HELP! engine knocking after 4k on forged rebuild
 

without boring you, heres what happened>

pulled up at home after a stead drive home from the gf's, cooled car down as always. came out to the car the following morning started it up, after 5 secs a knocking sound came from the engine bay so i shut it off immediatley and called the engine builder who said bring it in. im not gona lie, the car does get sum stick but it is well looked after by the engine builder, its been in his hands every couple of months after the build for a check over and oil changes etc. ive done the obvious like check all the levels etc and all are perfect........as ALWAYS!! im asking for any advice as to what may have caused this......im assuming bottom end failure......the car is a 1998 sti import wagon, as said above, its forged, CDB, stage 2 crank, got 6 speed box, de cat, mapped apexi ecu to approx 310. the build cost me 4k and im damned if im paying another 4k!!!!!!!!!!

any help would be much appreciated lads

without being specific, is the engine builder well known on here, if they are im sure they will look after you assuming you haven't caused the problem yourself. If they aren't well known maybe you picked the wrong builder.

Could be anything really mate, not nearly enough info here! The cause of the failure is what your engine builder should be determining!

Did the car suffer an engine failure before it was forged or was it just upgraded? If it did suffer a failure, was the cause determined? If not, the same things that caused it to let go before may have just reared its head again. Any warning lights prior to it letting go?

I'm afraid if the engine was out of warranty, you're either going to have to shell out for another build/replacement engine, or cut your losses and walk away!

Ns04

Its been built 6 months ish, I don't understand how I would hav caused this? I have maintained the car.....shurley the problem is mechanical?

And yes, the engine builder is a very very well known guy, if u have a subaru and don't know him, there's something up

Who did the build ??? Not saying I'm a expert mine just dropped you see its at API at the mow haven a build I was told they is a number off things

my engine build came with 10k warranty or one year whichever first, did you have any kind of warranty on it?

if you have abused it as you say then to me that says it all, sorry just stating what you have wrote,.

Driven hard and abused are two different things.

Was it properly mapped for all mods & were there any running issues before knocking?Did the builder diagnose bottom end or are you assuming as it may be something else.

4k build and you went for a 2.0l? Whats a stage 2 crank?

Or phase 2 crank?? I may be mistaken. All subarus are driven hard.....so don't gimme that haha

The engine builder did the mapping.....no issues at all before mapping. No issues before knocking, I'd only had it back off him a week before this happened

May turn out to be pulley or knackered idler yet mate;)

Whats a stage 2 crank ?

I have heard a few lads talk about piston slap on forged builds google it and have a look on youtube see if thats what you heard...

why dont you just wait and see what the builder says, pointless trying to guess what could of happened over the internet !

Again who did the build

I'm not naming no names yet as I wudnt want to ruin his credability or the relationship I've got with the builder. I'm hopeful he'll look after me whatever conclusion he comes to

Another thing I forgot to mention which may be significant.....the oil light came on a few seconds after I started the car up, then the knocking started a few seconds after, so I switched off immediatley! Could it be oil pressure? If so....is this my fault? As I said above.....the oil is at the correct level

If that is the case then why post this thread?:wonder:
In your own words you've got a good relationship with the engine builder and he has looked after you in the past. Why would things change now? Furthermore I can't see what diagnosis you're going to get over the internet! A lot it may be this and could be that but how can anyone say definitively without examining the engine?
It seems you put this up to keep the said specialist on his toes.

Things may change now because a fresh re build could be in the balance and it will be either his or me forking out another 4k for this.......I'm sure even if I've got a good relationship with him....he'll still rather put it on me rather than him self.........don't you agree?

As above the engine builder should be able to determine the cause. Was the oil pump changed with the build? (presuming it was @ 4k)

Ant

Yeah everything was brand new!! Just baffled me, as it ran sweet the night before

without stripping the engine down the reason could be anything from component failure, to bad batch of fuel, to bad map, to failed sensor, to not warming it up properly before giving it stick, etc etc etc aka anythign could have happened

310 is very low power for a forged cdb build, so i doubt its a overload type failure, aka driving it to hard (unless not warmed up properly first).

get diagnosis first then go from there. untill you know the cause your wasting time worrying about it. Also if the builder is as well known as you say and has a good rep im sure they will treat you right if you let them figure out whats going on insted of going off on forums.

Is any one thinking the same thing hear :cuckoo: If you only had the build done 6 months ago and you ran the car in , (with the right oil ) done every think right 1st and paid 4k for a build thats gone pop allready Its not looking good for the chap who did the build is it ?

Also to be fair to who ever did the build if you been driveing it around like you stolen it every day that could be why :thumb: without stripping the engine down the reason could be anything from poo fuel, to bad map, to not warming it up properly . But I belive if you had a good build and good map which thats why you pay 4K for it should last longer then 6 months around 1000 miles need to be done to run a full build in even then you should take your time until the cars settled down

API have my car at the mow and iv been told around £3500 mark for the build and thats a really really really good build any think over 4k your looking a forge stuf :eek:

Not if he's honest he won't.

If it's out of warranty, you WILL be paying regardless, so this speculation is irrelevant.

Without an independent inspection, you will have no way of refuting any claims made from the strip down! If that inspection revealed that there was nothing very obviously wrong with the build from the outset -tbh If there had of been, the chances are it wouldn't have lasted 6 months of hard use- then the builder is in the clear as there are a whole host of other things that could have gone wrong beyond their control e.g. component failure (OEM oil pump pressure relief valve sticking open not a totally uncommon fault), dodgy fuel etc!

Expect to have to pay for this I'm afraid!

Ns04

What oil light?
Please don't tell us you forkd £4000 for a rebuild and DIDN'T have an oil pressure gauge fitted to monitor oil pressure? :eek:

+1 :thumb:

Its a bit late to be telling you now but you cant rely on the oil light. The oil light coming on is like a flash when a nuke goes off, its too late the damage is done.

My point in a nutshell:(