3.0 Legacy - long term issues?

3.0 Legacy - long term issues?

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Discussion

Mars

Original Poster:

7,125 posts

164 months

Wednesday 11th January 2012
quotequote all
Woo a site just for us. Nice one..!!

I've had my Gen-4 3-litre Rn Legacy for over 4 years now. It's done 105K miles and still feels strong. I've just spent money on new drop-links, new rear springs (the old ones had sagged under the weight of the occasional heavy loads) and winter tyres (which will remain on the car all year round.

I bought a SS Y-section exhaust from Hayward and Scott a couple of years ago and a pair of Prodrive tail-pipes.

After all the work, the car feels great again - nice and tight, plenty of grip, no knocks and plenty of power - so I've postponed selling it in favour of keeping it for at least another year. Thing is, apart from regular servicing, I've done nothing to the engine, and not even an oil change for the gearbox and diff in ages. It's a pretty un-stressed engine (although I do drive it quite hard) but I'm concerned about it's long-term health. I would add that it doesn't smoke or behave in anyway other than perfectly, but...

Will the cam chain need replacing at some point? It's not even a noted service item on the service book (which runs out at 70K miles). Anything else worth considering to change with the engine?

What about the autobox? It wasn't used on the Legacy diesel because it couldn't take the torque (I believe). Is this a concession that the autobox isn't a long-term design? I should probably get the oil replaced (last time was probably ~50K miles).

Diff too... I've convinced myself that it's whining a little. An oil change should help here too.

Torque converter... is the oil in this different to the gearbox?

Thanks.

AWG

843 posts

106 months

Wednesday 11th January 2012
quotequote all
Are you going to do these jobs yourself...?

Mars

Original Poster:

7,125 posts

164 months

Wednesday 11th January 2012
quotequote all
No no - it's my commuter so I pay people to keep it in good health, however with the service book only extending to 70K miles and my NOT normally taking it to Subaru for servicing, I am not sure whether there are jobs that a "standard" service at my local (but trusted) garage need to be advised to undertake.

Mr Gearchange

5,858 posts

156 months

Thursday 12th January 2012
quotequote all
My Spec B is at 130K now.
Still on the original clutch - sails through each MOT. Still feels bulletproof.

I'm beginning to think it's immortal.

Mars

Original Poster:

7,125 posts

164 months

Thursday 12th January 2012
quotequote all
Mr Gearchange said:
My Spec B is at 130K now.
Still on the original clutch - sails through each MOT. Still feels bulletproof.

I'm beginning to think it's immortal.
Thanks. I have this same feeling about mine too - I'm just trying to make sure I don't neglect anything out of ignorance.

This is the best car I've ever owned, and that's in the context of Caterhams and a Cerbera too. Not the fastest or most exciting but when you take into account how easy it is to live with and satisfying to drive/own... easily the best..!!

AWG

843 posts

106 months

Thursday 12th January 2012
quotequote all
Then you may as well throw the cash at keeping it that way, not sure about the chain? Maybe someone on here could shed more light on that, would imagine if that goes it could be an expensive problem.

ScoobieWRX

4,863 posts

176 months

Thursday 12th January 2012
quotequote all
It's the same with any other car but important more with Subaru because of the high performance nature of the engine and drivetrain. If you keep right on top of servicing there's no reason why the car shouldn't just keep going on and on.....

There are plenty of modified and mapped Impreza, Forester and Legacy that have covered over 100K miles +, and are still running as tight and reliably as a car with half the age and mileage, or less. Probably the main reason for this longevity is the fact that as well as being driven sensibly the cars have been serviced properly since day one.

Do a full fluids and filters service to make absolutely sure the car is tip top, always using the best fluids you can afford, and then just do an oil service in between main services. IMHO that's a good way to treat you car whether modified or standard.

Then...a few minor mods and REMAP REMAP REMAP!!! hehe

Mars

Original Poster:

7,125 posts

164 months

Thursday 12th January 2012
quotequote all
AWG said:
Then you may as well throw the cash at keeping it that way, not sure about the chain? Maybe someone on here could shed more light on that, would imagine if that goes it could be an expensive problem.
I've always thrown money at it when necessary but without guidance in the owner manual, it's hard to know where to throw that cash now.

I'll try Crossroads Subaru - see if they'll take on a part-service to address anything local garage doesn't do as a matter of course. If nothing else, gearbox and diff oils seem a sensible change.

Mars

Original Poster:

7,125 posts

164 months

Thursday 12th January 2012
quotequote all
ScoobieWRX said:
Do a full fluids and filters service to make absolutely sure the car is tip top, always using the best fluids you can afford, and then just do an oil service in between main services. IMHO that's a good way to treat you car whether modified or standard.
The nature of the servicing I have means that instead of a full service followed by an interim service every 10K, I have a full service everytime, and with synthetic oils everytime. However, because the garage I use is not a Scooby garage, they tend to concentrate on the "normal" items like engine oils, oil/fuel/air filters, etc.

ScoobieWRX said:
Then...a few minor mods and REMAP REMAP REMAP!!! hehe
If I could only purchase the software and connection lead anywhere, or even determine whether my ECU is programmable (Crossroads thought not - but that's not necessarily right) then I'd almost certainly see about a tweak here and there.

