1998 Ford F-150 Oil pressure Problems

UTCLAWMAN

MEMBER
1998 FORD F-150

Engine Performance problem
1998 Ford F150 6 cyl Two Wheel Drive Automatic

I have a 1998 Ford F-150 with 155,000 miles. When I fist start and run my truck, the oil pressure is fine. After about 15 to 20 minutes of driving, my oil pressure starts to flucuate, but only at idle, in gear at a stop. The longer I drive the lower it gets. Final to were it reads nothing on the dash gauge. As long as I am on the gas, or in park, the pressure is fine. Is this an oil pump problem, or bearing problem. I can hear the lifters rattle, slightly.

4 Replies

RACEFAN966

MECHANIC
5,029 POSTS

FIrst off before figuring on the worst have you changed the oil pressure sending unit to see if it is faulty or not? As for the oil pressure as you discribe it sounds more like a cam bearing problem. With cam bearing oil pressure is good cold and gets lower as the oil warms up. This is caused from lack of oil changes or weak oil pump. So first change the oil pressure sending unit if that don't help then get back to me and we will go from there.

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

Thursday, June 11th, 2009 AT 10:31 AM

UTCLAWMAN

MEMBER
3 POSTS

What is a new cam and bearing gonna set me back? Ballpark?

Was this

answer

helpful?

Yes

No

+1

Thursday, June 11th, 2009 AT 11:52 AM

UTCLAWMAN

MEMBER
3 POSTS

Could it also be a rear main bearing? If I only loose pressure when in gear, at a stop?

Was this

answer

helpful?

Yes

No

Thursday, June 11th, 2009 AT 2:50 PM

RACEFAN966

MECHANIC
5,029 POSTS

Well you should rebuild the motor to do it right but like I said before jumping to the worst replace the oil sending unit if that don't change it then get a manual oil pressure guage and see what oil pressure really is. Let me know what you find with that first and go from there.

Was this

answer

helpful?

Yes

No

+1

Friday, June 12th, 2009 AT 8:43 AM