Its time for me to mount the oil pump back on to the crankshaft. The last thing in the world I want is to get everything put back together, installed, and have this thing sucking air. So, I'd love to hear from folks that have primed one of these older model pumps. I have a '99 4.6L romeo.

In Haynes manual says to just pour oil into the pickup port, turn it a couple times, mount it, and call it a day. A book I have on rebuilding 4.6L & 5.4L engines, by George Reid, says to do the same, but pack it with assembly lube instead. I can understand the logic behind this one, but assembly lube is some seriously expensive stuff. I'm using it on the engine parts, but I'd probably have to use about $40 worth of the stuff to fill up the pump. I've even heard tell of people packing it with grease! ... not sure I'm comfortable with that one.

I'm thinking of mounting the heads, priming the pump with oil, and then mounting the pickup tube and pan, except for the bolts on the front that go into the bottom of the front cover. I figure, at that point, I could fill up the pan with oil, from the gap in front, and manually turn the crankshaft until I see oil coming out the tappets.

Does that sound feasible?

I want to be reasonably sure this thing won't just suck air when I get it back together.

-Steve
Kissimmee, FL

 

I've been told to pack them with petroleum jelly.

 

Just don't use a heavy grease like wheel bearing grease. If you used a good assembly lube you should be ok. I have always dumped at least the first 2 qts of oil all over the top end before I install the rocker covers.

 

The oil pump is not a "positive displacement" pump. I doubt you could ever get any oil to the top side by manually turning the engine. I think that is a bad idea.

Both prior suggestions sound fine though. While I'm in favor of putting 'some' oil in the pump, I think it's benefit is actually more the same as pre-lubricating ALL parts like you mention you have been doing.

So long as you have _NO_ air leaks in the pickup tube connections - you won't have any trouble with the pump picking up and getting started.

Here is a little *caution* that might be beneficial though:

https://www.f150online.com/forums/v8...ml#post5184058

I suggest completing the rebuild, then defeat ignition and run the starter for about 20-30 seconds for a couple or three times a couple minutes apart.

Good luck.

 

You don't have to defeat the ignition - just pull the fuel pump fuse.

 

10-4, that'll defeat ignition for sure. LOL


I was going to suggest holding the "Accelerator on the floor" while cranking and the ECU won't let fire - like it does on my 2004, But was afraid his might work differently and just explode!

 

The engine oil pumps I am familiar with are positive displacement pumps, just not piston type pumps you usually associate with pd pumps. That is why they have relief valves that relieve the oil to the oil pan when the pressure builds up to a setpoint controlled by the relief spring.

 

Hummm. Very valid point. The words I used were overly discriptive - kinda like the pun I poked at glc. (no malice intended).
You're right, a 'gearator' pump IS still a positive displacement pump. Even a Wankel engine is. But an oil pump doesn't employ internal wipers or scrapers like piston rings that limit leakdown - and I guess what I was trying to say is - (within the OP's meaning of 'manually' turning the engine over, I don't think oil would ever be pumped throughout the top end, at least enough to be very useful).


Would that be accurate?

 

A quick description of how the factory primes one of these engines.
The engine reaches one of the final stations on the assembly line and the correct amount of oil is installed into the engine. The engine moves to the next station and a robot pushes a three fingered coupler into the engine damper on the front of the engine. The engine is rotated by the electric motor at 800 RPM about 10 seconds. This primes the engine with oil. I have never seen an engine that didn't prime unless the sump pickup tube O ring or some other component such as a bearing etc. was missing where you had massive bleed off of oil. Hand built many engines poured 6 quarts of oil into pan and we had an air drive motor just like on the line but was counterbalanced from the ceiling so one tech could place it against the front of a newly hand built engine and rotate it at around 350 RPM to prime the engine never had any problems.So my point is just pull the fuel pump fuse as glc suggested and crank the engine until you feel confident its primed and you are set to go. Please NO grease....