Oil pump change
#1
Junior Member
Thread Starter
Join Date: Nov 2009
Location: Saskatoon, Saskatchewan, Canada
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
Oil pump change
Hi,
I checked on here for something about this, but no luck. On my 88 F150 4.9 2wd, how difficult would it be to change the oil pump with the engine still in the truck? Can the engine be lifted up high enough without taking it right out?
The reason I ask is because when I start the engine, it takes a few more seconds than normal for the oil pressure to build up, an when it does, a hot pressure is about 7-10 psi. When the engine is shut off, and I watch the mechanical oil guage I put in bleed-off, the pressure drops off slowly, which to me means that the bearings are still o-k in terms of clearances. I do have another 4.9 for the truck, but haven't taken it apart to check it's condition, and I need to move by the end of April so I don't have time to change engines.
Any help would be appreciated.
Thanks.
I checked on here for something about this, but no luck. On my 88 F150 4.9 2wd, how difficult would it be to change the oil pump with the engine still in the truck? Can the engine be lifted up high enough without taking it right out?
The reason I ask is because when I start the engine, it takes a few more seconds than normal for the oil pressure to build up, an when it does, a hot pressure is about 7-10 psi. When the engine is shut off, and I watch the mechanical oil guage I put in bleed-off, the pressure drops off slowly, which to me means that the bearings are still o-k in terms of clearances. I do have another 4.9 for the truck, but haven't taken it apart to check it's condition, and I need to move by the end of April so I don't have time to change engines.
Any help would be appreciated.
Thanks.
#3
April 2010 TOTM Winner
Have you changed the Oil Pressure Sending Unit?
Do you have a Quality Oil Filter installed?
The 1987-91 instrument panel Oil Pressure Gauge are known to read incorrectly.
I have seen these items indicate low oil pressure.
Does the engine knock on start up?
If it does and you replace the oil pump, while you have the engine out and the oil pan off; install main-bearings on the crankshaft.
Oil Pressure: 35-40 psi for the 4.9L at 2500 RPM / normal temperature.
Hope this helps.
Do you have a Quality Oil Filter installed?
The 1987-91 instrument panel Oil Pressure Gauge are known to read incorrectly.
I have seen these items indicate low oil pressure.
Does the engine knock on start up?
If it does and you replace the oil pump, while you have the engine out and the oil pan off; install main-bearings on the crankshaft.
Oil Pressure: 35-40 psi for the 4.9L at 2500 RPM / normal temperature.
Hope this helps.
Last edited by 1987 F-150 XLT 4x4; 03-05-2010 at 06:47 AM.
#4
Junior Member
Thread Starter
Join Date: Nov 2009
Location: Saskatoon, Saskatchewan, Canada
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
A mechanical oil pressure guage replaced the faulty original sending unit. When cold, pressure is around 35, with 20W50 in the engine.
I know I could be grasping at straws, and the engine needs to be rebuilt anyways. Was just trying to limp it along for now.
Will have to see what my other truck sounds like first when I get it going. That's my 86 F150 5.0 I got for free.
I know I could be grasping at straws, and the engine needs to be rebuilt anyways. Was just trying to limp it along for now.
Will have to see what my other truck sounds like first when I get it going. That's my 86 F150 5.0 I got for free.