ebbsspeed Posted April 17, 2016 Share Posted April 17, 2016 I will be doing an engine swap in my son's Baja this coming weekend, and have a low-mile motor out of a 2003 Outback that was totaled in a rollover. The motor hasn't run in three years, and I'm wondering if there is any way to pre-oil it to make sure the pump is primed and there is oil at the crank bearings. I am thinking I could just spin it over with the plugs out until I have pressure, or turn the motor upside down (still on the engine stand) and pour a quart or two into the oil filter mount and let it seep down into the crank. Or shouldn't I be concerned? Quote Link to comment Share on other sites More sharing options...
Bushwick Posted April 17, 2016 Share Posted April 17, 2016 I wouldn't turn it upside down with oil in it. If it's never been apart, there should still be oil in the bearings. It should spin freely with a ratchet on the crank pulley. If it doesn't, it might have gotten moisture on the rings and rusted, which I believe is bad. If ignored, the rust can probably gouge the walls and you might end up with a broken ring, etc. Would have to search on that or ask others. I'd drain the old oil, and put a decent synthetic in. Pour some directly into the oil filter, then screw that on. Can fill about 80% of the filter then screw it on. If it spins freely prior, you can try hand cranking (with plugs out for ease) once fresh oil is in and that should start circulating it. It has a rotor style oil pump. From there, you probably crank until it sees full pressure. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted April 17, 2016 Share Posted April 17, 2016 (edited) Only way to do it is to crank the engine. Like bushwick said, if you change the oil filter, fill the new one with oil before installing it. Pull the plugs out, unplug the fuel injectors and the it coil to disable fuel and spark (don't need a fire) and crank it until the oil pressure light goes out. With no plugs in it that should only take about 15-20 seconds. Edited April 17, 2016 by Fairtax4me Quote Link to comment Share on other sites More sharing options...
ebbsspeed Posted April 17, 2016 Author Share Posted April 17, 2016 OK, I'll just fill it with oil and crank it until I see pressure. I did pull the heads on the motor and replaced the head gaskets, could see a good crosshatch in the cylinders and it turned over easy so hopefully it's a decent replacement. I also did the timing belt/water pump/tensioner/idlers change, so it should be good to go for quite a while. Thanks! Quote Link to comment Share on other sites More sharing options...
AdventureSubaru Posted April 18, 2016 Share Posted April 18, 2016 (edited) If it's already turning over, you'll be fine. If no one had mentioned it yet - you'll want to put the crank pulley and drivers side cam pulley from the original motor on there. Many had differing hash marks and you'll get a no start/backfires etc without the hash marks that match the ECU in there Edited April 18, 2016 by AdventureSubaru Quote Link to comment Share on other sites More sharing options...
ccrinc Posted April 19, 2016 Share Posted April 19, 2016 Only way to do it is to crank the engine. Like bushwick said, if you change the oil filter, fill the new one with oil before installing it. Pull the plugs out, unplug the fuel injectors and the it coil to disable fuel and spark (don't need a fire) and crank it until the oil pressure light goes out. With no plugs in it that should only take about 15-20 seconds. Actually, you could just disconnect the coil pack and crank it until the oil light goes out. While I rarely disagree with Fair-guy ( ), I feel that taking out the plugs and unplugging the injectors is overkill here. Emily Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted April 19, 2016 Share Posted April 19, 2016 Before starting the brand new engine in my WRX for the first time I tried priming the engine. It turned over long enough without the oil pressure gauge registering any pressure that it spooked me into thinking I was going to damage the bearings. I pulled the spark plugs and A) the engine was able to turn over much more quickly (not having to compress anything sure helps) and the oil pressure started building within five seconds and was fully pressurized within 20 seconds. The point of my story is: If you try priming it with the spark plugs installed and it doesn't work, simply pulling the plugs may be enough to get the oil moving. YMMV... Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted April 20, 2016 Share Posted April 20, 2016 Actually, you could just disconnect the coil pack and crank it until the oil light goes out. While I rarely disagree with Fair-guy ( ), I feel that taking out the plugs and unplugging the injectors is overkill here. Emily I like fire. I just don't like it under the hood of the car I'm working on, unless the fire is on a torch that I'm controlling. I haven't yet caught a customers car on fire (don't ever plan to), but ive seen other mechanics catch cars on fire while doing compression tests. (By leaving injectors and the coil plugged in and plug wires dangling) If you don't pull the plugs, Unplugging the injectors prevents the exhaust pipe from getting pumped full of gasoline vapor that's just the right concentration to cause an explosive backfire when the engine does finally fire up. (Loud, could blow the muffler apart/fling exhaust pipe chunks out from under the car) If you do pull the plugs, unplugging injectors keeps the engine bay from getting shot fuel of fuel spray coming out of the plug holes. Unplugging the coil prevents the coil from arcing internally and shorting out. Quote Link to comment Share on other sites More sharing options...
mikaleda Posted April 20, 2016 Share Posted April 20, 2016 I have never worried about priming used motors, usually the only time you need to prime the oil system is on a rebuilt motor that's never had oil on the bearings. Personally I would get it in, fill the filter and motor with oil then start it and make sure the oil light turns of fairly quickly 30-40 seconds is the longest it should take. If you feel like pulling the plugs and disconnecting the injectors and ignitor then do it, it certainly doesn't hurt to be cautious. Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted April 20, 2016 Share Posted April 20, 2016 Pull the sparkplugs and leave the key off. Then use a jumper wire on the starter to crank the engine for 20 seconds. Put the plugs back in and fire it up. That avoids having to unplug any other connectors on the motor. Just make sure it's in park or neutral before you crank it. Removing the plugs takes off most of the load on the dry bearings because it isn't fighting compression. 2 Quote Link to comment Share on other sites More sharing options...
DaveT Posted April 20, 2016 Share Posted April 20, 2016 +1 to WoodsWagon. Quote Link to comment Share on other sites More sharing options...
forester2002s Posted April 20, 2016 Share Posted April 20, 2016 +2 to WoodsWagon Quote Link to comment Share on other sites More sharing options...
screwbaru2 Posted April 20, 2016 Share Posted April 20, 2016 (edited) Pulling the ignition / fuel pump fuse(s) disables the spark and fuel, and it's easier than disconnecting lines and connections. Edited April 20, 2016 by screwbaru2 Quote Link to comment Share on other sites More sharing options...
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