Lady T

Hey

I recently did an oil change, now after driving the car, everytime I stop at traffic lights etc...the oil pressure keeps falling below 2. This causes the defi warning light and beeping to come on. From my understanding it shouldn't drop below 2, is this correct??

Also how do I make the problem go away?? A good hard drive maybe??

Please advise

banny sti

iTrader: (68)

I would check the oil level as it should have no reason to drop below 2, especially if it did not do this before the oil change. Normal idle oil pressure should be abour 3 bar.

Banny

Lady T

Il check it today before I take it for a rip.

Its not dropped like that before...

Thanks Banny!

RAPID STI

iTrader: (4)

Taking it for a 'good hard drive' will lower the pressure even more as the oil is hotter.

My oil pressure used to be 1.5 bar on hot idol when I used a thin crappy oil. Since using an ester synthetic 15w-50 it sits at 2 bar hot idol. After a few laps of Oulten Park it drops to just above 1 bar on idol.

IIRC anything above 1 bar is still safe according to Subaru.

jasonius

iTrader: (1)

Are the engine revs also dropping, as this would cause a dip in oil pressure..?

Mine does this every now and then (12-18mts) does this when pulling up at lights etc, sometimes almost stalling and very briefly setting off my defi alarm, which I have set at ~2.5bar.

In my case it's cured by cleaning the idle speed control valve with carb/brake cleaner. Take a look here:
Cleaning And Reattaching The IACV (Idle Air Control Valve) - NASIOC

Do get a spare 'o' ring gasket (part #22659AA120 ~£5 from main dealer), as recommended in the above link and I also replaced the very soft screws with some decent ones (M5x20mm with flat washer and spring washer as originals). I found a VERY useful company that sells all sizes/styles of stainless bolts/screws etc in any quantity from x1 at reasonable cost and cheap P&P:
Stagonset Stainless Nuts and Bolts, Screws and Fasteners
Most other companies only supply 'bulk' numbers, most of which you'll end up not using..!

Anyhow, the hardest part of doing this is undoing the soft OE screws, especially if they've never been undone from the factory..! Use a big flat bladed screwdriver and give it a little tap on the end with a smallish hammer before undoing. Even then the screw heads may strip, so be careful.

Once it's off, flush it out with cleaner, then reconnect electrical connector. Place solenoid upside down on a decent sized rag and fill with cleaner, then turn ignition key to on (ie dash lights up) NOT STARTING THE ENGINE and off several times. You may see the cleaner splash up a little as the valve opens, that's what you need to happen. Then flush out again, replace ISCV housing using new gasket and screws if possible.

I now make this part of my annual service schedule.

A couple of points, with regards to the gasket. If you remove ISCV and the gasket has stretched, you will have a real problem if you don't have a replacement to hand. Failure to seal the ISCV properly will allow coolant into the combustion chambers, resulting in dense white smoke out of exhaust..! A little trick that I used the first time, when the gasket wasn't too bad, was to put it in the freezer for 20mins or so. This shrunk it enough to allow re-fitment..
Finally, the dealer description for that part number is 'Gasket-Air cont.' which can be a bit confusing. Rest assured it is correct..

If your engine revs are dropping and therefore causing the oil pressure to also momentarily drop, then I can almost guarantee that doing the above will solve it. Unless the ISCV is shagged (most unlikely), in which case cleaning it may well fubar completely. Either way, clean it first and take it from there, as they're £250 iirc..!

Let us know how it goes..

Lady T

Hey thank you so much for the info.
I will definately try that and keep you posted! Thank you

harvey

iTrader: (48)

The type of oil and even the type of filter can alter oil pressure. Did these change from what was used previously???
As above, is the idle speed lower for some reason?
How does the pressure compare with previous above 2k or 2.5 k rpm?

Juice

^^^ oil used previously was 10w-50 silkolene pro s

however when speaking to poie oilz they advised using 5w-40 as this would protect the engine more as the car is used on short journeys and not used on track
the oil pressure use to sit above 2bar before with the 10w - 50 ......now when the cars had a good hiding it hovers in the middle between 1 and 2 stabilising at 1.6/1.8bar pressure

filter was also supplied from opie

i dont recall seeing the idle speed lower tho, but will double check

The Rig

iTrader: (13)

Low oil pressure at idle is a sign of big ends on the way out also,not saying it is by any means, but its worth remembering,as has been said, a few other factors can cause your problem but just keep an ear out !

i use magnatec 10/40 and havent had any issues as yet (2.5 yrs) touches wood and keeps rabit foot in pocket

good luck bud

dynamix

iTrader: (3)

it's the 5/40 natts pee oil doing it

Turbotits

iTrader: (2)

Have to agree. Change it again using 10/50 and an o/e filter

dynamix

iTrader: (3)

I dont know why Opie continue to advise people to use that stuff....

jasonius

iTrader: (1)

But if the revs are dying when pulling up that would also cause pressure to drop.

So, lady T does the engine almost stall when pulling up at these said lights and then recover (ie oil pressure warning bleeps briefly)..?

harvey

iTrader: (48)

If you were using 10W- 50 and have switched to 5W-40 then you will see lower oil pressure and it will be more noticable, fully warmed at idle. I think that is what you are seeing.
There are also slight differences between different makes of oil filter. It matters little who supplied it. There is no excuse for using anything other than the genuine Subaru article. About £6.00.
Personally I would be running 10W-40 in that engine although Subaru say lighter oil is OK and I guess they know what they are doing.
I don't think it is a big problem but for peace of mind you may wish to run a thicker oil, 10W -40 or 10W- 50.

Juice

the car does not hesitate when pulling up, but the pressure just dips slightly. isit safe at 1.6bar?
apparently below 1 bar is when we should panic or am i wrong.?

The Rig

iTrader: (13)

1.6 bar is on the limit of being worried.

any knocking ?

whats the pressure like at idle when cold ?

whats the pressure like when crusing at 60 mph ?