Rotella T6 5w-40 @ 2.2k miles; 2005 Subaru Legacy 2.5L with mods

[ScottyB]

Thanks for your post. I'm very much of the same mind that this is early warning is a gift. I have been in touch with a few of the reputable tuners in my area (of which there are many in the Northeast) and exploring my options. It's shaping up to be a choice between a Spec RA block or the Stage 2 offerings that exist out there (along with an upgraded oil pump and other supporting mods). I know this is going to sound very silly but I have not been keeping track of knock. Learning to monitor the engine is something that's been on the to-do list that I've never gotten around to. I'll certainly push this to the top of the list now with whatever new engine I get.

Very cool to hear about your 2.5RS experience, sad to hear it was rear-ended. They remain beautiful cars (just saw one the other day). I'd love to get involved with rallycross someday - I did spend 5 days at Team O'Neil a few years ago.

i don't blame you at all - tuning is a black art to us outside of that craft and what little i do know from trying, and mildly succeeding to tune mine (on an opensource ROMraider tune) was how far down the rabbit hole you can get. the learning curve is more like a wall. even minor things can have ripple-effect consequences. one thing i did learn conclusively is - the stock Subaru tune is as bad as everyone says (even for the N/A cars) once you dig into it, and it was super disappointing to find out. for that reason, its the #1 point of reliability i'd address with your next engine, and i would definitely give it another chance considering the rarity of your Legacy wagon....those cars are the peak of that subaru era IMO. i would just caution to keep the power level conservative enough that the next point of failure won't be the gears in the tranny!

can't recommend rallycross enough, if you have a vehicle you don't mind getting scratched up a bit. its unbelievably fun and requires far less prep, in my opinion, than autocross to be at the pointy end of the field. as a bonus, rallycross fields tend to be smaller so you get more run time!

i didn't have the pretty generation that everyone knows - mine was an '05 with a lot of suspension goodies and an exhaust, but left otherwise mostly stock. autocrossed, tracked, rallycrossed, mountain roads, literally everything you could do, i put that car through.

 

[OVERKILL]

Ah, thank you. The car was throwing a P0172 (rich) code when I sent in the analysis. I looked into this and found the MAF was very dirty. I've since cleaned it up and the code has not returned.

Yeah, the flashpoint near 300F means that oil has a massive amount of fuel in it.

 

[Enlight]

Well I have a significant update! I was browsing Facebook Marketplace and found someone selling a never installed IAG Stage 2 TUFF short block. I paid what would amount to a 40% discount off what it MSRP's for, or about $300 more than a Spec RA block would cost from a dealer. I won't be able to take advantage of IAG's unique 2 year/24 month warranty, however, there is an IAG Gold Installer just 40 (Vinny Ten Racing) minutes from me that I will ask to do the engine assembly. Between them assembling the long block and consultation on supporting mods, I'm curious to see what kind of longevity I can expect out of this engine.

I'm also going out on a limb and plan on playing with a coolant pre-heater to mitigate start-up wear in this forged engine. These are used in colder climates up north (Canada) to ease starting an engine and also more prevalent in Europe to warm the cabin. I started a thread here to discuss it.

 

[Enlight]

i don't blame you at all - tuning is a black art to us outside of that craft and what little i do know from trying, and mildly succeeding to tune mine (on an opensource ROMraider tune) was how far down the rabbit hole you can get. the learning curve is more like a wall. even minor things can have ripple-effect consequences.

I definitely plan on keeping this wagon indefinitely and, at this point, am doubling down on it. I'm hoping one day I'll be able to give it the paint job it deserves. My first order of business will be to start data logging the engine when it is completed. I'm going to have to familiarize myself with Btssm/Accessport/other data logging solutions. I'm reading knock/fine knock learning is what I should first focus on, which makes sense.

Yeah, the flashpoint near 300F means that oil has a massive amount of fuel in it.

Yeah, I should have checked the MAF way earlier. I'm surprised the sensor fouled up that quickly since I last cleaned it, but that must be because of my oiling the filter which I now remember some people warning against. I'm sure this did nothing to help my bearing wear.

 

[OVERKILL]

I definitely plan on keeping this wagon indefinitely and, at this point, am doubling down on it. I'm hoping one day I'll be able to give it the paint job it deserves. My first order of business will be to start data logging the engine when it is completed. I'm going to have to familiarize myself with Btssm/Accessport/other data logging solutions. I'm reading knock/fine knock learning is what I should first focus on, which makes sense.


Yeah, I should have checked the MAF way earlier. I'm surprised the sensor fouled up that quickly since I last cleaned it, but that must be because of my oiling the filter which I now remember some people warning against. I'm sure this did nothing to help my bearing wear.

