I have a 95 import wrx with 2.5 sti bottom end conversion, td05/16g, sim-tek ecu, running 280bhp 310, forged pistons, yellow injectors etc etc.
last weekend it had a complete oil change with filter etc i have done roughly 160miles and the oil nedds topping up already, any advice on wat the hell could be going on?
it has always drank oil for some reason but now i'm getting a bid pissed off, any advice peeps would be welcomed.

 

You're not putting Treacle oil in are you? By that I mean 50 or 60?

Or too thin, like 5W?

Put 10W-40 in and see if it improves things.

Do you have a leak anywhere?

 

no leaks mate, i was usin 10-40 b4 the change and it was doing same , so a few people said 2 try a 5-50 fully synthetic.

 

How much are you having to top up?

 

as i said gave it a service last sunday so that took just under 5litres, then put another 1.5 roughly in 2day

 

some 2.5s use oil.
Acceptable level supposedly 1 liter per 1000 miles
Forged engines also looser especialy when cold and oil gets past the pistons.
So they are known to drink it.
That useage seems excessive however and not a good sign

Silkoline 10w50 pro S is a good oil to use

 

So wat r the signs? Car runs fine other than this. 4 got 2 mention the turbo needs replacin as it smokes on boost, could this b the reason 4 usin alot of oil?

 

You may want to cut down on the text speak ...... you are allowed as many characters as you need to make sense on here

 

Bloomin eck, thats RX8 territory

 

Yeh cheers fella that cocky comment really helps.....

 

You want advice or not mate? You asked for help remember!

 

Advice is great but not sure how smartass comments counts as advice, so wats ur advice then?

 

Forged pistons may be a little small for the bores.

 

Cheers sticky, how would I find that out? I don't wana pay a huge mechanics bill, I'm only a little handy at doin basics, pretty new 2 the Subaru world lol

 

If you know RX8's they are designed to use oil with oil being injected onto seals and rotor tips and 1L per 1000 miles is an acceptable ammount. On a normal engine 1L per 1000 miles is excessive. My 2005 Sti when running 400bhp never needing topped up in all the 5 years I have owned it. I am now having a fully forged engine built and if I saw the kind of oil usage you are talking about I would be sending it back.

So you see my response to the person stating that 1L per 1000 miles was valid as the information to you was misleading.

Probable causes for your oil usage are that the pistons have not been matched to the bore as no two forged pistons are identical. Each piston should be individually measured and the bore honed to suit.

Another possible cause is that when honing the liners a belly has been honed into them again letting oil passed the rings.

Or possibly on one of your pistons the gudgeon pin has been a little slack thereforeallowing the piston to wear the bore oval again letting oil passed the rings.

Yet another possibility is that the oil seal is goosed in your turbo allowing oil to leak through

Another thing is to check that you do not have a blocked breather as this could also cause increased crankcase pressure forcing oil up passed the rings


I wont take your cheeky comment to heart but as only a newbe perhaps you should not be so aggressive in your posting style untill you are a little more established

 

Cheers gmac good advice 4 me 2 look in2, as 4 my cheeky comment it was aimed at the fella talkin about my text wordin lol
I'm sure u can appreciate that it is a little annoying everytime some1 posts a reply I get an email, and wen I get an email I assume I have useful info on my problem and not banta about my wordin.
Anyways wats the best way 4me 2 check all ur examples mate, is it a costly process if I get a pro 2 look???

 

Aye no bother.

As far as breathers, the easiest way is just to talke them off and clean them through, as far as trying to see about the bores, prob the easiest way is to take it to your local specialist and have them do a compression / leakdown test which will tell them if the rings are sealing properly.
And as for the turbo, do you have any blue smoke on the over run when you lift off?

 

the smoke looks greyish on boost

 

Like I said .... try speaking without text speak

 

I had a forged 2.5 in a Classic, it also used oil, around half a litre per 1000 miles, depending on how hard it was driven. It is acceptable use.

The fact your oil seals are leaking on your turbo is clouding the issue of oil consumption, you need to get that fixed & then check the consumption over a period of a week (if you use the car daily), making sure you dip the oil daily & when the engine is stone cold so the readings aren't distorted by heat. Hope that helps.

Typing in "txt-spk" is annoying and hard to read. This isn't a mobile phone text message, its an internet forum, and not a "krooze-forum". Please feel free to use the correct spelling & punctuation in your posts ("lol" is not punctuation by the way).

 

I'm now learning that ulot love a bit of banter so from now on I will try and use proper punctuation. Thanks for the advice L.O.L ;0)

 

On a 2.5 a RETURN TO SUMP catch can is a very good idea.
Hope this helps
Steve

(Also it is a good idea to monitor oil temps - and perhaps run an oil cooler
So an oil temp guage is a good idea, just to see what is going on)

 

Surely the fact the turbo's blowing oil is not helping? Get it sorted, and see what oil it uses then. Until you do this, it's impossible to determine the amount the engines using.
Are your breathers still plumbed into your intake? If you're running high boost, it'll be drawing oil through/burning it off.
The above plus the forged build tendency to use a little oil may all be adding up.

Mit