Go Back   F150online Forums > Powertrain & Mechanical > V8 Engines
Sign in using an external account
Register Forgot Password?


Welcome to F150Online Forums!
Welcome to F150Online.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the F150Online Forums community today!





Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-18-2010, 03:46 PM
Junior Member
 
Join Date: Oct 2010
Location: st thomas, Ontario, Canada
Posts: 2
5.4 lt No oil pressure with new pump??

Hi Everyone,

I'm new to the site, this is my 1st post.
I'm working on a friends 2000 F150 7700 series 4x4 5.4lt. The truck suddenly lost oil pressure while driving on the highway. The engine was shut down right away and appears to have taken no damage. I verified no oil pressure with an external gauge. This is a high mileage truck, approx 250 000miles (389000km). Upon dissassembly I found that the timing chains and guides were junk. I replaced the oil pump and timing set. I changed the oil and filter and cranked the engine with the starter to prime the pump and verify oil pressure before I put the front cover back on. When I removed the old pump I dissasembled it and found no damage. I even put about 15 inches of vacuum on the oil pressure guage port in an effort to help draw the oil into the pump with no luck. I removed the filter as well and the pump will not pick up the oil. I suspect the pickup tube is cracked, although I haven't been able to verify this as I changed the pump without removing the oil pan. As the engine lost oil pressure suddenly on the road I never suspected a broken pick up tube. I should add that when I changed the pump I cleaned out the inside of the tube and verified there was no blockage with compressed air.

Has anyone ever experienced this before? Does the starter motor spin the engine fast enough to prime this type of pump (gerotor)?

I am going to pull the oil pan later this week and see what I find. I will post my findings.

Thanks for the insight
Reply With Quote
  #2  
Old 10-19-2010, 05:09 AM
Senior Member
 
Join Date: Nov 2006
Location: So. Cal.
Vehicle: 2004 Ford F-150
Posts: 2,068
Aren't you supposed to grease the pump with something like white grease before install so that it WILL prime immediately when 1st started? I know the starter will prime a pump after an oil change because I always hold the throttle to the floor after a change to disable the injectors (about 3 seconds is all it takes) so that there's no rattle on start. I know that's not the same as a newly installed pump.
Did you mean you blew into the oil pick up tube with air into the pan? Meaning that would have verified that there wasn't an obstruction on the pickup screen.
Hasn't ever had FRAM filters used on it has it??? I wouldn't use them on a donkey wagon! Have read toooo many stories about them coming apart and clogging galleys.

Last edited by code58; 10-19-2010 at 05:12 AM.
Reply With Quote
  #3  
Old 10-19-2010, 03:15 PM
Technical Article Contributor
 
Join Date: Oct 2006
Location: Michigan
Vehicle: 1997 Ford F150 4.6
Posts: 1,630
If the chain guides nylon pads were severely worn/damaged then there could be nylon pieces blocking the pickup screen (probably the problem). Also there is a rubber "O" ring that should be seated on the pickup tube right where the pickup tube enters the pump, just above the flange where the two 8mm bolts are seated to hold the tube on the pump. If it was missing then you will not prime. No need to prime the new pump. Yes, sometimes loosening the oil filter while cranking the engine will help relieve any airlock in the system.

Last edited by DYNOTECH; 10-19-2010 at 03:18 PM.
Reply With Quote
  #4  
Old 10-22-2010, 04:38 PM
Junior Member
 
Join Date: Oct 2010
Location: st thomas, Ontario, Canada
Posts: 2
I did blow air through the tube into the pan, 90 psi shop air. The o-ring on the pickup tube is in place, however I did not grease the pump before assembly.

thanks for the replys.
Reply With Quote
Old 10-22-2010, 04:38 PM


 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


All times are GMT -4. The time now is 05:13 PM.


 
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company
Contact Us Advertising Privacy Statement Terms of Service Jobs Forum Text Archives
Emails & Contact Details