..

 

engine out, split the block to get at them im 99% sure

 

Not cheaper to replace the engine than split for a rebuild?
Time to upgrade or a replacement WRX block wouldnt cost too much should it?

 

you may then risk putting a w#*ker in though, unless you can be gauranteed it is a good engine (see/hear it running) i would consider refreshing (not re-building) the old one. Better the devil you know

 

..

 

the only bearins are on the bottom end- big ends and mains, it wont be the mains. Could be piston slap?

 

yes sounds more like piston slap now ive looked at a few you tube videos. ive added a video on the original post

 

if it is big end bearings, mine went, cost around 3k for labour and parts - big end, crank, seals etc + 25 hours labour.
if it happened again id be tempted with a sti block....

 

its not though. its piston slap, either way the engine has to come out to fix it i think you could do the work for less than £500 if doing it yourself

 

If it is piston slap you have to go oversize pistons if the bore is out of spec. Then you might as well do the bearings and rings and oil pump. You could use this oppurtunity to employ a stroker kit if money isn't a problem.

 

Your theory of piston slap is a bit contradictory to the above symptoms.
Piston slap will be more noticable with a cold engine and makes itself heard when you accelerate the engine, not lift off. In fact, slap should pretty well disappear when lifting off throttle. Your video seems to show that it's noisy when opening the throttle! If the engine was at normal working temperature, any piston slap shoud be hardly noticable.
I think you should have it listened to by a knowledgable Subaru specialist.

JohnD

 

or any decent mechanic, an engine is an engine

 

or a brand new 2.5 litre bottom end for £1500

 

It's finding a "decent mechanic" I have a morbid distrust of all car mechanics, especially those working in 'all makes and models' garages!
There are a lot on here who would dispute your "an engine is an engine" statement when it comes to the Subaru unit!

JohnD

 

hmmm, i always find the people who work on all makes and models (and have done that for several years) are the best as they are the most open minded.

 

If I had a penny for the number of times I've heard threads along the line of "Engine blown but my mates sorting it - he's a good mechanic/the local garage who are perfectly good have quoted me less than the specialist"

I'd have £1.69!

Seriously though, most of such threads end with another post by the same guy a couple of months down the line saying "it's gone again"

Trust me- these are engines best left to the experts on them.

Do the job properly the first time - pay once. Many have learned this the hard way - at their considerable expense!!!

 

Do you have to use "special tools"? that live in a special subaru toolbox, only used by special subaru experts who use special subaru torque settings and special subaru assembly oil and special subaru loctite with special subaru rags and brake cleaner to clean the special parts. Are all the parts measured using special subaru measuring equiptment? The answer to most of the above is no, normal tools and equiptment can be used, of course you will have to use the torque settings and clearances for that engine, but that goes for any build or component.
It is the mongtard mechanic that is at fault if he cant build an engine that works.
The fact the engine is aluminium (most are these days), and is horizontaly opposed has very little reflection on a decent knowledgable mechanic (someone that can build an engine, not a tyre fitter!) can screw it together if they use the correct assembly procedure, torque settings and clearances.
Another very important fact; "Its gone again" you say above, do you think prehaps the original problem was not addressed? Knackered radiator, too much boost, wrong map, leaking rad hoses/heater matrix, contamination in the intercooler the list is endless, but you cant blame the engine or the builder for one of those faults. Try getting a warranty from a specialist if you overboost/overheat the engine he build for you, no chance!

 

And in a way i would agree with you but most engines out there are very similar, in line 4's, throw a diesel at them and they may be stuffed, flat 4's are not that common so they may not know what quirks that engine has, hence why a speciallist who works on that specific type of engine is more qualified than your normal joe bloggs garage, even though they may be a very good mechanic .

Tony

 

The problem is that most "normal" mechanics these days are stuffed when it comes to building engines properly anyway. For example i have working with me a lad who is timeserved and specialist in VW Audi stuff, although very good with most things he would be way out his depth building a whole engine up. People are becoming more fitters than mechanics now and probelm solving and fault diagnosis is getting harder, and so the ammount of people compedent to do these tasks are few and far between.

 

That aint piston slap, your bottom end had gone.
Budget circa £2500 for a rebuild using oem parts.

 

2500 will buy a whole bugeye with mot and tax

 

thanks for all the replies.
its been looked at by 2 garages, 1 a local all motor garage and the other at a dealer that i know very whell when i had them fix my highly tuned mr2, they were unsure because of the symptoms, it is totally quiet when first started and perfect but as soon as shes at operating temp she will knock and even louder if taken for a high speed drive. no knocking at idle at all just shen revving.

 

Regardless of what it does, IT NEEDS PULLED APPART!

 

true.
what should i be looking for interms of causes? oil pump il change anyway but should i look for blocked oil ways etc

 

I would disagree with that statement hugely, as you say all engines are diffrent and to be honest the only person you want to let near your flat four should be a well known subaru engine specialist/rebuilder, and i think you will find most will agree

 

There's no doubt in mind. The bottom end has gone on that. If it was piston slap it would go quieter when warm not get louder. One way to know for sure. Take it for a gentle drive. Gently accelerate upto 30-40 mph. Then very very gently let off the throttle. Ensure that your not accelerating or engine braking. i.e there's no load on the engine. If your bottom end has gone it will be at it's loudest at this point.

I'm almost 100% that's your issue. Tell me I'm wrong once you've taken it apart

 

There's no doubt in mind. The bottom end has gone on that. If it was piston slap it would go quieter when warm not get louder. One way to know for sure. Take it for a gentle drive. Gently accelerate upto 30-40 mph. Then very very gently let off the throttle. Ensure that your not accelerating or engine braking. i.e there's no load on the engine. If your bottom end has gone it will be at it's loudest at this point.

I'm almost 100% that's your issue. Tell me I'm wrong once you've taken it apart

 

well said that man. few an far between unfortunately

 

not enough skilled people about any more, too many sheep if you ask me

 

And I'd disagree with you (and many others on that);

The flat four Subaru is not anything special, if anything once out on a bench its quite a nice and simple engine to work on compared to many mass production engines (so long as the gudgeon pins aren't stuck ). As such It should be well within the grasp of any competant and well experienced engine builder.

The problem with bad workmanship almost always revolves with lack of attention or poor care to detail and too much assumption. That being proper inspection and measurement of every part, be it moving and fixed to ensure adequate tolerances and specs are met. And just as importantly the investigation of the fault(s) that caused the failure(s) or excessive wear (not just assuming its the oil pump or 'det' ). Not forgetting clenliness and a methodolgy to ensure everything is checked and double checked; not just torn apart and slapped back together with a new crank and bearings.

There are plenty of builders and specialists out there who may preach the above, but in practice don't bother - either to cut costs or speed up throughput (a point which I may add to - don't rush an engine builder to turn round a job beyond what he advices...it can bite you in the **** later on ).

Remember, anyone car tear apart a few Subarus, then call themselves a "Subaru Specialist". So use the "go to a specialist" advice with caution and do your own homework (not relying on somebody else's) before fully committing your car to one.

Reputation is key here - regardless of being a specialist or not. And by reputation, I mean based from the horses mouth; not based on people reccomending someone because 'their mate from the internet 'had his engine fixed by them'. Get my drift?