It seems that the bottom end bearings in the boxer engines are made of cheese on some cars

I know that on the old Mi16 engines, oil starvation was the achillies heel and a baffled sump, longer oil pick up etc helped this problem significantly (short of dry sumping).

So, are there any real prevention techniques that can be adopted, and has anyone really figured out why the bottom ends go so regularly. I'm aware that knock will seriously damage them, but what about on an otherwise 'good' engine?

Fingers crossed mine hasn't yet (kiss of death there ), and if it did, I'd be keeping the standard post of 'welcome to a 2.5k rebuild cost' in my pocket and doing it myself.

Any suggestions?

 

-use the correct fuel
-dont up the boost with bleed valves - get it mapped properly.
-pre-fill the oil filter when changing the oil
-dont over rev it
-warm it up - cool it down properly
-jump up and down on the spot twice, turn around and pat your head before you get in the car every morning.

 

-jump up and down on the spot twice, turn around and pat your head before you get in the car every morning.

I have had 3 engine builds in 12 months (mainly due to chimps building my engine ) and from my experiance all the above and also the fitting of usefull gauges Like, knock link, Airfuel, oil pressure and temp ect...

Use 10w 50 or 15w 50 oil and dont over rev, had Andy F map my latest engine yesterday and we set rev limit at 7500(STi V3), he said not to go past 7.

 

my wrx red lines at 7. i dont take it past 6.5
Its hard to remeber sometimes as i also have a civic type r which you have to red line evey time if you want to use the v-tec

 

Dont drive it

 

better than mine

 

Dont cane it! So many engines let go within a week or two of your owning the car and theres a reason for that.

 

if u drive it like you stole it and rev the hell out of it and dont warm it up or cool it down then you are asking for trouble!

 

As above:

-Run it on the best fuel you can, especially if its mapped for a particular RON
-Ditto for consumables like Oil. Fully Synth all the way!
-Service it according to Subaru's schedule, don't neglect the car.
- Drive with mechanical sympathy: warm up cool down, don't bounce it off the limiter everywhere etc
- If you're gonna mod the car, do it in consultation with the experts, don't just wind up the boost and hope it holds.

These are great engines if looked after and tuned by those who know what they're doing!

Ns04

 

So it seems that perhaps they aren't all made of chocolate then, good news really.
I was afraid that someone was going to say there was an inherent design problem, but it appears that failure is mainly down to poor driving technique, poor servicing (not necasserally in some cases though )

Cheers

 

I will have owned a subaru for over 5 years come december, and never had 1 breakdown

 

Subaru are renowned for their reliability, I was sort of fishing for why the bottom ends go and to be honest, I got the answer I thought I would. People expect too much from a mechanical device.

Thanks for all the replies though

 

They still go bang even if they're not driven much.

 

be paranoid about your MAF sensor - that was the cause of my P1 engine going bang - cylinder 4 over-fuelled, fuel went down past the piston and the ensuing de-lubrication caused the problem. the shame was that a main dealer swapped the sensor for me - and performed a full service at the same time. engine went pop very soon after.....it's never going to that dealer again. have a local specialist who understands what he's doing looking after it now.

G

 

Wouldn't the warranty cover it if anything did go wrong in that sense? What's there to worry about then?

 

p1's are renowned for going bang i don't think you can blame the dealer for that one

 

You would expect a high performance car to be more robust but hey its a budget one

 

'fraid I can -

It went pop after they'd serviced it (i.e. 200 miles later - as soon as I put my foot down to overtake a truck). Hmmm. At the time I asked on here and the concensus was that they almost certainly hadn't dry cranked it post the oil change.

There are a small number of reasons P1 (and other Sti) engines go bang - and this was one of them.

Luckily I had the extended warranty which covered the re-build - but the main dealers won't be seeing it again.

G

 

Yeah, just like the formula one cars eh

 

Agree with you all the way except the fully synth oil, fully synth is only worth putting in if the car is low milage, putting it in an 80k engine which has never seen fully synth is worthless as the wear in that engine is already there, which is one of the big plus sides to fully synth, reduced engine wear, so not going for that unless its a low milage car, but regular oil changes are good and a good quality oil is recommended

Tony

 

a friend of mine supplies subaru performance parts and engines etc he done a little research and reckons most engine faliures occours not long after oil changes