We've seen a few instances of bearing failures where the common denominator seemed to be that an oil change had recently been carried out. It's not like they were all grenading the day after a service, but it was certainly enough to count as a trend.

There are very simple reasons why the EJ20 design (and that of horizontally opposed engines in general) is critical as far as lubrication is concerned, and thus it's not hard to imagine the circumstances under which a transient loss of oil film in the bearings could lead to bigger problems shortly afterwards.

It was this that started the discussions off, eventually leading to the collective wisdom that's been expressed in threads like this one.

 

Just did an oil change and put in 4.75 litres in my JDM STI-7 .....is this too much ? I heard the norm was 4.5 - 4.8 litres ?


Anychance this can damage my engine if it is too much ?

Cheers,
Ray

[Edited by Razor2001 - 7/29/2003 12:20:09 PM]

 

What does the dipstick say? If it's too high, you could always loosen the sump plug and slowly drain a little out, but 250ml shouldn't be enough to do any mischief. Still, if it puts your mind at rest...

 

So, I decided that the engine in my (new to me) MY02 WRX needed some new oil and followed the recommendations here. However, once started again the CEL was lit up, presumably something to do with the cranking with the CPS disconnected.

I thought I'd check the ECU error code and, following the information hereabouts I went looking for the two pairs of connectors, one green, one black, which apparently live under the steering column. However, my car has a green pair, a single black and a single white connector. (At least as far as I've found so far.)

So, I guess the ECU in this car is different somehow. ANy suggestions of how to get rid of the sodding CEL light other than going to a dealer with folding green stuff?

Tim

 

remove the negative battery cable for 30mins to 1hour... but remember stereo codes e.t.c

Dan

 

Actually, I left it disconnected for a couple of hours, to no avail. So I went out for a drive to see if the ECU was operating in limp home more or something. After I stopped and restarted the engine the light went off...Curious...

Tim

 

If the light's gone off, it'll mean that the ECU is now satisfied the sensor's reading normally. Thus, no need to worry, and no need to worry about clearing the stored DTC until it next goes near a Select Monitor/DeltaDash etc.

Looks like the Denso ECU's (and whatever's on the Legacy too) cross-check the cam and crank sensors when turning. Shame really as you can remove the CPS on the classic Imprezas and turn the engine over without causing a DTC...

 

Yeah. I guess it means the oil change procedure should say really remove the plugs and leave the CPS alone on a new age impreza.

 

The reason the crank sensor removal is suggested is that it prevents spark and fuelling. If you're going to be turning the engine over with the plugs out, it's probably better to not have atomised fuel/air mixture shooting out sides of the engine.

Thus, on balance I'd still suggest disconnecting the CPS, even if you remove the plugs.

It may be that with the Denso cars, disconnecting both the crank and cam sensors will prevent a CEL. Anyone with a new age car willing to test this theory?

 

I was wondering about doing it. I was looking at the engine this morning and there seems to be a sensor on the top-front of the left hand cylinder head. Is that the cam position sensor?

I might wimp out though, and leave it until the next oil change...:-)

 

On 99/00 the crank position sensor unplug trick leaves a historical fault code in the ECU.

The 2002 service manuals also do not mention unplugging any sensors or spark plugs, but I still do it.

I note that number 3 crank journal has a different design to withstand thrust forces. Wonder if this is anything to do with fabled number 3 failures, although it seems they are by no means not all number 3.

[Edited by john banks - 8/30/2003 1:20:46 PM]

 

Dave - interested in your comments, just orderred my new WRX with Pro Drive Engine pack - fitted from new, I'll run it in really carefully obviously and note your comments re semi synthetic for first 10k - then fully snthetic. I'll be doing lots of motorway driving as I do 35k/year and should have really bought a comfortable auto with cruise - but what the hell! Will I still need to change oil as regularly and do the dealers generally follow the correct procedure for oil type as you suggest and changes or just fill em up and fire em up!?

Cheers, macka

 

WRT dealer oil change procedure Macka, it's best to simply ask in advance how they change the oil. If the service monkey gives you a blank look and starts to explain how "We take de oil out of de car, and put de new stuff in, like", you can assume they just change it and fire her up, and thus you may choose to have it serviced elsewhere, or insist to the service manager that it's done properly. Many Scoob dealers do as a matter of course, so it shouldn't be too much to ask.

As far as oil change frequency is concerned, 10,000 miles is far longer than ideal for one fill of oil, given the tight tolerances and high specific output of the EJ20 turbo engine.

If the vast majority of your driving involves sensible motorway cruising, you could extend the oil change to 5K miles, so you do one in between each service. If you spend a lot of time on the backroads however, every 3300 is better.

Having said all that however, if your plan is to keep the car a year or two then part-ex it back through the dealer network, it may prove more cost-effective (if less mechanically sympathetic) to simply stick to the recognised service intervals.

 

Macka, Just off to Japan again so l'll be brief. I would do my own oil changes between the recognised ones. Split the interval equally in half so that you do one exactly halfway between the Subaru recognised. I'm assuming that you are competent to do the work as suggested by me a page or 2 back. Just make sure to use genuine Subaru oil filters so they're non the wiser.

