CarlsWrx

Hey all, I live in the Cayman Islands and this is my 3rd scoob that has given trouble with engine bearings, either spun or eaten it, can anyone help me to understand why this happens and does it make sense for me to once again rebuild or rebuild and sell and get a GDB, I have heard they don't give that much trouble. I love my GC's but hate headaches. The car in question is a 99 Version 5 STI, I have owned a 96WRX and a 98 STI, I welcome any help / knowledge you all can pass my way. Thanks

dpb

What fuel do you have there ?

Splitpin

We can't tell you why your cars suffered bearing failure without having physical access to those engines and disassembling them. There are a variety of repetitive causal factors for bearing failure - from oil pump (or pressure relief valve) failure to pre-detonation (especially on a car mapped for Japanese high octane fuel) to the possibility of transient oil starvation caused by oil change, underfilling or surge.

As for what you've heard about newage cars being less prone to it, they do have some revisions to the oil system, but any suggestion that this problem has been "cured" is undermined with a quick search of this forum.

P555SBR

iTrader: (1)

dont take this the wrong way but to have 3 engine failures on 3 different cars sound to me as it may be down to something your doing more than the engine i have a 96wrx running about 340bhp and its had alot of hammer over the 2 years iv had it with no problems at all (jinks now)id be tempted to look at what oil your useing and fuel grade

CarlsWrx

No, I value all the info that is being offered, we have 86 and 93 octane, higher octane has to be imported and is mostly done for track use. Cars have all been serviced regularly, oil used Castrol Synthetic 10w-30 or when higher engine mileage is on the car my mechanic suggest's quakerstate 20w-50, pump in all cars with the exception of the 96 wrx are stock, after the rebuild it's all fine, its hard to get parts here for GC8's they either have to come directly from Japan, or try to get them from your side of the pond. I appreciate all your help/ suggestions.

Splitpin

Cripes. Your STi version 5, in particular, will be mapped to run on Japanese 100+ octane fuel. Are we to take it you use the 93 + loads of octane booster?

Does your mechanic know enough about these cars to pre-fill and pre-prime the oil system prior to startup after an oil change?

dpb

dj219957

as above. 93 octain fuel is your problem. your car will need 97 ron or more.
your engines are failing due to what is called "pre ignition", "pinking" or "det"

either find some better fuel or have the ecu re-maped.

dj219957

also, use a 10W40 oil. this will protect the engine better when it is hot compared to a 30.

its a middle of the road oil for a scoob.

CarlsWrx

Does your mechanic know enough about these cars to pre-fill and pre-prime the oil system prior to startup after an oil change?[/quote]

I use 93 octane and octane booster occasionally,

I believe he does, he has over 20 years experience, however could you
explain this process so i could maybe do it myself

Ginge !

iTrader: (1)

its your fuel mate simple as that im afraid

CarlsWrx

Really, never thought it could be the fuel, as for Re-mapping ecu's there is no place here that offers that service, would i have to maybe get a safc or something?

Splitpin

As the others have said, it sounds like your fuel selection is a significant part of the reliability issues you have faced. You need to be raising 93 octane over eight points to get it into the range an STi5 is mapped for, so to hear you only use booster "occasionally" says a lot.

As far as the oil change procedure there's already a lot written on it round these parts - have a quick search and you should dig it up.

dpb

and dont forget the bells round your ankles

Splitpin

Your point being?

scoobiewrx555

93 Octane is like 98RON in Europe so not too bad but when the ECU has maps for 100RON you've got to use Octane Booster. Perhaps you can get hold of Methanol or Ethanol for 5%-10% mix with 93Octane fuel to properly raise your Octane number much higher than using an octane booster.

I wouldn't be surprised if all your cars have been detting their ***** off and this is why you've had bottom end problems. You didn't mention if you use Semi-Synth or Fully Synth oil whatever the grade.

BTW... Cayman Islands sounds very nice. I'm on my way!!

JohnD

iTrader: (5)

It also sounds rather warm! Another factor to dial in?