ScoobieWRX

4,863 posts

176 months

Thursday 12th January 2012
quotequote all
Mars said:
ScoobieWRX said:
Do a full fluids and filters service to make absolutely sure the car is tip top, always using the best fluids you can afford, and then just do an oil service in between main services. IMHO that's a good way to treat you car whether modified or standard.
The nature of the servicing I have means that instead of a full service followed by an interim service every 10K, I have a full service everytime, and with synthetic oils everytime. However, because the garage I use is not a Scooby garage, they tend to concentrate on the "normal" items like engine oils, oil/fuel/air filters, etc.

ScoobieWRX said:
Then...a few minor mods and REMAP REMAP REMAP!!! hehe
If I could only purchase the software and connection lead anywhere, or even determine whether my ECU is programmable (Crossroads thought not - but that's not necessarily right) then I'd almost certainly see about a tweak here and there.
What year is it?

ScoobieWRX

4,863 posts

176 months

Thursday 12th January 2012
quotequote all
It should be mappable, it still has a Denso ECU however, it's normally aspirated in Rn guise i think therefore gains won't be anywhere near what you could get from a turbo version but i suspect that H6 motor would lend itself well to some very useful increases in Torque rather than bhp.

Mars

Original Poster:

7,125 posts

164 months

Thursday 12th January 2012
quotequote all
MY05

I would be interested in trying to to better bridge the noticeable crossover between the closed-loop low-rev settings and the (I guess) open-loop settings about 4000rpm. As it stands, there's quite a step. I don't believe the step is anything to do with variable valve timing or variable valve lift, even if my car has such. The step seems too violent for that.

I would also be keen to put a wideband lambda onto the exhaust to determine whether it's overfuelling. The Subaru flat engines are historically thirsty but I've never heard an explanation which satisfies why. If it could be trimmed slightly, it might be worth it as I've put up with the 19mpg average for the past 80K miles. Oh well. smile

ScoobieWRX

4,863 posts

176 months

Thursday 12th January 2012
quotequote all
A remap would address all your points. Turbo Subaru all run rich during open loop running as standard. I'm willing to bet normally aspirated subaru do too.

Modifying the exhaust by going decat and fitting a performance panel air filter would help performance and engine breathing no end, and would get the best out of any mapping. To be fair it's just timing, fueling and MAF curve scaling you chiefly have to worry about on yours, so much more straightforward than a turbo car.

Get yourself an Innovate LC-1 Wideband, it comes with software for your laptop so you can see and log fueling on the move. You could always get yourself an EOBD Laptop cable and software or hand held device to check other things out like air flow, timing and narrowband lambda sensor readings.

As far as mapping your own car is concerned, sure, why not? But, you still need to know exactly what you're doing.

Mr Gearchange

5,858 posts

156 months

Friday 13th January 2012
quotequote all
It's not a turbo charged engine.
So it's all well and good everyone shouting REMAP - but it won't deliver very much.

Also IIRC the ECU isn't very easy to map.

ScoobieWRX

4,863 posts

176 months

Friday 13th January 2012
quotequote all
I cannot find a ROM for this Legacy at the moment, there will be one around somewhere. I'm pretty sure it will be a Denso ECU and it will be just as mappable as any N/A Impreza or Forester or Turbo newage+ Subaru.

Doesn't matter if it's a 16-bit or 32-bit Canbus ECU with DBW, it will map.

The software i use will allow me to download the ROM and create ECU definitions specific to the ECU if i don't already have the definitions so it can be altered and flashed back to the ECU.

As far as i'm aware there is no current N/A or F/I newage or newgen Subaru that cannot be remapped as per normal with either EcuTek or Open Source, and that includes diesel subaru.

ETA: Simon (JGM) might be able to confirm that one way or the other.

Mars

Original Poster:

7,125 posts

164 months

Friday 13th January 2012
quotequote all
Mr Gearchange said:
It's not a turbo charged engine.
So it's all well and good everyone shouting REMAP - but it won't deliver very much.

Also IIRC the ECU isn't very easy to map.
I'm not really after a huge power increase, and rolling roading an automatic is never much fun especially because the Legacy changes up even if you're in "manual" mode.

I would just like to tweak it a bit. Cleaning out the MAF sounds like a sensible suggestion. I already have replaced the exhaust for a H&S SS Y-section and Prodrive tail pipes but any restriction is likely to be with the manifolds and catalysers which I haven't changed and don't plan to.

The air-filter is standard but gets changed at every service regardless.


I am accustomed to tweaking maps (my Caterham/K-series engine with Emerald ECU and LC-1 WB lambda). It'd be nice to connect to my ECU and have a look at the options, and see if I can log the output of an LC-1 against MAF and revs. I'd also like to measure the revs/MAF of the typical speeds I sit at on the motorway to ensure any settings changes I make leaves me within the CLOSED loop section at those speeds. Suspect that it wouldn't be hard to improve upon the power settings without damaging the economy because constant speeds tend to come from smaller throttle openings (lower MAF numbers).

I'll have a look for a suitable cable and software. Thanks for the assurance - I thought it was likely to be a non-starter.