F250 oil pressure question

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Gonzo - 02 Feb 2006 20:13 GMT

I have an 89 F250 diesel with a banks turbo and 60K miles on it. Nice
truck.

Recently, I was towing 9000 lbs of trailer across the Appalachians, and
my oil pressure went from the bottom of the "low" of normal to just
above the lowest mark...way below normal. I immediately pulled to the
side and killed the engine, but the oil level was fine and the oil
looked and smelled normal and since there was nothing obvious to fix, I
finished the trip.

Once home, I replaced the oil sensor sender with a pressure gauge, and
found the oil pressure to be 30psi at cruising RPM (2500rpm) and
dropped to 10psi at idle. I changed the oil (15w40 Shell rotella
before and after the change), and the pressure went to 32psi at cruise
and 20psi at idle.

The oil pressure sensor is NOT where it was when the truck was first
manufactured, but is now part of the Banks turbo retrofit: it is
located at the end of a 1/4" oil supply tube that feeds the turbo.

So, do I have a problem? Is the pressure too low? The guy that drove
the first 40K miles on this truck used it to pull a big boat, but
nothing outside the capability of this truck. Could the oil pump be
going out? The engine runs fine, doesn't smoke, pulls strong. I've
read the procedure for replacing the oil pump, and it sounds like a big
job...any other suggestions?

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websurfer - 02 Feb 2006 22:15 GMT

>I have an 89 F250 diesel with a banks turbo and 60K miles on it. Nice
> truck.
[quoted text clipped - 22 lines]
> read the procedure for replacing the oil pump, and it sounds like a big
> job...any other suggestions?

Gonzo,

The BEST place to ask this question, or research it to see if anyone has
posted about a similar situation is at this site:
http://www.thedieselstop.com/

SOMEBODY there will probably know about it if it's a known issue with this
engine. Good Luck

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Whitelightning - 02 Feb 2006 22:46 GMT

Diesels typically do not run the high oil pressures gas engines run.
Volume is
much more critical. My question would be how hot did the turbo get?
If your pulling 9000 pounds across mountains on a vehicle with an add
on
turbo kit, I would want a pyrometer on it, they measure exhaust temp
at the turbo, which
is a good indicator of if things are getting a bit too warm.. I
wouldn't mind seeing
an oil temp gauge ether.

I have always preferred Chevron Delo 400 over Rotella.

Whitelightning

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Gonzo - 03 Feb 2006 12:39 GMT

Hi, WhiteLightning.

Thanks for the helpful reply!

Yes, I have a pyro: the exhaust temp was never above 600 degrees F,
and coolant temp was never above the lowest quarter of the temp range.
When I stopped, nothing under the hood was unusually hot or smoking.

The oil supply to the banks turbo is a 1/4" braided stainless line that
runs from the side of the crank, across the exhaust manifold (!?!?!?)
with a heat-shield to protect it from the worst of the heat, to a
splitter where the pressure sensor is located.

I'm guessing the gauge on the dash is, in fact, a real sensor and not
as some folks have suggested a glorified idiot light. I base this
guess on the fact that the gauge has registered a variety of pressures,
not merely halfway-or-off.

The question is, is 30psi at the input to the banks turbo too low? I
know the oil pressure is supposed to be between 40 and 70 psi, but
where is that sensor located?

And why, Whitelightning, do you prefer Delo 400?

--JKEdward

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351CJ - 03 Feb 2006 18:37 GMT

> Hi, WhiteLightning.
>
[quoted text clipped - 13 lines]
> guess on the fact that the gauge has registered a variety of pressures,
> not merely halfway-or-off.

If it is a factory Ford oil pressure gauge, it is indeed an idiot gauge, the
signal is dampened, not just off and on.

> The question is, is 30psi at the input to the banks turbo too low? I
> know the oil pressure is supposed to be between 40 and 70 psi, but
[quoted text clipped - 3 lines]
>
> --JKEdward

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Whitelightning - 04 Feb 2006 03:19 GMT

> Hi, WhiteLightning.
>
> The question is, is 30psi at the input to the banks turbo too low? I
> know the oil pressure is supposed to be between 40 and 70 psi, but
> where is that sensor located?

I really dont know for sure on this rig you have. I know the big trucks I
have driven
30-35 psi is about average, and I've driven old Detroit 2 strokes that only
had 20psi.
I looked at Banks web page and didnt see anything about oil pressure, which
is wierd.
the 600 degrees strikes me as wierd too, seems low for pulling a load up a
grade, I would
expect to see someting in the upper 800 to 1,200 degrees F, even as much as
1,300 degrees
Even if your sensor is a foot behind the turbo, 600 degress seem low..

> And why, Whitelightning, do you prefer Delo 400?

Almost a million miles driving commercial rigs, Cats, Cummins, Detroits,
and Macks as well
as Whites back when White built engines and even Continentals. I've always
had good luck
with Chevron oils and the Delo 400 has been great since its inception.
Funny, cause I cant stand
Chevron fuels, gas or diesel. Engines I have worked on running Delo just
seem to be cleaner inside,
and have less wear. Oil seems to hold up longer based on oil sample
analysis reports on fleet trucks.
it took me a while to trust a multi-grade oil for diesels, I've always been
a 30w CD rated oil user.
But the fuel savings, and lower wear found in bearings and cylinders made a
believer out of me.
Last out fit I worked for also used the Delo in Thermoking Reefers, there is
a set up that will test
anything for weakness. Running them on cycle sentry, they might start 20-30
times a day. Small 4 cyl
Isuzu diesel engine. Other times they run constant but much of it at an
idle, then kick in to governed max,
back to idle. All depends on what's in the box as to how its set to run.
Produce needs constant air flow,
meat, ice cream, doesn't.
In the end its probably just IMHO, but its worked for me.
Whitelightning

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351CJ - 03 Feb 2006 01:17 GMT

Obviously without being there... I will just toss out a few things.

Number one, you are running a true mechanical oil gauge on board correct?
The silly IDIOT factory Ford oil pressure gauge is basically nearly useless.

You realize that working your engine hard, even without the "extra heat"
producing abilities of the banks add-ons, will greatly increase the
temperature of your engine oil, reducing it's viscosity, dropping your oil
pressure. The viscosity of engine oil has a direct effect on engine oil
pressure. Oil pressure is also affected by temperature.

I would suggest that if those are your true oil pressure readings, when hot
and working really hard the working pressure would lie somewhere in-between.
I would certainly suggest you replace the oil pump.

Finally engine oil pressure is produced between the crankshaft, and
crankshaft bearings. If the rest of your oiling system and your monitoring
system is fully functional, you may have to start looking in this area.

Good Luck

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