1986 Ford F-150 oil pressure loss

SHERIFF310

MEMBER
1986 FORD F-150

Engine Mechanical problem
1986 Ford F150 6 cyl Four Wheel Drive Manual 255 K miles

Good evening. Last week I experienced an oil pressure loss. My 4.9L oil pressure used to run 50 PSI at 2300 RPM's and 22 PSI at idle while operating at normal operating temperature. Now, my pressure is fine when cold, its around 56 PSI when cold and after engine warms up, it drops to 34 PSI at 2300 RPM and 12 PSI at idle. Oil level is normal and the only other issue that occured at the same time the oil pressure dropped was the front main seal in the timing cover blew out. I had all gaskets replaced last year due to old age and leaks. The front seal was also changed at the same time. Could this be the problem why my pressure all of a sudden dropped?

6 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Do an actual oil pressure check with a mechanical gauge if its normal and no weird knocking noises replace the oil pressure switch-might want to do an engine flush.

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Monday, February 25th, 2008 AT 7:27 PM

SHERIFF310

MEMBER
5 POSTS

I forgot to add I use AutoMeter Sport Comp mechanical gauges. I am the original owner of vehicle. Oil has been changed every 3000 miles like clock work. I even went thru the effort to replace gauge thinking it may be bad. Still reads the same.