vulnax999

iTrader: (7)

Why is this necessary? I doubt my ( non Subaru ) garage do this!

The sensor removal / crank engine I mean, not the oil change!

Is it to make sure oil is all over the engine internals and circulating before the engine catches - i.e. the crank sensor removal stops it firing? There should be enough of a film and pockets of old oil in the engine after draining to still be lubed. Else it would be necessary every time you stopped the car for a few hours! As the oil filter is primed / half full, the oil pump will very quickly be on the job of pumping oil around...

Or are Scoobies that particular ?


Neil

[Edited by vulnax999 - 7/4/2003 6:18:49 PM]

MickeyWRX

Is there one for my MY95 Import WRX got the oil and filter just need to know how to do it coz i heard something about a crank sensor and removing an umdertray to get access to the filter?

pelase help!

dhorwich

Just make sure you drain old oil remove old oil filter, half fill the new oil filter then fit to car, replace sump plug and fill oil, make sure you leave it a while to settle properly... THEN BEFORE you do anything else, once the level is ok remove the connector on the crank position sensor which is just under the alternator (easy to get to on my MY95 WRX) then crank the engine over until the engine oil/pressure light goes out..!!

Job done, dont know about removing under tray as mine was easy to get to (oil filter).

Dan

S.B.

You need to change garages if there not changing your oil!!!!!

APIDavid

iTrader: (4)

Hmmmm, A few thoughts again !!

Dhorwich, You need to fill the filter twice, not half, as the first fill soaks into the material and the second fill acts like a small sump and is the reservoir for the filter system.

It is VERY INPORTANT to crank the engine with the ignition disconnected and preferably the plugs out, to take the load off the crank in a 'dry' situation. Starting the engine immediately from a change is a very bad idea especially on a Subaru that seems much more susceptible to crank problems than most engines.

Vulnax 999 your quote 'Else it would be necessary every time you stopped the car for a few hours! ' You are forgetting that when you drain the oil the pick up pipe is also drained and fills with air which need to be replaced with oil before the pump can create any volume let alone any pressure. Oil also has to circulate everywhere once cranked to meet a resistance so that pressure can build up.

just parking the car for a few hours doesn't expose the pick up pipe to air and thus the system remains primed. Not the same thing at all.

All been said before, but worth repeating for the few newbies that have missed it.

David API Engines

MickeyWRX

ok thanks for the usefull information but could you enlighten a few areas

*what is the connector on the crank position sensor and what does it look like - easy to find?

*cranking the engine?

do you have to have the ingnition on standby when doing this?

sorry for being a dimbass but i gotta know this before i do anything!

cheers

greasemonkey

Hmmm, tell that to the guy whose big end picked up the other week, after he skipped this step! Maybe you'll be alright if you just fire her straight up, but is it really worth a screwed crank and bearing shells just to find out?

There would indeed be film, and pockets. However, there's also enough anecdotal evidence to suggest that film and pockets alone sometimes aren't enough with a Subaru. Presumably the flat four engine design is a factor.

greasemonkey

Mickey, don't worry about the dumbass thing. The fact that you're bothering to ask first means you're not one!

The crank position sensor is easy to find. It's underneath the alternator, immediately behind the timing belt cover. If you look at the timing marks on the belt cover (the 30-20-10 graduations), behind them you'll see a plastic gadget with a plug and two wires sticking out of it.

Press the little clip on the side of the plug in, and pull it off the sensor.

Once you've got it disconnected, dry-crank the engine. That basically means trying to start it. The engine will turn over on the starter motor, but because the sensor's unplugged, it won't fire. Keep it turning over on the starter until the oil pressure light on the dash (the red oilcan) goes out. Should be somewhere between 10 and 20 seconds, but don't worry if it's a bit quicker or longer than those.

Once the light's out, stop cranking, reconnect the sensor and start the engine!

Bob Rawle

Regarding filling the filter it can take up to 20 mins before the filter material has soaked through and you have a full filter, you need to keep topping up during this period as well, as APIdavid says this is a very important point.

bob

scoobystityper

MAKE SURE YOU REPLACE THE SUMP PLUG WASHER FOR A NEW ONE

dhorwich

Bob,

I did find that when filling my new oil filter it took a fair bit of oil/time to get it half full and it just kept soaking in i filled it over about a 30 min period.

Dan

maniac morgan

read so much on oil in the last few weeks and every time a new thread comes up i learn somthing new, its very refreshing the freeness that our resident experts share their vast relm of knowlege.

keep it up guys.

morgan.

maniac morgan

doing a change on sat meself

whats the lowdown on engine flush, i know it has been forwned upon in the past as it can gather in pockets etc but is it worse to have old dirty oil in engine ? whats the best trade off ?


morgan.

greasemonkey

Shouldn't be necessary. If you're changing the oil as regularly as you should, the old stuff won't be that "dirty" to start with, and in any case, if you warm the engine first and give it plenty of time for all the old to drain, there's hardly going to be any left.

johnfelstead

yep, agree with Bob and Dvaid, dont half fill the oil filter, fill it to the top and keep topping it up until it wont take any more oil. It's time consuming but its the only way to ensure the filter is properly primed.

johnfelstead

you are never going to completely empty the oil system when you do a change (especially if you have an oil cooler installed), this is why changing the oil more regularly than 7500 miles intervals will give better protection.