Check to see if Volant makes a dry filter (powercore) for your application. Otherwise, I'd suggest switching to a non-oiled filter.

 

[ScottyB]

Well I have a significant update! I was browsing Facebook Marketplace and found someone selling a never installed IAG Stage 2 TUFF short block. I paid what would amount to a 40% discount off what it MSRP's for, or about $300 more than a Spec RA block would cost from a dealer. I won't be able to take advantage of IAG's unique 2 year/24 month warranty, however, there is an IAG Gold Installer just 40 (Vinny Ten Racing) minutes from me that I will ask to do the engine assembly. Between them assembling the long block and consultation on supporting mods, I'm curious to see what kind of longevity I can expect out of this engine.

I'm also going out on a limb and plan on playing with a coolant pre-heater to mitigate start-up wear in this forged engine. These are used in colder climates up north (Canada) to ease starting an engine and also more prevalent in Europe to warm the cabin. I started a thread here to discuss it.

excellent news and it sounds to me like you really did jump on a deal. IAG is well regarded. great to hear you're keeping the wagon long term. given the overhead on that block's power capacity compared to what you'll probably be making, i would expect a LONG life out of that block with a good 5W-40. you're on the right track getting familiar with the knock metrics in the tuning solution, that's the killer.

when racing, i routinely raced in super dusty "talcum" dirt and got my air filter dirty enough i could shake the dust out of it and never had an issue, just replaced it on a "severe use" schedule. I would switch back to a dry filter for your application and just check it annually for replacement, i doubt it would cause any power loss.

 

[Vermess]

Nice ride, bud. Looks like you spent some cash, I'm going to give you a little bit of advice so your cash doesn't go to waste.

1. Whomever that tuner was who tuned your car based on the dyno sheet you posted, he should never tune another subaru.....ever... peak torque of 330 at 3300rpm at the wheels is about 420 at the crank. Consider yourself lucky you only have bad bearings and it didn't come apart and take out the heads.

2. If you have a oil cooler, throw it in the garbage as well as your oil pump. Replace both.

3. Take the plug out of the drivers side head, recirculate that coolant into the heater core return. Without that, the tune will NEVER be right. If the tune reads rich, cyl 4 will be pig rich. If the tune reads good, cyl 4 will still be rich and the other 3 cylinders will be lean.

4. Don't push that block beyond 450whp. Those weak sleeves won't be able to handle it.

5. Save those cases if you want to go nuts in the future. Find a shop that's familiar with Subaru, sleeve it, pin it, line hone it, rods, pistons, stock crank, 2250cc injectors and a 6262 will get you 1000whp.

 

[Enlight]

Thanks for the tips, @Vermess. Based on a proposal I got, the shop recommended upgrading to a 11mm oil pump, replacing the oil cooler, as well as the VVT solenoids and both intake camshaft sprockets. I'm not going to go with this shop that quoted me, but I plan on sending my heads to Head Games Motorworks (close to me) to refresh the heads and assembling them to the IAG short block myself. Do you agree that the VVT solenoids and intake camshaft sprockets should be replaced as well? I started up the car today and the rod (?) knock was audible at start up, then went away after 5 seconds once the oil circulated. The car has been sitting for about a month plus. The car already has the cylinder 4 coolant mod.

 

[Vermess]

Thanks for the tips, @Vermess. Based on a proposal I got, the shop recommended upgrading to a 11mm oil pump, replacing the oil cooler, as well as the VVT solenoids and both intake camshaft sprockets. I'm not going to go with this shop that quoted me, but I plan on sending my heads to Head Games Motorworks (close to me) to refresh the heads and assembling them to the IAG short block myself. Do you agree that the VVT solenoids and intake camshaft sprockets should be replaced as well? I started up the car today and the rod (?) knock was audible at start up, then went away after 5 seconds once the oil circulated. The car has been sitting for about a month plus. The car already has the cylinder 4 coolant mod.

Brother, before you jump in head first, entertain this for a bit. Take off a timing cover, make sure that it's not the timing tensioner.

Second, unplug the vvt solenoids and see if it does it.

I've had great luck with cleaning the intake sprockets. But with age, it's cheap insurance to replace both.

Are you familiar with assembling subie heads??? Them buckets aren't easy to get right, do you have quality measuring tools??? You'll need a good torque wrench for the cam bridge and caps. They're a machined set to THAT cylinder head. 0 room for error.

But please, do step 1 and 2 before anything. And whatever you do, don't let the tuner that tuned it to that graph ever touch your car again.

