Its saturday afternoon and time is of a plenty so thought id chuck a discussion thread out there

So, with all sorts of ranges of engines letting go, low mileage, high mileage, new, Old, tuned, not tuned, theres never a direct link to say an old engine means the rod knock will occur

So, is it poor maintenance, poor quality oil, poor mods, poor mapping and more importatnly is it always Knock that lets the engine fail or oil starvation etc ?

 

Any combination of all of the above and more.

Most people don't know why their engine went.

Mine was broken pistons due to gudgeon pin flex, just one of those /**** happens" things...

 

I believe Rich's engine had been built by someone else, before he had it, so you don't know to what standard that was done.

Plus the Impreza's are normally driven hard, and your Impreza could of been owned by 2 old men that didn't take it over 50 (unlikely) or 2 boy racers who thrashed it to death and never looked after it. Or may have super low miles but had been used mainly as a track car so hard life, or well looked after garage and oil changed every 2000 miles like mine

The problem is no one knows how there car has been treated in the past, if its been run low on oil etc.

All you can do is try your best to find a good one, that means loads of service history, bills, few owners, garaged etc.

 

Poor tolerance's ,poorly made , mass produced - bad eggs in the basket
It's a can of worms your question

 

You could ask why does the 1990's Legacy 4cam turbo (the original WRC Scoob ) go on for inter galactic miles without a issue. So much so they have a high mile club.

This was the car that gave Subaru its performance+reliability reputation.

Next most reliable is the pre-97 Uk Turbo 2000. Not uncommon to see these with well over 100k on the original engine...unlike the post 97 version. Things went downhill after that.

 

Mine went bad recently,still not 100% sure on the problem until I split the block.
The car is,according to the paperwork and previous owner supposed to have a GG off the shelf forged short block with cosworth internals(so wasn't fitted by GG)
I also can't confirm it is the short block which is on the paperwork?
Was built in 2008(30k miles ago) so could have been swapped at some point?
On checking valve clearances we found them all to be extreamly tight which would indicate no head work was done on the rebuild or as I said the engine is not what I first thought?
And I've only had the car 6 month before problems stated so I've not had much chance myself to drive it hard.

When I got the car home I did some data logging and found the car to be detting badly and running super rich on cruise(remap had recently been done when the twin scroll set up was fitted) Also over boosting quiet badly.
So I guess there are plenty of reasons for my engine failure?
Thanks to a very kind member on here johnlogie I have been given a short block,I will put my heads etc on this to get me back on the road,then start to pull my engine apart to see if it's worth rebuilding.

Cheers
Rich

 

Because there driven by old men

 

Post 97 more imports came over with mapped for japanese fuel, weak maf on the MY99-00 and early tuning days of fuel cut defenders with bleed valves...

 

People don't realise that built engines don't last like factory spec ones. Used properly and regularly they need rebuilding regardless of the swanky parts list.

Factory engines die because they're old or have been owned by bellends mostly. Well except the epic 2.5's

 

Of the seven Scoob's I have owned of various engine size, UK/JDM and type only one let go.

A 100K+ V5 STi. The car is now with a new owner, new forged engine and 120k + on the clock.

 

Some good replies so far , I know the question has unlimited reasons but as said in this topic , even rebuilt engines aren't lasting - why ?

I'm the only uk owner of my 95 WRX , it had 60 k on clock (km) now has 112k miles ( I reset the counter when I converted ) oil changed every 5- 7 k with magnatec , an oil swarn to be dreadful for these cars and now as I've mapped it running 10/50 Titan Fuchs oil , I've replaced most serviceable parts along the way also .

The only thing to fail so far was gearbox

Suppose it's luck of the draw but it intrigues me there's always an Impreza with rod knock for sale every week

 

Never heard anything but praise for the reliability of subarus.

The only things that ever get brought up are HG issues, Ringland failures, suspension and rust. All of those are only on certain models/variants too.

Engine knock is often because of bad tunes, wrong fuel, bad maintenance, bodges or all of the above.

A lot of the issues that get brought up are due to the drivers, that is a lot of bellends tend to buy the cars and drive them like a bellend would = lots of donuts and bouncing off the redline with poor servicing = oil starved motor = loud knocking sound from the block.

 

Interesting thread. I'm currently debating re-mapping my wrx, it's an 80,000 mile 3 owner wagon with ppp and a massive file full of well documented history. But I keep reading about engine failures which makes me nervous.
As have been mentioned before I think most of these cars get a far harder life than most saloons and get driven closer to the max of their designed performance for longer.
Having said that, I wonder what proportion are still on the road per year of manufacture, compared to other high performance saloons?

 

Is it an import or just remapping for tune-up/re purposing?

 

Just a tune up. It's a 10 year old car with 80,000 miles on standard internals. And a daily driver. I was going to go for a de-cat up-pipe so have that mapped in, with possibly a 3 port boost solenoid and a new fuel pump.
No more than 275 to 280 bhp. Honest.