APIDavid

iTrader: (4)

If you've got an oil cooler installed I recommend that you remove it and flush it and then refill it and replace it. It'll never drain in situ and thus you'll always have about a litre of dirty oil left in the system. Nightmare things coolers as they are usually in the supply line from the pump to the engine and therefore it takes even longer for the oil to get around and pressurise. If you're not doing regular track days take the damn thing off.

David API Engines

PS Controversial I know but I see to many busted engines, because of silly gizmos that aren't actually having any beneficial effect being used on a road car.

pat

It's amazing how many places, including Subaru "specialists" just don't understand the importance of establishing good oil pressure before firing. The design of the flat four engine means that there isn't much room for the bearings, there's nine journals in the short space from the front to the back of the engine!

If you compare a flat four to an inline four, you have almost twice as much space for bearings in an inline design, hence the bearings tend to be a bit bigger and thus a bit more resilient. Just think about the fact that a Pinto has bearings that are 25% bigger than an EJ20.

A hydrodynamic bearing relies on the oil being present. Under normal operation the two parts of the bearing (the journal and the shells) are kept apart by the oil film, and never the twain shall meet. Take away the oil and the shells soon introduce themselves to the journals, then it's only a matter of time before it lets go.

Over the weekend we came up with a great idea that will help save engines, even if your dealer is a complete fsckwit and tries to fire the engine before establishing oil pressure. Watch this space

Cheers,

Pat.

johnfelstead

I agree David.

Pat, it would be dead easy to knock up a system to not allow the engine to fire until you get oil presure. But you know that.

MickeyWRX

cheers for the useful help guys especially Greasemonkey - good answer lots of detail just the way i like - i will go and look for the sensor now!

cheers

mega_stream

I've done just 3k in my RA in the last 6 months, was planning on doing the oil change in the next 500 miles, just wondered is changing the oil from a time perspective really needed?

I'm on about evey 6 months here, not into years

Also, same apply's for my spark plugs, cars running fine, done 8.5k miles, do I need to bother changing the plugs?

APIDavid

iTrader: (4)

Mega Stream, Chnage the oil every 3000 miles no matter what. One thing I've learnt over the last 20 years importaing Japanese engines is that they like nice fresh oil. Japanese engines are built to closer tolerances than European ones [ in general] and the black stuff in the oil when it gets dirty is carbon - hardest substance known to man - no need to say mre really is there?

Plus last forever these days and I'd probably leave mine for 40,000 miles [60,000 km's] There's no real drop off in performance because of the improvement in the quality of the electrodfe used.

David API Engines

Scooby96

Would someone be kind enough to post a reply confirming exactly what needs to be done if doing an oil change as theres snippets of info over several threads and some contradict so its got me confused! Much appreciated in advance

greasemonkey

Lol! It's all in this thread!

Something like this then:

1) Warm engine
2) Drain old oil from sump
3) Remove old filter
4) Pre-fill new filter with fresh oil. Fill and keep filling until it won't take anymore.
5) Apply new filter
6) Apply new washer to sump plug and tighten
7) Fill engine oil filler to mid-way between two holes on the dipstick
8) Disconnect crank sensor
9) (Preferably) remove spark plugs
10) Dry crank engine at least until oil pressure light extinguishes - ideally for 20 seconds or so more.
11) Refit spark plugs
12) Refit crank sensor plug
13) Start engine, leave to idle for a good minute or so before driving for oil pressure to stabilise
14) Check sump plug and filter seal for adequate tightness/leaks
15) Go for slow drive until engine fully warmed
16) Top engine oil to upper hole
17) Check sump plug and filter seal for adequate tightness/leaks

Did I miss anything?

Had edited this, but then decided not to, for reasons expressed below...!

[Edited by greasemonkey - 12/07/2003 00:04:31]

Scooby96

nice one, cheers - last request greasemonkey can you take a look at my thread in the projects area re dash replacement as I so want to ditch the standard MY93 WRX dash - its fecking orrible

mega_stream

Thanks for the info David

I wasn't planning on missing the oil change , just wondered about the time thing really.

APIDavid

iTrader: (4)

greasemonkey, You are the man !!! All Subaru owners from all over the world will cherish your words of wisdom for ever.

Seriously, It's the first time I've seen it written down right by anybody other than my staff. There should be a faqs thread that this stuff is permanently on display so that we don't have to keep repeating it every other day.

Mods, Where are you when we need you ?

David API Engines

johnfelstead

You havent been here long have you David

greasemonkey

<blush!> Cheers David, but not really fair to claim all of them as my words, all I've done is put the collective wisdom in one post.

Good point, seems to have come up loads in the last couple of weeks alone. Must be the good weather prompting a lot of DIY servicing! This is the sort of thing that would save so many an expensive bit of grief, would be handy if the list (if not the entire thread) could be kept somewhere it'll be seen by those who need it.

Serious point though, I wonder how many main dealers take the time to do it properly? If I was IM I'd be mandating something like the above as policy, and making damn sure it was adhered to. The money it would save in warranty claims should make the extra time worthwhile...

Scooby96 - will have a look mate but not sure how much I'll be able to help. Got a pretty good working knowledge of the post-facelift dash, but know virtually nothing about the old one

Leslie

As well as that good thread from Greasemonkey, the advice from David is also very good. An engine like this one deserves the extra care and it is well worth changing the oil at 3000 miles. Also it stays clean and won't need flushing. For your interest, I checked my NGK plugs at 12,000 miles the other day and the points gap was within one thou of where I had set them originally. They are advertised as good for 45K miles anyway but that confirmed it to my mind.

Les