 

[Vermess]

@Enlight as for the 11mm pump, I've never used it on single AVCS engines. Just dual, ie, sti heads. But if you and the builder recommend it, go for it.

One upgrade I'd highly recommend is the killer bee pickup and pan.

 

[Enlight]

One upgrade I'd highly recommend is the killer bee pickup and pan.

I have those already too, but if I'm going to have the engine apart I might spring for the IAG competition pan. I can sell the old Killer B stuff as a set.

Brother, before you jump in head first, entertain this for a bit. Take off a timing cover, make sure that it's not the timing tensioner.

Second, unplug the vvt solenoids and see if it does it.

I've had great luck with cleaning the intake sprockets. But with age, it's cheap insurance to replace both.

Are you familiar with assembling subie heads??? Them buckets aren't easy to get right, do you have quality measuring tools??? You'll need a good torque wrench for the cam bridge and caps. They're a machined set to THAT cylinder head. 0 room for error.

But please, do step 1 and 2 before anything. And whatever you do, don't let the tuner that tuned it to that graph ever touch your car again.

I will check it when I do the tear down. I started her up yesterday and heard a loud audible knock for the first 5 seconds of start up before it went away. I do have torque wrenches but no feeler gauges or micrometers, but as I mentioned, I would be leaving the more complex head work to Headgames Motorworks.

 

[Vermess]

I have those already too, but if I'm going to have the engine apart I might spring for the IAG competition pan. I can sell the old Killer B stuff as a set.

I will check it when I do the tear down. I started her up yesterday and heard a loud audible knock for the first 5 seconds of start up before it went away. I do have torque wrenches but no feeler gauges or micrometers, but as I mentioned, I would be leaving the more complex head work to Headgames Motorworks.

Ok. Make sure they install the cams and label the buckets for you.

 

[Impatient]

What is it about owners of older Subaru (that generation Legacy in particular, as well as the WRX / STI crowd)?
Notice my signature block. I haven’t been on any Subaru forums looking at oil discussions there lately.

anyway, one comment for when (if) you get this sorted out: once upon a time in the good old days, Rotella T6 5w40 had dual certifications: for gas and diesel (and was a darling among EJ25 owners). The certifications changed. I believe today’s T6 (except the recent T6 MultiVehicle 5w30) dropped the gas certifications. Im not saying that T6 broke your engine, but with all the money you‘re talking about spending, maybe it’s not the most suitable oil??? A local Subaru-specific tuner liked Amsoil Premium Protection AMO (10w40) last time I was talking to them. It’s an old school high zinc formulation, suitable for gas and diesel. I never used it, but they liked it. I’ve been using Castrol Euro 0w30 oil (allegedly significant PAO) but I’m not flogging the car like you appear to be (my motor is bone stock). I’m a total hack on oil, but I think a high HTHS is what all these oils share. There are other Euro oils with high HTHS, and I’m sure HTHS is not the only consideration (for instance, T6 probably still has good HTHS, but something else might have changed making it less suitable for gas engines….or maybe it’s all marketing ).

 

[Enlight]

What is it about owners of older Subaru (that generation Legacy in particular, as well as the WRX / STI crowd)?
Notice my signature block. I haven’t been on any Subaru forums looking at oil discussions there lately.

We're all a little crazy. That was the last generation that these wagons were offered in manual. I remember when the formula for T6 changed. I have also dabbled with Motul 8100 Xcess 5w-40 and Amsoil 5w-40s. With the upgraded oil pans and less track driving I recently switched back to some T6 I had left over (those Motul oil changes were $$$). If (when) I get the new engine in I will be abiding by IAG's Motul and 2,500-3,000 mile interval recommendations.

When I first purchased my car in California and drove it back east it consumed zero oil. That got me lax until the consumption issues crept up, probably due to the track days. I will continue to do UOA's on the new engine since I think it will be fun/interesting to keep track of a forged engine with a coolant pre-heater.

 

[Vermess]

@Enlight you mentioned east and a coolant preheater.

Up in NH I complimented a gentleman on his LGT. His mods sounded similar to yours. You wouldn't happen to be in the Lincoln area, would you???

 

[Enlight]

I haven't been up that way in a long time but it's very pretty up there.

Just ordered an Eberspacher S3 coolant pre-heater that will hopefully arrive in time for my travels abroad next week, the vendor is not allowed to ship directly to the United States. I think I will be claim back VAT tax as well, shaving off a total of maybe $500-$600 what I would have to pay here. I was up in N. Mass. this past weekend and picked up an engine hoist off of Craigslist as well.