We went on a short trip Saturday and I plugged my scanner in to watch the real time data while we drove...VERY interesting stuff!! Anyway, at idle the oil pressure read 8-10psi and going about 65mph it got up to 30-35. To me this sounds a little low, but then I don't really know what this engine normally runs. Does this sound right?

1998 E-350 15 pass.
V10 E4OD 3.73
Pulling 4000 lb trailer with hardly no drag to it

 

First, let me say that you and I are measuring at two different points, but it shouldn't matter that much...

I have installed a mechanical AutoMeter oil pressure gauge and I plugged into the oil gallery hole on the rear of the driver's side head. My pressure indications are as follows:

Cold engine: 80 psi at startup

Warm engine: 29 psi at idle
40 - 45 psi at 65 mph

BTW, I am running Mobil 1 5W-30.


Best regards,

Jeff

 

This is very interesting... I didn't know a scan tool could get the oil pressure. Do you have a guage on the dash, and does it move with RPM?

The reason I ask is my '01 (and most other Fords I guess) have an "idiot light" for a guage. It's either nothing, or just over half-way. It's not a real pressure sender, just a reverse (normally open) idiot-light sender.

On another note: Don't trust scan tools for real values. Always ALWAYS check via mechanical means. I found this out with my AutoTap. It seems reference values can be out of whack, the manufacturer didn't get the right spec from Ford, the value you're looking at may not really be the oil pressure. It's all based on computer codes, VIN # or all sorts of other things.

ak

 

No it doesn't have a real guage that actually works. The sender installed by ford will actually read the real pressure because the ECU has to know all of the exact values to control the engine properly. I don't know why they wouldn't just go ahead and put a real guage on there. I guess some people get scared if the guages on their dash move around all the time? - I dunno.
It's most probably that my scan tool isn't exactly correct because I'm sure if oil pressure was as low as that the engine wouldn't have made it to 80,000 miles. I was just wondering. Thanks for your responces!!

BTW. According to my scanner and watching engine load percentage. The A/C uses 4% of engine power. And 16% more is lost to other utilities, friction, and heat. And then you have about 18% lost through the drivetrain....We're only getting 60-70% if that of what the engine actually produces to the rear wheels!!

 

Interesting - I don't think the ECU has to see oil pressure. Or if it does at all. That's why I'm very interested in this.

You sure it's not tranny pump pressure?

How many miles are on the motor?

ak

 

You know...now that you mentioned it the scanner did say "line pressure", but because it went up and down with rpm's I thought it had to be the oil pressure. I guess the tranny pump would go up and down like this also wouldn't it? Sorry about the scare.

The engine has 80,550 miles and running strong!! We're fixing to take a trip with it pulling an 8500 pound travel trailer from lower South Carolina up to where SC, NC, and GA meet. It's a real nice climb up for the last ten miles (30 minutes)!! It did great last time and I don't expect any trouble this time either.

 

then that IS the tranny "line pressure"

ak