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JDaviesspy 02-12-2011 08:16 PM

New Oil Pump Installed, Now No Oil Pressure!!!
I just installed a new oil pump in my 4.0 6Cyl, replaced the oil pan and the 1000 bolts, filled with fresh oil and started her up to find check gauge light on and no oil pressure. I ran the engine for about 2 minutes, but did not see oil pumping up into the valves...

I checked the OP sensor and it is fine. Does it take a while to prime or do I have a bad pump?

I am truly dreading having to remove the exhaust and drop the oil pan again....

HELP!!!!! :rofl:

just4fun 02-12-2011 08:25 PM

Did u prime the pump before u installed it. Pull the spark plugs and crank the engine over. U may need to pull vavle cover while u crank it over and see if u get oil to the top of the head

JDaviesspy 02-12-2011 08:29 PM

I guess priming it would have been a good idea if I had thought about it.....which I didn't!!! Is there anyway to do this without removing it again????


just4fun 02-12-2011 08:36 PM

Im not sure if their is an oil pump priming tool that works with a drill for a jeep. It works by removing the distributor. I would pull the spark plugs so the engine cranks without compression on it and remove valve cover to see if you get oil to the top of the head and then you know it works

JDaviesspy 02-12-2011 09:03 PM

Thanks...... I found this while searching and sounds just as you instructed. I truly appreciate your advice and time!

Cheers, Jason

Priming the oil pump engine

The best way to prime an engine is with a priming rod....available through mopar performance. The distributor needs to be removed and the oil pump drive gear as well. the rod is inserted into the oil pump and attached to a reversable drill....the drill must be spun counterclockwise for the pump to prime....because that is the rotational direction of the engine.

The easy way is to pull the coil wire and disconnect the fuel pump on the inlet side before the pump. You want the fuel supply disconnected because the carb will dump raw fuel into the motor and wash down the cylinder walls....not good. When youve done those two things, simply crank the motor over for 20-30 seconds in short 10 second bursts and look at the oil pressure guage for a reading. This method works fine for mild motors with some milage on the clock. As long as the motor hasnt been sitting for a year or so it will work good. I would not recommend this procedure on a freshly rebuilt motor....those need to be primed with the method outlined above.

just4fun 02-12-2011 09:07 PM

Goodluck I hope it works

bc3_Jeep 02-12-2011 11:46 PM

I a pinch...cut down an old screwdriver and used it as a priming rod......grinding/turning the end so it would fit in my drill....

bc3_Jeep 02-13-2011 12:01 AM

One other thing that the old timers used to do......pack the oil pump full of vaseline before reassembly....... to "provide prime" from below....

JDaviesspy 02-13-2011 08:32 AM

Thanks bc3 Jeep. I should have primed it before closing everything up, but missed that important part. I will be making my tool and priming it today!

Thanks for the advice!!!!

JDaviesspy 02-13-2011 11:00 AM

So, after making the tool out of a cheap screwdriver, placing it on a reversible drill (All instructions state it must run counter clockwise), running it for 30 minutes and still no prime...... I looked at the distributor rotation chart and noticed that it rotates CLOCKWISE!!!! Flipped the switch to clockwise and the pump started to prime within 30 seconds! Will update you all when I get her up an drunning to see if it maintains good pressure!

JDaviesspy 02-13-2011 12:21 PM

All done..... Great pressure, way better than before!!!! $200 in parts and my labor. I replaced the Oil pump, oil pan seal, rear main seal (had to use 2 kits due to the first top seal sheared a little when installing) and valve cover gasket..... so far no leaks:)

Once again, Thanks for all the advice folks!!!

bc3_Jeep 02-13-2011 10:41 PM

Good news..... and THANK YOU VERY MUCH for the update...... too many times.... advice is given and no updates are forthcoming......

I sincerely hope you never have to do this again......ROTFLMAO......

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