04 Subaru WRX STI *Help*

[Vspec]

Ok, So I just picked up a REALLY REALLY clean 2004 Subaru WRX STI and I'm really happy with it. Per my crazy-self I plan to do a full over on it and make sure its in 100% running condition.

Already ordered Auto-RX for the engine, plan to do all 3 Diffs and the transmission as well. I don't know exactly what the diffs or transmission call for yet, but I'll go with Specialty Formulations for all three, and the transmission.

I'm currently running Mobil 1 Extended Performance 5w30 with VSOT in it to thicken it some because its summer and its a turbo car. When the Auto-Rx comes i'm going to dump the 5w30 switch to a (5w30, or 10w30?) oil and auto-Rx the engine. Then go to Red-line (5w30 or 10w30?) Oil. The engine specs 5w30, but I could always add some VSOT to it.

Opinions?

 

[sxg6]

how many miles on it? any maint records?

 

[carock]

Why Auto-RX on such a new car?

 

[Weasel]

No need to add VSOT to the Redline. It has a very solid add pack and high HTHS viscosity.

 

[black thunder]

i thought the diffs on these already had Synthetic Gear Lube......i'd just drain and refill

 

[bfg9k]

More than one BITOG'er has reported leaks with the Redline oils on Subarus. On my '98 Legacy the Redline power steering fluid made the ps reservoir leak like a sieve. The leaks stopped when I replaced the Redline with Royal Purple synthetic ATF. I'd just make sure to keep an eye on your seals and diffs when giving the Redline a try. I have the RP Maxgear gear oil in the front & rear diffs on my Subaru, with no leaks.

 

[SilverGGA]

How many miles? I don't see a need for Auto-RX unless the car has been neglected. Seems like the previous owner took good care of it from what you say.

The trans and rear diff call for GL-5 75w-90. SF MTL-R will do great. The STi has a mechanical rear diff and there is a special LSD oil from Subaru for it, if you want to use it instead. I use SF MTL-R in my WRX transmission and Redline 75w90 in the rear diff, which is different from your STi.

Make sure you use the Subaru brand coolant, as there is no 100% equivalent OTC Prestone etc. The all-make ones might work, but why experiment when the correct solution is available, in my opinion.

Subaru also specs a "coolant conditioner" and should supposedly be added every coolant change. It is sort of a stop-leak type product manufactured by a company named Holt in England. It was made to help with the head gasket leak in the older 2.5RS engines. But the service document says use it in all Subaru vehicles. I personally don't use it though because I don't think it's good for my WRX especially when our engines don't have the same problems the old 2.5RS did.

Redline 5w30 or 10w30 are all good. Mobil 5w30 or 10w30 EP or regular. Even German Castrol 0w-30. Monitor your oil level a bit as turbo Subarus consume a little bit of oil. Some brands burns a bit more and some brands less from people's experience. I personally use the now discontinued Mobil 1 Extended Performance 10w40 and will try GC afterwards.

Spec is 5w30/10w-30/10w-40 depending on ambient temperature. My preference is a bit thicker towards 10w-40 since I live in Northern California.

There are many STi owners in this forum and they can probably fill you in on STi specific stuff. And remember to give a thumbs-up to your fellow WRX/STi drivers you meet on the road!

 

[VaderSS]

I bought a 2000 Miata with 54k on it. It had a rough idle, so I ran 4 tanks of FP60 though it, with only a little change. I also cleaned out the intake, which was filty, with Amsoil Power Foam. Again, just a little change. I then ran AutoRx for 2200 miles. No real change, until I put the Castrol GTX rinse oil in. Within 100 miles, the engine was idling much smoother.

This engine has solid lifters, so the lifters have nothing to do with it, in this case. The only thing I can think to attribute the new smoothness is to cleaned ring packs.

I also feel that AutoRx is of great value at any age, especially when just past break-in, as it gets all of the casting/break-in trash out of the engine safely.

 

[sprintman]

Yes RX it. I use Red Line oils in my Outback not a sign of a leak. I'd Red Line 10W40 in the engine in summer fwiw...s

 

[Vspec]

I have records of prior ownership. However I still like to start with a clean slate for my ownership of a vehicle, so I auto-rx every vehicle I aquire, cheap insurance.

Anything else anyone can recommend?

Oh also the car has 44,000 miles.

Im going to replace the...

PCV Valve
Fuel Filter
Air Element
In-Cabin Micro Filter
Start a Techron regiment.
Replace all brake pads
Replace all fluids with full synthetics (PS, Clutch, Brake Fluids. Also replace coolant at Subaru dealership as there coolant apparently is different to anything I can acquire OTC.
Spark Plugs (Denso Iridiums)

Anything anyone can think I should replace? Thanks.

[ May 16, 2006, 06:52 PM: Message edited by: Vspec ]

 

[sxg6]

how come denso iridium plugs? every turbo ive come across has run best on copper plugs. although on a scooby theyre probably hard to change, so thats an advantage of iridiums

 

[Vspec]

I've never heard that in my life, every turbo car I've encountered has run Iridium Plugs.

Probably 5-10 SR20DET 240sx owners.

They all say that the Iridium doesn't degrade with the heat like other metals can.

 

[SilverGGA]

You can just buy the Subaru coolant from the dealership and replace it yourself. They sell it in gallon bottles.

I would just use the stock platinum spark plugs if this were my car. If you want to use Denso, go check at i-club.com and nasioc.com and make sure others have used it and have no problem before using it in your car. There is no significant performance benefit from spark plugs anyway. The stock ones are NGK platinum which is of high quality.

You are replacing more than you need for a 44k mile car, but if doing so makes you feel better, then it's fine. I think the plugs aren't due until 60k.

 

[Vspec]

I agree and understand what your saying. However the iridum are longer-lasting plugs and replacing them on the boxter engine is a complete hassle. So done once, done right, ya know?

Sure im putting probably alot of time and extra money into a relativly low-mileage STI however not knowing its previous running conditions, how the previous owner drove it, and understanding the nature of the vehicle I'd rather know its 100% then not know.