JohnD

JohnD

iTrader: (5)

I believe reference is being made to part of the fabled "**** oil change procedure" If memory serves me correct, it comes just before "disconnect crank sensor and churn engine on the starter motor, whilst whistling God save the Queen"

JohnD

CarlsWrx

Temps here are mostly in the mid to high 80's yes it gets that hot sometimes, as for the meth, if I'm understanding correctly, a meth kit would keep me in the safe zone so to speak with fuel, the oil I use is fully synth, what's been happening here also is most gc guys swapped in the 2.5

Splitpin

Gosh, aren't you the comedian?

Maybe you'd like to explain to us why the major Impreza specialists carry out that procedure, or maybe you'd like to read the second part of this and offer us a technically grounded counter-argument?

dpb

I can hardly credit it that anyone could blow 3 engines by , most likley , using fuel 10 ron less than it should have splitpin

just quietly putting forward the possiblity we have another lewis start-up aliias

Splitpin

Can you re-phrase that in a manner that makes sense? Are you saying that you find it unlikely that someone could have blown three engines by using low octane fuel, or are you saying that you believe this is the likeliest explanation and thus there's no need to look at alternatives. Or...?

I also see you've failed to answer my question, which says a lot.

What is a "lewis start-up aliias"?

KAS35RSTI

iTrader: (73)

93

dj219957

the op has not yet clarified if hes using 93 RON or 93 Octane. Theres a big difference.

JohnD

iTrader: (5)

I was simply quoting from previous threads on oil change procedure. It's not necessarily my opinion! You obviously haven't had the pleasure of reading these threads. The reference to "Lewis" is the input to these threads by the legendary PSLewis
I will say however, that with the boundary layer of good quality oil held in the bearings, an engine should not suffer damage for the couple of seconds (at the most) before oil pressure is established under minimal load conditions?
The handbook makes no reference to even pre-filling the oil filter, although why you wouldn't, is beyond me!

JohnD

scoobiewrx555

The OP has already told us he uses 93 Octane

Splitpin

No, you were quoting "previous threads" in a very specific manner, as evidenced by your use/quote of the words fabled and "****", along with the reference to singing a silly song, thereby suggesting you were taking the p*ss.

If it's not your opinion you need to learn to express it a little more clearly.

I know who PSLewis is, what I wasn't sure of was exactly what dpb meant by "another startup alias", given that nobody posting on this thread is exactly new to Scoobynet.

Are you asking me or telling me? You can suggest the above if you like, but the recurring scenario of bearing failures in the minutes/hours/days following an oil change suggests that despite what you might believe, these engines do and are suffering bearing damage in the moments before oil pressure is established. For the third time, read the theory I linked to above and come up with an equally well grounded and explained reason why you think it's wrong.

Your point being? The owner's handbook doesn't tell you a load of stuff that is both important and obvious. The various service manuals contain errata that will result in serious problems if you don't use your common. Moral: Just because the service manual doesn't mention it, doesn't mean it ain't a good idea.

So you do carry out procedures that aren't in the manual then? Doesn't that undermine what you've just said?

Ginge !

iTrader: (1)

please dont attempt to start a debate blaming semi synthetic oil over fully,,,,, these days oils are SOO well refined that on a general road going car even with the engine thermals of a impreza it aint gonna cause him to spin a shell,,,, even if he leaves if for 10k miles between changes,,, track use or very high speed driving AND DOING IT REGULAR then yeah he will need it but the temps for the shear values of most semi's is alot better than people give credit for

ive used semi synthetic for road use in my scooby,,, carlube tripleR and change to fully for track use/when i go to the ring or in the summer when the car gets a pasting on motorways,,,, winter time i use semi synthetic and the engine is fine after 20k miles !!!

same with the " prime the engine first" bollocks,, fill the oil fiter IS a must ill agree but priming is just a load of bollocks,,, where you thing the engine oil sits when you stop the car ???,,,,, and do you REALLY belive you drain ALL the oil out of a car when you change the oil ??? theres always old oil in the parts you are priming like a numpty moving it about,,,, the engine is still spinning ffs hence you are priming it ,,,, or you think that its turning at 2rpm when you disconnect the coil pack ? if so how does the pump get up to presure to pump the oil about ??? think about how the pump works and how a engine REALLY works

Yox

Please don't start a debate?

eggy790

iTrader: (20)

im confused at these oil changins tuff