 

I've never done a remap for exhaust swaps but then again I've never de-catted, wondered if I should have or not

Need to save up for an ECU and a remap though because I've gotta get a car remapped to brit fuel which means keeping the revs low and hoping tesco doesn't skimp out on its RON for a few months.

 

Poor maintenance (on anything other than 2.5's)

My bug has 135k but has been serviced regularly, and maintained regardless of cost. I can go to that car after a week and it fires up instantly without the slightest untoward noise and it runs like a top.

 

Was it you who has the upside down remote oil filter which cannot be prefilled.

Prooves the "priming the oil filter routine" is a myth.

 

If it's a 2.5 about 10k milage no matter what you do to em hahaha.

All joking aside can depend on anything from how it's treated to how balanced the engine comes out the factory

 

Ha yes it is , upside down and located behind drivers headlight lol

 

How about we start a high milage engine leader board. With tips on how to get there?

 

I've owned 6 scoobys the only 1 that went wrong was the one with the rebuilt engine.

Reason being it went is because some IDIOT rebuilt it. Nothing was right about it really poor job.

Had it rebuilt and has run spot on 6 years and still going strong for the new owner.

Think I may buy other to go along with my Evo 9, R34 GTR, Nissan GTiR and Cossie.

Prices have gone up by afew k since I lasted owned 1 and it was hard to find a good car back then.

 

every engine on a scoob i have taken apart on seen apart has had the screws loose on the back of the oil pump,my current one 68000kms had loose screws when we changed the cambelt as a precaution, screws where then refitted with screwlock, could loose screws result in low oil pressure ?

 

I've never had one engine fail in seven Impreza's. That includes my first which was a V2 WRX with an old ebay FMIC, Walbro pump, Apexi IK, MBC all brought together with an SB ecu from a version 1 STI RA.

The car made 313bhp on 380's running 1.1bar. I also done two airfield days in that car and drove it like I stole it!

Mapping is over rated..

 

Only had one engine let go UK Bug WRX but that was my fault for driving it like a bellend , dropped another engine in and converted to avcs then crashed it into a tree 2 months later and that was that...have had Spec-c's for the last 5 years with no engine problems just a 6speed synchro issue on an MY03 Spec-c

 

That's a good point on the oil pump , I've had mine upgraded by API a few yrs ago , still think it's s 10mm but they modified them

 

Are you sure it had a synchro problem?

 

Mine is an 05 WRX, I bought it with 98k on the clock, not many reciepts, but the 2 previous owners (mum and daughter) were multi millionaires, they just said to the garage 'do what needs doing'. In the 5 months before I bought it they spent £1,500 on new roll bars and bushes, new discs and pads, calipers rebuilt with new pistons and fluid.
Before I did any mods I put it on the rolling road to make sure everything was ok, it made 242bhp , not bad for a standard 98k car. When I replaced the turbo, the oil seals had gone on the old one, I always wondered what it would have been like with a new, standard turbo. Now running 330bhp and drives great, you'd never guess it had 112k on the clock

If it's not mapped stick to v power
Some mappers and rolling road operators can tell the difference between tesco and shell 99 ron fuel. Tesco 99 is nicknamed 'random det'

I have had a couple of issues with det from tesco 99, but since using v power it has been fine

 

I have never had an issue with tesco fuel I'd be looking for other issues than the fuel.

Done 30k miles on tesco fuel at over 500hp with all the launch control etc.

All brands will sometimes have issues contamination etc. But ultimately they are all made to the same bs standard....

 

True. One important thing to consider that so many people are naive of is the BS (BS7800) standard for super unleaded is made to -the one that is legally enforced. States the Minimum octane to be 97ron (when tested according to ISO5164). That means VPower "advertised" at a "claimed" 99ron only has to be 97ron to satisfy legal regulations and licensing to sell the fuel. This is strictly enforced. It only needs to be 99ron to satisfy the advertising standards agency, which is not strictly enforced as anything severe would have to referred to trading standards.

By labelling something as "VPower" or "momentum" or "Ultimate" they can sidestep most of this as they aren't actually openly advertising the actual octane. 95ron normal unleaded however should always be 95ron.

I've always maintained this fact that mapping for a fuel higher than 97ron without proper knock control poses a risk to your engine if it's running high than standard power levels. Simply due to the fact you don't really know if the fuel going into your tank has lost its aromatics from evaporation and sitting in the forecourt tank for a few months.

This applies ALL brand of super unleaded fuel.

I first noted this problem about ten years ago because I have 2stroke motorbikes, and they are a bitch if the fuel loses its octane from storage. And because they don't get ridden a lot, it only takes a few month for fuel in the fuel tank to "go off" because the base fuel now relies heavily on very volatile components that evaporate very easily (even through rubber). Also the ethanol (which ALL petrol contains regardless of brand or octane) is wrecking the brass components in the carburettors. Every year I have to strip the three carbs off my H1 to get it running, as not only does it rufuse to ignite stale fuel, the corrosion in the float bowls has blocked the idle jets with blue/green oxide deposits.