeros out in drive with brakes pressed so i put a mechanical gauge to check actual pressure. when warmed up it idles at around 10psi. 0-5 psi in drive with brake pressed and around 30 psi at cruising speeds. it has fresh oil change and runs fine. cel is on but code reads egr out of range. only noise engine makes is slight lifter tapping at about 1500 rpms. would a failing cam syncro cause oil pressure to drop at low rpms or should i look more into replacing the oil pump? i have checked for noises with a mechanics stethoscope and hear no chirping syncro. any ideas what to do first?

 

[Rearanger]

The 10psi at idle and 30psi at cruise sounds ok to me. What pressure are you looking for? If presssure drops when in gear and brake on maybe your idle is too low. What oil grade?

 

[99rangerbeast]

i'm running 10-30. idle is fine. it just pegs at zero on the mechanical gauge when in gear.. like at stopsign or redlight. i know that can't be good over and over. once it reaches operating temp it idles at around 1000 rpm and oil is between 5-10psi in park. 0-5 in gear.
the engine runs too good to have such low oil pressure. debating tackling cam syncro first since it is easier. scared to drive it in city because of all the stop and go traffic.

 

[Beef52751]

You should have around 30 at idle and 60 cruising IMO, but i dont have a mech. guage so i dont know what mine is doing. i doubt it would be thew cam synchro. probally the oil pump, i know small block fords always had problems keeping oil pressure becuase of the pump.
Beef

 

[Rearanger]

it just pegs at zero on the mechanical gauge when in gear..

The gauge may not read very accurately at low pressures. What brand gauge? Using another gauge with short pressure line as a check might not hurt.

You should have around 30 at idle and 60 cruising IMO

Maybe at cold temps but not at operating temperature.

 

[TomB1269]

The gauge may not read very accurately at low pressures. What brand gauge? Using another gauge with short pressure line as a check might not hurt.



Maybe at cold temps but not at operating temperature.

Agreed, 30 at idle 60 at crusie when cold. As for the pressure a warm, check PCV valve and crank case vent tube going to intake hose for filter to TB for oil. It sounds as if you have heavy blow by. You may not see a lot of oil smoke if your scrapper rings and oil rings are in tacked. But if you have worn compression rings you are adding air pressure to the oil pan which will slow oil flow. This additional pressure slows by carring oil out the crank case breather. You should also see substantailly low compression reads if you do a compression test. If this is the case, your options:
A. Run it until it dies - may run great for years like this.
B. Try CD2 additive - may help recondition cylinder walls and limit blow- by, short term fix, as you would need to add at every oil
change, at $5 or $6 a can gets expensive
C. Pull engine, hone cylinders and replace rings - long term but expensive as at a minimum you would need to polish crank, replace bearings which would run $700 at least, but a great opporunity for some internal mods that will provide real results.
Good Luck............

 

[99rangerbeast]

thanks for the posts. A little more info about the truck.. i just recently purchased it and had to replace the head gaskets. had one burnt valve also. cylinders looked good when heads were off. still had factory hone marks. heads are totally redone. pcv valve and system looked clean.. pcv rattles fine. i think gauge is fine. not sure of the brand tho. prolly a cheapo. lol. the reason i hooked up a mechanical gauge is because the idiot oem gauge would peg out at zero at low rpm's and cause the check gauge light to come on. i work at a parts store and get the parts at cost and have mechanic handy that helps me so i haven't put much money into it yet. that and i got it for 1500 bux with a 3" lift, 31" tires and westin accessories. i am willing to put a good bit into it to get it right. i am running a purolator filter with 10-30 oil. i may change to a motorcraft filter and get a better gauge before doing a tear down. how many of you are running mech gauges and what is your idle and cruise temps at operating temps?

 

[GMWIGGS]

I use sunpro guages, they are kind of cheapos IMO. They seem to function accurately so I trust what they say. I'm running 10w40 with K&N filter (I like the nut on the end). My oil pressure is around 42 PSI at 2500 rpms and 18 PSI at Idle in park at 185* temp. Cruising about 55-60 mph oil pressure runs around 35-38 PSI.

The spec for this motor is between 40 - 60 PSI at 2500 rpms at operating temperature.

Fords are notorius for having lower oil pressure, at least in my experience. Good luck!

 

[Rearanger]

I use sunpro guages, They seem to function accurately so I trust what they say.

Unless gauges are certified it is hard to say how accurate they are. Manufacturer can list % accuracy on gauge info. Oil pressure usually doesn't have to be that accurate though.

I'm running 10w40. My oil pressure is around 42 PSI at 2500 rpms and 18 PSI at Idle in park at 185* temp. Cruising about 55-60 mph oil pressure runs around 35-38 PSI.

There's no reason to run oil that heavy in a street machine. It may even do more harm by reduced flow (especially in cold temps) in bearing surfaces. Don't forget PRESSURE IS A MEASUREMENT OF RESISTANCE and using heavier oil does not create more pressure it just shows a higher resistance to flow. Installing a higher flow pump should create higher pressure (actually pressure drop) from higher flow.

I'm testing 0w-30 to get better cold temp flow on start-up and will do a used oil analysis at 3K miles to compare to the 5w-20 I was using. Thicker oil does not mean better protection.

 

[GMWIGGS]

There's no reason to run oil that heavy in a street machine. It may even do more harm by reduced flow (especially in cold temps) in bearing surfaces. Don't forget PRESSURE IS A MEASUREMENT OF RESISTANCE and using heavier oil does not create more pressure it just shows a higher resistance to flow. Installing a higher flow pump should create higher pressure (actually pressure drop) from higher flow.

I'm testing 0w-30 to get better cold temp flow on start-up and will do a used oil analysis at 3K miles to compare to the 5w-20 I was using. Thicker oil does not mean better protection.

You're not the first to tell me that and you are probably absolutely correct. I do a lot of towing with my truck. After towing 3500 lbs for 20 miles it really starts to thin the oil down at least according to the gauge (which may or may not be accurate). I just feel better with a little thicker oil that don't drop off so much pressure after a hard tow. A comfort thing I suppose. But in the end you are correct, 5w30 would serve me just fine. BTW I use Mobil 1 syn, I tend to go a little overboard sometimes.

Oh I would like to see the results of your UOA, I've never done that before, but am interested to see your results.

To the OP: sorry to derail your thread I hope you get all sorted out!

 

[Rearanger]

GMWIGGS, I would suggest Mobil1 0w-40 instead of the 10w, that will give you the cold temp viscosity with high temp protection(?). If you PM me with your email I can scan and email my UOAs for the Ranger. Not sure what use they will be as each UOA is specific to vehicle and driving habits but I'll be glad to share info. I have not been happy with lead wear and am hoping the
0w-30 Mobil1 will reduce it after using Red Line 5w-20.

 

[Rearanger]

how many of you are running mech gauges and what is your idle and cruise temps at operating temps?

I run an Auto Meter electric, pressure should be pressure, no matter how it's measured. My idle (750rpm) is about 15psi and my cruise (2500rpm) is about 37psi. I'm using Mobil1 0w-30.