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N* oil system prime


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Hi all,

Got the last of the parts today for my 4.6 N* and getting ready to install the radiator and pour in the the fluids.

The Helms manual says to prime the engine oil system by adding oil and cranking the engine with the ICM disconnected for 30 seconds. If it does not prime, there are a couple of (apparently frustrating) options that would have to be invoked.

This seems like a long crank time for the starter and I'm wondering if it will cause problems if I need to crank for 30 seconds again to prime the pump (after letting the starter cool for a few minutes). Any comments?

If anybody's got an easier method for assuring proper priming in the event the 30 second cranking does not work, I'm all ears.

Any comments appreciated. Hope to fire it up by the weekend :)

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Did you disassemble the oil pump? If so did you lubricate it with engine oil or a light grease upon reassembly? The 1994 manual suggests white petroleum grease or Amojell .

Whether or not, I would do the following:

Remove all the sparkplugs. This will reduce the strain on the starter.

Prefill the oil filter, but leave it off for now. This will reduce restriction to the oil flow & allow air to escape from the pump housing & lines.

Place a catch pan under the oil filter adapter.

Disconnect the ICM.

Fill the engine with 8 quarts of oil. The extra half quart + the oil in the filter will be used to fill all the oil galleries and passages.

Have a helper crank the engine for 15 seconds OR until oil comes out of the oil filter adapter. If no oil appears, wait 1 minute and repeat the above. When oil comes out of the filter adapter, then you will have proof positive that the oil pump is primed.

After oil comes out of the filter adapter, install the filter.

Crank the engine for an additional 30 seconds. Wait 2 minutes, crank an additional 30 seconds. This will insure that all the oil passages are primed.

Check for leaks.

Install spark plugs.

Hook up ICM.

Fire her up.

Report results to CAddy Info!

To answer your question on hurting the starter. No, 30 seconds is not too long, as long as it is allowed to cool for a couple of minutes between crankings. However, with the oil filter off, I would reduce the time to 15 seconds max until oil starts flowing from the adapter.

Good Luck,


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I don't know if this will help, but On an old 4 cylinder Land Rover that I rebuilt, With the oil filter off, I used a trigger type oiler and pumped oil into the hole on the oil filter adapter that comes directly from the pump. This filled the pump with oil.

I don't know if the N* has the angles right for this though.

Bob B

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Other than hoping I got the mechanical timing correct, priming the oil pump is my next biggest concern. Oh man, you can really do some damage with air in the lubrication system once the engine starts up.

I took the pump apart and did the inspection on the internals (also disassembled the relief valve), then packed it full of petroleum grease and buttoned it up.

We're thinking on the same path - I did install the the four plugs on the rear head before I put the engine back in the car, but I decided it might be best to remove them for priming the oil pump.

I filled the oil filter and installed it in anticipation of reducing the air volume in the lubrication path, but it shouldn't be an issue to remove it.

I reassembled the engine with a 50/50 mix of oil and STP on the cams, main bearings, etc. The engine has been sitting for about four weeks, but I think enough lubricant has been retained on the parts so there won't be any metal-on-metal contact while the pump primes the oil passages. I also plan to squirt a little oil into the spark plug holes to be sure the cylinders don't have any dry spots.

RE: the starter - I pulled the starter down and cleaned (lots) of brush dust out of the brush case area. The brushes were about 1/2 worn, but looked fine for 130K miles of starting. I cleaned between the commutator bars (plenty of brush dust packed between them). I noted that the grease in the reduction gear housing was getting dry and added a small amount. It spins up nicely. I hope the engine will start ! :lol:

Thanks very much for the info. I'll update this weekend - hopefully with good news : :lol:


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Thanks for the insight. I didn't realize the pump drained out on shutdown.

So I'm clear - it's necessary to add an additional 8 quarts to flood the crank (total of 15 quarts)? Not that I'm planning to go this route - just curious.

I'll try a short spin w/o the ICM before firing it up just in case.

I greatly appreciate all the help from the forum members. Having the details on the N* is excellent information and has made this a wonderful learning experience.

Hope to know the results by the weekend.


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I think bbobynski knows what he is saying.....hasn't steered me wrong....ever!

Go with his advice!


Life is too short to grow up!

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Guru, Jhall & all,


My suggestion of cranking the engine with the filter off is mainly a comfort factor. It displays proof positive that the oil pump is primed.

The main difference here is that an individual (Jhall) has invested a lot of time and money into his engine. If he KNOWS that the oil pump is primed before he starts the engine for the first time the pucker factor will be greatly reduced. The factory assembles 100's of these engines weekly. They have the experience and confidence that all is assembled correctly. Furthermore if an engine in the factory fails on startup for any reason, then the company is able to absorb the loss, as a certain amount of failures are factored into the budget. In the case at hand (Jhall's), if for some reason the pump failed to prime, the owner would have to bear the expense of repairing the damage or problem.

If all was done according to the book, then I agree, there should be no problem. The preoiling procedure is mainly for the owner's piece of mind.


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