Setright Posted December 16, 2004 Share Posted December 16, 2004 I have been confronted with a theory that seems a little absurd to me: After changing oil, disconnect the crank sensor and crank the engine until the oil pressure light goes out. The idea is to ensure that all the oil galleries are primed before you allow the ignition to come on. Yes, the filter is primed during the oil change. The word is that "Subaru's are notorious for throwing a big end bearing after oil changes". Anyone ever heard of this???????? Quote Link to comment Share on other sites More sharing options...
DerFahrer Posted December 16, 2004 Share Posted December 16, 2004 Subarus rarely have any bottom-end problems period, so that's garbage. When you change your oil, you should do it when the engine and oil is hot, because hot oil will drain better, that should be a universally-known fact. Obviously you're not going to get every last drop of oil out of the engine, you're going to have probably a whole quart sitting in various places in the crankcase, the heads, the oil pump, etc. etc. Your bearings should be coated with enough of a residue, especially after it was just running, to lubricate them upon startup until the oil pressure builds out of the new filter. If you wanted to prime the engine after the oil change, that wouldn't be detrimental in the slightest, knock yourself out. But why would you disconnect the crank sensor??? What about the coilpack Quote Link to comment Share on other sites More sharing options...
99obw Posted December 16, 2004 Share Posted December 16, 2004 If you want to prime remove the fuel pump fuse. I just fill the oil filter fully and start the engine without priming. Quote Link to comment Share on other sites More sharing options...
cookie Posted December 16, 2004 Share Posted December 16, 2004 me to start doing that. I used to prime them right after a rebuild for the first start. You might cause your engine to throw a code on a modern motor. Quote Link to comment Share on other sites More sharing options...
coloradosubarules Posted December 16, 2004 Share Posted December 16, 2004 After changing the oil I remove the cooling fans and the put a socket on the crank and turn it over a couple hundred times. Then I go and stick needdles in my eyes for being so stupid. I just fill the filter and pan and then fire it up. The split second it takes for the system to prime shouldn't harm it. I don't know if anyone else does this but I remove the 2 plugs in the oil pump when changing the oil so I get more out. Quote Link to comment Share on other sites More sharing options...
Gnuman Posted December 17, 2004 Share Posted December 17, 2004 I change the oil every 3,000 to 5,000 miles and it comes out still pretty clean. I don't worry about the quart that may be in the nooks and crannies, as it is still fairly good oil. I also change the oil "warm" (at operating temp) so it flows better. One thing I love about my Subie is that I don't even have to jack the car up to change the oil. Park on level ground, and I can crawl under far enough to reach everything just fine, and the catch pan fits great too. THis means that there is less distance for the oil to travel making it less messy from missing the catch pan. Also with the oil filter on the bottom, away from other components, there is little of ro chnace of the oil from the filter area "splashing" on things on the way to the catch pan. This is just one more thing I love about my Subie. Quote Link to comment Share on other sites More sharing options...
MorganM Posted December 17, 2004 Share Posted December 17, 2004 Fill your oil filter up with oil before reinstalling. Fill it up SEVERAL times as the filter soaks up over a half quart! You will get oil pressure almost instantly. Whoever told you it would do that is way WAY too paranoid. They prolly wear rubber gloves when changing oil too.:-p Cuz youll get CANCER FROM THAT DIRTY OIL! Quote Link to comment Share on other sites More sharing options...
brus brother Posted December 17, 2004 Share Posted December 17, 2004 After changing the oil I remove the cooling fans and the put a socket on the crank and turn it over a couple hundred times. Then I go and stick needdles in my eyes for being so stupid. I just fill the filter and pan and then fire it up. The split second it takes for the system to prime shouldn't harm it. I don't know if anyone else does this but I remove the 2 plugs in the oil pump when changing the oil so I get more out. I follow this same routine. Quote Link to comment Share on other sites More sharing options...
coloradosubarules Posted December 17, 2004 Share Posted December 17, 2004 Gee thanks Brus...I'll remember that when I get that new worm virus in my next e-mail....let me make sure I have your e-mail dress correct.... Oil is known to the state of California to cause cancer with prolonged use. Quote Link to comment Share on other sites More sharing options...
Frank B Posted December 17, 2004 Share Posted December 17, 2004 If you run the engine to get the oil up to temp, there will be more oil clinging to the various parts in the engine(since it was just running) then there would be when you start your car in the morning, after the oil had all night to drain, or after work when it had all day. So unless you prime it every time before start up............ Quote Link to comment Share on other sites More sharing options...
Snowman Posted December 17, 2004 Share Posted December 17, 2004 That sounds pretty worthless to me too. What happens every time you start your engine? The oil in the bearings doesn't drain out when you change the oil, and if the engine is not loaded, that little bit of oil that remains will be more than enough to keep everything lubed up until the new oil can get there. If you prime the filter well, the pressure buildup time will be a couple of milliseconds longer than on a normal startup, and if you make sure that both then engine and the oil going into it are warm, the time will probably be significantly less than during cold starts. Where did you hear such a theory? Quote Link to comment Share on other sites More sharing options...
