no oil pressure
Thread Starter
|
New User
Joined: Jul 2003
Posts: 16
Likes: 0
no oil pressure
Hey guys, I need some advice. I have a 78 f-250, 400 2v,manual trans. I had a noise in the trans, so I swapped it out. Take on test drive, noise gone,great, this thing is getting closer. Oh no,now I have no oil psi.,back to the garage. Ok no big deal,hook up manual gauge,no oil psi. drop pan & install new high volumn pump,no oil psi. verify shaft engauged in both ends, dist. & pump,ok. remove filter & cut open. no metal. set up drill to run pump with dizzy out & filter off. shooting oil out side,ok. wont build psi with all hooked up. Could this be cam bearings???,debris in passages,Ive begun running wire through passages & have dropped a couple mains & rod bearings, not bad. HELP!, I love this truck & I will win. But, you guys have all this knowledge, so I was hoping somebody out there could help. I really hate to pull it out. I had to pull the heads to repair the rotton exhaust manifolds & had just gotton all that done before the trans.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
No oil pressure means that either your pump is not pumping or there is an escape path for the oil that could be a bad bearing or lifter or oil gallery plug. Or a restriction in a passage could restrict the flow enuf that you register nothing at the other end of the engine. Check to see if you are getting pressure at the oil passage port next to the filter.
Lead Driver
Joined: Nov 2000
Posts: 6,643
Likes: 351
From: Albuquerque
Was the engine making any noise when the oil pressure was zero?
I always look for the simple things first. You changed the tranny and then it happened. Where did you hook the mech. gauge? Have you checked the sending unit and it's wire? If your pressure was indeed zero the engine should have been making a lot of noise.
I always look for the simple things first. You changed the tranny and then it happened. Where did you hook the mech. gauge? Have you checked the sending unit and it's wire? If your pressure was indeed zero the engine should have been making a lot of noise.
Thread Starter
|
New User
Joined: Jul 2003
Posts: 16
Likes: 0
Thanks guys for responding, Yea I had noise alright, luckily I was close to home,about two blocks when I noticed it ticking. I connected the gauge to the port for the sender to eliminate the sender & wiring. No doubt about the oil pressure,0. I did have the filter off & ran the drill & had oil out passage at the filter base. I think the bottom end is getting oil, but , the top end , i dont think so. When i had the heads off i noticed the engine was very clean inside, as if had recent rebuild. I've had the truck for years, but only push snow with it. I've always had great oil psi. The engine did lean back when i had the tranny out("floor jack leaks off"). I guess I'll peel the intake off & repressurize the oil gally & look for bleed off or try to find the restriction. I want to restore the truck soon but wanted the driveline all good before i tear it down. I am about to clean the garage & strip it down. Again thanks guys, any help is greatly appreceiated. 78 f-250 4x4 dana 60s(4:10)np205, np435, 400, dual sway control, high output heater, xlt. Thanks again & what a great site this is! Oneford
Lead Driver
Joined: Nov 2000
Posts: 6,643
Likes: 351
From: Albuquerque
thats an odd situation. I have never seen an engine suddenly plug up the oil passages. Especially if it's clean inside as you say. It's possible the oil pump lost prime or the filter plugged in which case you have already primed it. I would throw on another filter and try spinning with the drill again.
Good luck!
Good luck!
Thread Starter
|
New User
Joined: Jul 2003
Posts: 16
Likes: 0
Well i done that & only use motorcraft filters. I may have taken out a lifter due to valve adjust or something when i had the heads off. It is strange it developed all of the sudden, & i had ran the engine quite a bit before doing the tranny repair. Im thinking of plumbing up the oil pump with pipe & run out of bucket, so I can have the pan off & try to see were the loss is,or possibly the restriction,yea it will be messy. I will probably spend maybe 10 hours more on it & then its coming out. Oh by the way,nice truck beartracks, looks like you do good work! And thanks again to all you guys.
Trending Topics
New User
Joined: Jun 2003
Posts: 18
Likes: 0
From: Georgia
I had a similar problem with rapid, complete loss of oil pressure in my 400 1982. I believe the cause was a plugged oil pump pickup because after sitting for a few minutes it would start and develop pressure. A few more miles down the road and it would lose pressure again. All I did was run some tranny fluid in the oil to clean it out , oil and filter change and it has run fine since.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Posting Guru
Joined: Aug 2002
Posts: 1,214
Likes: 2
From: Minneapolis, MN
Just for something else to check, my 429CJ would periodically punch a pushrod through a rocker and the lifter would pop out. Lumpy cam, so I didn't notice it miss but the oil pressure would drop to zero.
Thread Starter
|
New User
Joined: Jul 2003
Posts: 16
Likes: 0
Well, I feel stupid. Pulled the right valve cover off & there it was ,2 rear rockers loose & pushtubes bent. Pulled the intake off & found one of the lifters had come apart. I had pulled the left off when this happened, because I had one of the rocker bolts come loose on that side after having the heads off. Thought the ticking was a result of the loss of oil pressure, not the cause of the loss of oil psi. Macguyver & Torque1st you hit the nail on the head. Now this weekend ill put her back together! Thanks guys, you are a big help.