oil pressure question - Diesel Forum

redbeard85 · 11-22-2005, 11:29 PM

I've noticed when getting off the highway, my oil pressure drops to around 5-10 psi. It doesn't matter if it's hot or cold out It never has any problems and as soon as you touch the throttle, it jumps back up. Is there a need for concern? Should I invest in an oil cooler? I run Rotella 15W-40 and a Motorcraft filter, if that makes any difference.

Also, I drive about 125 miles to work and back per week, is it normal for me to add a quart of oil per week?

Thanks

Trevor in MO

cdnsarguy · 11-23-2005, 12:31 AM

If your engine is returning to idle 10 psi is allowed, at 3000rpm it should be 40-70. The 6.9 is known to be an oil user but over filling can cause an excess.....

A friend from Ford posted this........

DieselDon

Oil consumption, and the proper checking of the oil levels in Ford diesels comes up periodically. Ford dipsticks are calibrated for hot oil. The 10 quarts in the IDI engines expand about 1/2 to 3/4 of a quart as the oil heats up, and contracts the same amout after cooling. If you check the oil first thing in the morning ( which I grew up doing ) the engines will all indicate oils level below full, but when checked hot, will ( after a 10 minute drain time ) the oil level is usually at full. If you are checking the oil cold, and keeping the level at full, you are actually over filling the engine which will burn of the extra rapidly.

Suggestion: Check oil hot after 10 minute drain time.
Don't add until level reaches add line ( 2 quarts ).

In my days at Ford this often cured, or at least improved, the apparent oil consumption complaints.

Joe Mc · 11-23-2005, 03:04 PM

And when it reaches the add line, only add 1 quart.(From the TSB)

jdkline · 11-23-2005, 06:12 PM

Yeah 1 qt per week @ 125 miles per day is 125 X5 is a qt per 625 miles. No worries with consumption. The biggest concern is that the oil pressure be minimum 30 PSI at 3000 RPM on '83- 85 and 40 '86 and later (don't know why they chamged the spec in '86)...

redbeard85 · 11-23-2005, 09:51 PM

Actually, it's only about 25 miles per day, 125 per week. The oil pressure stays above 30 psi on the highway(60-65mph).

Trevor in MO