Setright Posted December 17, 2004 Author Share Posted December 17, 2004 Thanks guys, for some reason the lads on Imprezasport.net seem to believe this theory. I was hoping you would support me :-) I would also worry about unburnt fuel reaching the catalyst during such a dry-crank manouvre. Although the missing crank sensor would hopefully mean that the ECU keeps the injectors shut. Check it out: http://www.imprezasport.net/forums/index.php?showtopic=4036 Quote Link to comment Share on other sites More sharing options...
blitz Posted December 17, 2004 Share Posted December 17, 2004 While most fuel injected cars start right up with a click of the key, Subaru's have that distinctive 1.5 sec. crank-before-fire characteristic. I've always assumed that this was another one of Subaru's strategies toward achieving long engine life by way of giving 5-6 priming revolutions before light-off. Quote Link to comment Share on other sites More sharing options...
Subarunation 713 Posted December 17, 2004 Share Posted December 17, 2004 What is all of this CRAZY talk about changing oil? Don't you just put gas in them and go? ;-) Quote Link to comment Share on other sites More sharing options...
99obw Posted December 17, 2004 Share Posted December 17, 2004 What is all of this CRAZY talk about changing oil? Don't you just put gas in them and go? ;-) You must be referring to my wife. Oil in the engine, air in the tires? What do you mean?! LOL Quote Link to comment Share on other sites More sharing options...
Setright Posted December 17, 2004 Author Share Posted December 17, 2004 Good point Blitz! I will use that as my argument if anyone complains that my car is "slow" to start. Thanks man :-) Quote Link to comment Share on other sites More sharing options...
Frank B Posted December 18, 2004 Share Posted December 18, 2004 MAYBE, if you had a turbo charged car, with an external oil cooler, and/or a relocated oil filter, and had several feet of oil lines that all together may hold a quart or two, and you loosened every oil line to get out every last drop....... it MAY be good to prime the engine to get oil in all the components before starting and reving the engine.......maybe. Quote Link to comment Share on other sites More sharing options...
blitz Posted December 18, 2004 Share Posted December 18, 2004 Good point Blitz! I will use that as my argument if anyone complains that my car is "slow" to start. Thanks man :-) My Dodge (Mitsubishi) Colt used to fire with a just the slightest, momentary blip of the key ...hot or cold. It's fart-fig-newton (fahrfehgnugen?) for the driver, but apparently hell on the motor. I wish I could remember more clearly, but I believe it was a G.M. paper within the last year or so that was speaking in regards to up-rated motor oil low-temp flow requirements specifically for the purpose of addressing the long-term wear patterns (damage) caused to F.I. engines as a result of their eagerness to fire instantly at arctic temps. Quote Link to comment Share on other sites More sharing options...
Snowman Posted December 18, 2004 Share Posted December 18, 2004 Hmmmm.... so maybe it was actually a GOOD thing that my car took like 30 seconds to cold start when it had that POS Weber carb on there! Quote Link to comment Share on other sites More sharing options...
Setright Posted December 20, 2004 Author Share Posted December 20, 2004 All in all, it sounds like Subaru haven't lost all their old charm. My Impreza was over two seconds starting up on a frosty morning recently. What does the ECU do? Determine temp? Oil pressure? Time the engine has stood still? Before sending the OK signal to the injectors? What a shame that a really cold start is accompanied by piston slap ;-) Quote Link to comment Share on other sites More sharing options...
cookie Posted December 20, 2004 Share Posted December 20, 2004 in Japan to see if it is OK to start yet. Quote Link to comment Share on other sites More sharing options...
Gnuman Posted December 21, 2004 Share Posted December 21, 2004 Subarus have to check with the home office in Japan to see if it is OK to start yet. Cookie, you owe me a new keyboard. . . Quote Link to comment Share on other sites More sharing options...
Gnuman Posted December 21, 2004 Share Posted December 21, 2004 Say, I just realised that you are in San Mateo. . . I'm just over here in Oakley (think Antioch and go a bit further east), and there are a few others close by as well. . . Perhaps a meet could be arranged? Quote Link to comment Share on other sites More sharing options...
idosubaru Posted December 21, 2004 Share Posted December 21, 2004 I AM A REAL BONIFIED FREAKING DAREDEVIL MANIAC....call the FBI cause this crazy freak changes his oil and DOES NOT fill the filter up with oil. i am one crazy mofo because i never have. i have a 206,000 mile XT6 that runs fat, has perfect compression all the way around and is likely to be around for awhile. and that's with the abuse i've thrown at it over the years. i've also had 2 other XT6's with 198,000 and 196,000. if i would have put oil on the frame rails maybe they wouldn't have rusted so bad i had to part them out. tell them to never buy certain year nissan maxima's and other cars where the oil filter FACES DOWN...OH MY FREAKING rump roast CHEEKS...they wouldn't be able to prefill their oil filters...AH!!!!! and don't give them word that the transmission fluid lines don't stay pressurized after shut down either.....i'd hate for them to get nervous about that....they could push the car down a hill, getting the wheels and trans pump turning which might pre circulate some fluid through the lines...after priming the motor of course. sorry it's late and i find this very funny. Quote Link to comment Share on other sites More sharing options...
Setright Posted December 21, 2004 Author Share Posted December 21, 2004 Lol! Quote Link to comment Share on other sites More sharing options...
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