David API

 

I live in Australia and have a 02 STi. I think all Australian Impreza's are delivered with a Brant(Alarm - Immobiliser). Before the engine can be started a 4 digit pin code has to be entered, otherwise the engine will just turn over and never fire.
Would this be sufficient to satisfy the(Disconnect Sensor,remove spark plug)recommendation?
Thanks in advance
Ken

 

G'day Ken, Good idea by the sound of things. David API

 

Just been reading through this thread and just wanted to say thanks for the excellent advice. I’m planning on doing some of the basic servicing myself once the warranty expires in the coming months but I just have one question, what would you recommend for the oil change intervals for my IMPREZA SPORT MY99.

The car gets/enjoys a good hard drive but is mainly used in short journeys, also gets some long motorways journeys once a month or so, if that makes any difference.

Thanks in advance, Lee


[Edited by phatso - 10/10/2003 5:21:14 PM]

 

Excellent thread, i'll be changing my oil in the next 500 miles or so glad i found out about disconnecting the crank sensor before i did.
I only have one question, where exactly is this crank sensor ??

 

Lol! If you know it's an excellent thread, you presumably read it? If you did, you'll know that the location of the crank position sensor is described on page 1!

 

Errrr guys, i did an oil change and didnt follow this procedure of disconnecting the crank sensor. Have i caused damage????

 

That's an impossible question to answer without stripping the engine down and examining it.

At end of day this is not worth worrying about. What's done is done, and your engine is probably still fine. If it isn't, you'll find out soon enough.

 

LOL oh yeah sorry mate, found it now

 

Green, I think what David was getting at is that removing the spark plugs is the best way of doing it (as it takes the compression out and completely relieves the load on the bearings), but that if you don't fancy going to those lengths, the crank sensor option gets you most of the way there

Regarding Ragnarock's comment, on first thought you have a damn good point.

However, on second thought, if the crank sensor's off, not only will the spark signal not be sent, the injectors won't trigger either (ECU needs to see the crank rotating at 250rpm before it'll start fuelling and sparking).

This isn't a bad thing, as not only will you save a thimbleful of petrol (), you also won't have an atomised fuel/air mix shooting out of the spark plug holes while you're cranking her over.

Thus, for the time being at least, the "FAQ" (such as it is!) will continue to recommend removing both the plugs and the sensor connection

[Edited by greasemonkey - 7/12/2003 3:35:20 PM]

 

Excellent thread. Just one problem when I did it though, when cranking the engine - with the sensor disconnected - the oil light on the dash didn't go out as i had expected it to. Had nearly 4 litres of oil in the engine. Tried starting the engine about 4 times for a duration of maybe 10-15 seconds at a time.

Did I crank it long enough?

The car is a newage MY01

Thanks
Mark.

 

Last two replies here:

http://bbs.scoobynet.co.uk/showthread.php?t=333883

 

Mark, as Jiggers says, on some cars, the oil light just doesn't extinguish at cranking speed. Provided you filled the filter before fitting it, the 30-50-odd seconds you gave it on the starter should be more than adequate.

FWIW (and crossing over onto the other thread), I normally do exactly what you did - a number of 10-15 second bursts with gaps in between rather than keeping the starter going for ages.

 

Yeah, I did fill it. Thanks for your post - I'm reassured I haven't caused any damage (other than the 4 litres of old oil that poured onto my driveway because my container wasn't deep enough ). Lesson learned.

Mark.

 

This thread has been full of excellent advice from experienced people such as DavidAPI and Greasemonkey. Regardless of the workshop manual advice on oil changes there are very good reasons for that good advice. The narrow bearing journals on the EJ20 engine mean that bearing pressures per unit area will be high and therefore oil supply has to be right for adequate protection. The cranking before start up is necessary to ensure that the engine oilways are all fully primed before the engine fires up. The oilways will drain down during an oilchange and it takes time for the oil filter oilways to fill up again fully even though you might have filled the filter fully allowing the oil to soak into the element.

It is true that bearing failures have often been experienced after an oilchange as they say. If you wish to be cleverer and continue to do oil changes without those sensible precautions, thats up to you. Don't be shy about telling us if you do experience the dreaded rattle shortly afterwards though!

Les

 

BTTT for a jolly worthwhile thread,


We REALLY should have a FAQ section ...

 

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?


Greetings from a place far far away... I am from Christmas Island, Western Australia and I think I am the only guy from this part of the world that is a member
Anyways I have a question that needs to be answered *looks at greasemonkey and/or any other informative help out there to help a poor brudda out*

I gots a MY99 V5 Sti Type R and I read somewhere on this post that on a MY99/00, removal of the CPS would give the ecu a error of some sort...? Is this the case?
It has carbon build up in less than 2 months! Would anyone know why this carbon build up happened quickly? Could it have something to do with the dusty conditions we have here + the humidity? Or worse???

I'm kinda worried about this procedure (but very good info ppls, btw, very informative!) if something f**ks up, I am in the deep end. On Christmas Island, we do not have access to top mechs and workshops and the likes. So your help (and other's) is muchly appreciated! I am only going to replace the oil until I get some good premo Redline engine oil, Light weight shockproof gearbox and diff oil, water wetter and SI-1 Complete fuel system & injector cleaner, by next week. Would all this premo goods help reduce detonation/pinging? We have 95ROn fuel over here and I am afraid the cause of the premature death of my engine would be a factor of one of those things... or *shudder* all of them combined!

1001 thank yous in advanced!