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Priming the oil pump

324vr4

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Apr 28, 2006
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Bozeman, Montana
I have a new engine about ready to start and I'm curious if I need to prime the oil pump before I start the engine?! I'm a little worried that if I don't the engine isn't gonna sound that pretty...so if there are any methods I should do to make this happen; it would be very helpful to hear from people who have done this! Thanks in advance!!

-Lieb-
 

VR4coop

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Sep 5, 2002
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Raynham, Ma
You shouldn't have to do that. On older muscle cars they do not have self priming pumps and I know they have to do this. But we don't have too. Your lifters may be a little ticky just from sitting, give it a few mins and I am sure it will sound fine.

Thanks
Clint
 

324vr4

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Apr 28, 2006
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Bozeman, Montana
SWEET!!! Yeah i was watching power block last weekend and they suggested that on new engines...i wasn't sure if it applied to the 4G63s....Thanks for the advice and quick post!
 

boostedinaz

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Apr 20, 2006
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Scottsdale, AZ
If you oil pump is brand new and you didn't pack it with something like vasoline, then it will not pump oil right away or not at all. Our oil pump isn't any different than most other gear type pumps.

Priming may not be "needed" but why not do it? It takes maybe 5 minutes if the motor is out of the car and can do nothing but make for a better and safer start up.

Take a drill and put a socket on the oil pump gear. Turn it until you feel drag and then have a friend watch the lifters through the oil fill cap. They should start to squirt and the oil pressure gauge will rise. Do that for a few seconds, put the timming belt on and fire it up.
 
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CP

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Aug 30, 2004
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West Simsbury, CT
I have always pulled the MPI fuse in the engine compartment and then cranked the motor for 30 seconds a few times /ubbthreads/images//graemlins/dunno.gif
 

Barnes

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Feb 9, 2003
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Richland, WA
Then perhaps you are just lucky. The one time I didn't prime the oil pump it never got pressure. I had to prime the oil pump in the car using a vacuum pump.
 

boostedinaz

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It can be done by cranking the problem is that you at still spining the crank, rods, cams, and so on with little to no oil pressure until the pumps starts working. To me this somewhat defeats the purpose of priming the motor. Plus the oil pump isn't moving very fast so the oil pressure that does build is very low. I will agree that it is better than just starting it and hoping for the best, but it is still not the ideal way to do it.

As stated above our oil pump doesn't pump air. If it is a new pump that has not been packed it will just suck air and never build oil pressure. If you are trying to prime it by just pulling the MPI I doubt it will spin over fast enough to build pressure at all.

All of these reasons are why I put a drill on the oil pump gear. It will spin the pump fast enough to create suction if it wasn't packed, it will also spin fast enough to get good oil pressure not just enough, and the best part is that it will feed all the bearing very well before the engine rotates at all.

Again just my opinion, but I wouldn't build a nice new motor and leave things any at all to chance.
 
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Rausch

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Dec 21, 2004
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Cleveland, OH
Quote:
you at still spining the crank, rods, cams, and so on with little to no oil pressure until the pumps starts working.

true, but thats essentially what the assembly lube is for as well...i think gettting good oil pressure would be the best, but the assembly process *should* take into account the lack of oil pressure on initial start up. now, not packing the pump, or not getting pressure after the motor has been turning is a whole 'nother story...
 
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Dialcaliper

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Jun 22, 2007
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Mountain View, CA
The oil pump is low enough in the case that it should start pumping oil right away.

However, cranking it over with the injectors off for a bit is better than just starting it up and running it at 800-1000 RPM.

Do *not* forget that if you are running an external oil cooler, after the initial warmup, you need to top off the oil unless you filled the oil cooler beforehand.
 

grocery_getter

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Jun 20, 2004
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Kent - industrial suburbs of Seattle, WA
If you are cranking the starter to prime the oil pump you have to take out the MPI fuse so you wont be washing the wall with fuel. Don't forget to take all 4 plugs out too. That way there will be no compression in the cylinder and no real load on the rod and main bearings.
 

Flip4G63

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Aug 28, 2007
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1,160
Location
Abilene Tx
You can also use the drill meathod to prime the pump. (spin the pully untill you get it where you want it)

and as said above a few times pull the MPI fuse, and plugs and crank it awhile..



Prime your pump!
 

CO VR4

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Jul 13, 2002
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2,019
Location
Colorado
Preluber or accusump are best, drill method 2nd best, because they deliver full pressure BEFORE you crank...

Why spend a bunch on your rebuild and then take a chance that something starves for lube while you're trying to get the pump to prime...?
 

BluFalcon

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Jan 20, 2002
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Location
Wichita, KS
I've always primed my engines while they're on the stand with a drill and a socket. Once they're in the car, I crank it over with the MPI fuse and plugs pulled until I see it build some pressure. A little too cautious perhaps, but why take the chance?
 
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