Priming oil pump

[dragnet]

Just putting together the front cover and oil pump. I've been told I have to prime the new oil pump. Some searching has mentioned cam lube or even petroleum jelly. A friend of mine recommended using some molly transmission aditive. Any advice on the best approach to priming a new oil pump in a 4.6 V8?

Thanks in advance.

 

[MUSKYMAN]

the 4.6 has a crank driven pump and does not need to be primed.

the only pump that needs to be primed the one that is driven by the distributor shaft.

 

[dragnet]

I guess priming is not the right word. Given that the pump gears are new is a coating of regular oil enough to stop them from being damaged when the motor first fires?

The front cover actually came from the dealer with a warning tag attached to it specifying that the pump must be primed before running the engine. Yet my dealer states the same as you; that the oil pump does not need to be primed.

 

[ptschram]

This has been a topic of discussion with Mr. Musky and I.

On one single, solitary occasion, I encountered a 4.0 that simply would not prime. I tried the Vaseline method to no avail and found that white lube and 90 wt. make a great oil pump priming material. It also helps greatly if you pre-fill the oil cooler/lines and the filter to minimize the time before oil pressure is fed to the main and rod bearings.

 

[ratboy]

This has been a topic of discussion with Mr. Musky and I.

On one single, solitary occasion, I encountered a 4.0 that simply would not prime. I tried the Vaseline method to no avail and found that white lube and 90 wt. make a great oil pump priming material. It also helps greatly if you pre-fill the oil cooler/lines and the filter to minimize the time before oil pressure is fed to the main and rod bearings.

i second that

 

[dragnet]

By white lube are you refering to something like a lithium grease?

 

[ptschram]

By white lube are you refering to something like a lithium grease?

Yes. I'm sure there is a reason why it isn't hte best material for this purpose, but I figure I use enough of it (almost an entire tube yesterday) when pre-lubing brand new enignes that it shouldn't be a problem.

I must say that it is a rarity fo the crank driven pumps to not prime. I had one engine that had sat in a parts truck for a few years that primed itself instantly and every time I've done a cam on a GEMS (or late Lucas) they have self-primed. The one tat didn't was a boneyard engine and I have no idea as to its provenance.

God luck. It is frustrating when an engine fires on barely 15' of crank revolution only to find no oil pressure.

 

[David Despain]

white grease:
http://www.lubriplate.com/products/greases/no-105-motor-assembly-grease.html

lubriplate 105. i have used this stuff when assembling hundreds of motors and of parts of motor assemblies. granted these were airplane engines but never the less it works well. i think it would work well packed into the oil pump cavity

 

[ptschram]

white grease:
http://www.lubriplate.com/products/greases/no-105-motor-assembly-grease.html

lubriplate 105. i have used this stuff when assembling hundreds of motors and of parts of motor assemblies. granted these were airplane engines but never the less it works well. i think it would work well packed into the oil pump cavity

That's the stuff! I learned about Lubriplate working on aircraft engines as well. I wasn't sure about the viscosity, hence my cutting it with 90 wt.

 

[dragnet]

Thanks again guys. This forum has been a great source of info.

 

[MUSKYMAN]

if you are really worried about it priming just pull the fuel pump or fuel injectors fuse and crank the engine for 30-40 seconds and the oil pressure light will go off.

then replace the fuse and fire the motor.

 

[xengineguy]

Why not actually prime the engine, every new engine or rebuilt engine I have installed was primed..On dry sump motors we spin the pump until we have oil pressure,then rotate the engine a few times. On wet sump motors I use a dummy distributor to spin the pump untill we get pressure then rotate the engine. Wet sump or dry sumps W/O a provision to rotate the pump alone (like some rovers) I pressurize the oil galley thru a galley plug or the pressure sensor port. An old fire extinguisher filled with oil works great for this.

 

[MUSKYMAN]

because the factory has fired 10's of thousands of these engines and feels that a correctly assembled engine with engine assembly lube in all the correct places will make oil pressure fast enough to prevent damage.

the crank mounted oil pumps make full pressure in 30 seconds and like I said they will make pressure by just cranking them with starting them, going through all kinds of other steps apears to be over kill.

The ones that use a distributor driven pump do need priming and also suffer from lost primes from time to time at oil change and Rover went away from that style pump to prevent those problems.

with the exception of engines with plugged oil pick ups the crank driven pumps really produce full pressure fast.

but hey do what ever you feel is best for your motor.

 

[ptschram]

Thom:
That's all fine and dandy until you encounter the ONE that won't prime. On the one I dealt with that wouldn't prime, the pan and pick-up had been off and were scrupulously clean.

As in everything in life, there might just be that one outlier.

 

[MUSKYMAN]

Thom:
That's all fine and dandy until you encounter the ONE that won't prime. On the one I dealt with that wouldn't prime, the pan and pick-up had been off and were scrupulously clean.

As in everything in life, there might just be that one outlier.

my gut would say that that one pump had clearence issues that prevented it from creating enough suction to draw the oil.