Doomly

Hi all, any advice will be muchly appreciated. Basically I think and a garage has told me the bottom end has gone on my impreza, lumpy on idle, slight mis fire and tapping noise lots of smoke when started up!

The car had been idling a little rough for a few weeks previous which I was not to concerned about, then unfortunatly on a fast run on the M3 I lost a bit of power like the turbo was not spinning up. I put my foot down again and looked in my rear view mirror, to my dismay lots of smoke and it was struggling to keep speed. The only mods I"ve done are Scooby sport centre pipe, back box and green stuff pannel filter! The cars only done 47,000 miles! Reguarlly serviced and I do look after it. I'm obviously gutted.

Any ideas what has caused this? No lights on the dash to indicate a fault, oil was nicely topped up with fully syntetic! Also is there a better bottom end I can replace it with, or is just a standard re-build or re-conditioned block my best bet?? Thanks

New_scooby_04

iTrader: (4)

Eeek, what a first post!! That's bad luck, but welcome to SN anyway!


Call David at APi and ask his advice mate (they specialise in Subaru engines) and have a great reputation on here. Tell him Ns04 sent ya!

A failed bottom end gives a very pronounced knocking sound IIRC, not ticking.

Did it belch white smoke? If so, my money would be on a melted piston caused by the car running lean owing to a MAf sensor on the blink from the symptoms you describe. If so, its an engine re-build I'm afriad.

Complete supposition though and the car should be taken to an expert for a full diagnosis!! You never know, might be something less serious!

Best of luck!

Ns04

Doomly

A bit of white at first mate, mainly blueish now. Intersting you say the map sensor as when first got the car a year ago had slight pauses in boost when putting my foot down. (I prevoiusly owned a Leon Cupra and the mass air flow meter went on that, Same thingish I assume?). When the engine went I had just put normal crappy unleaded in it and I normally always use optimax or BP ultimate! not sure if that would of made any difference though!!!

APIDavid

iTrader: (4)

Doomly , tough luck mate, call me if I can help you.

We tell customers that BP is a no-no in an Impreza [ waits for several posts to follow telling me what an idiot I am ]

Imprezas run much better on Optimax or even Tesco Super. Even UK cars, I know they are supposed to be able to run on regular fuel, but with a dodgy MAF [ 99 /2001 GC8 cars generally ] then playing Russian roulette with fuels is a poor idea.

Hard fast runs down motorways using boost at higher revs creates intercooler heat soak which will change the Fuel / air ratio yet again and a loud pop is not far away.

David APi Engines / APi impreza
www.apiengines.com

Graz

Sorry to hear it Classic hallmarks of a failing MAF sensor i'm afraid (MY99/00 with weak MAF especially bad) Sounds like you got some bad detonation during your fast run and it's trashed the big end bearings or blown a piston. Without any additional instrumentation I would change the sensor every 1-2 years for peace of mind. Knocklink may have saved your engine.

Do yourself a favour and get in touch with API for a rebuild (and a new MAF). So many recommendations on here, if I needed a rebuild that's where I'd go.

Shark Man

Does sound like a melted piston. Compression check will soon show that up.

Usually casued by a sensor fault or dodgy mods combined with hard use.

Your one of many to have suffered this.

Bottom end may still be salavage. Although detonation does overload bearings so you maybe looking at new bearing shells and pistons at the very least, although the crank will prbably have to be replaced if it has worn beyond tolerance (don't regrind - false economy).

New_scooby_04

iTrader: (4)

LOL Anyone thinking of calling David an idiot might want to bare in mind that my MY99 (with engine mods from APi, btw) was recently mapped in ambient temps of 30-32 to circa 320 bhp (bare in mind the mapping process involves some "higher" speed runs) No Knocklink activity whatsoever that I was aware of and no aborted runs at the request of my mapper, a certain Mr Bob Rawle!

My fuel - Optimax....... Co-incidnece???

Oh and when I asked the Bob about BP ultimate, he said it was the worst SUL he'd seen for the Impreza.

To the poster, looks increasingly like you've been a victim of the MY99s nototiously weak MAF sensor. If so, condolences. Easy to be wise after the event, but any fluctuations in a Classic's idle or hesitation at about 4k rpm should be treated with extreme suspicion and the car driven off boost until it's investigated. At least you now know for next time. I'd also recomend getting a Knocklink installed when you get your rebuild done- it'll warn you if detonation occurs.

All the best.

Ns04

Doomly

Thanks for the replys people.

Piston number two has gone, scorched the cylinder and cams. Had a subaru specalist near me look at it. I've been quoted 3400 ish for replacement bottom end from subaru with new uprated clutch re-conditioned fly wheel and cambelt/tensioners! with 12 months/12 thousand miles warranty!! Or 4200 ish with STi cams etc forged pistons better fly wheel but only 6months warranty/6 thousand miles. not sure what to go for!

Obviously the sti bottom ends going to be better but only 6 months warrantys worrying me. But I'm going to be worried bout a standard bottom end going again. Although from what your all saying its more my maff sensor. Would a re-map cure this?/ Any more opinions would be great. I love my scooby but not to good on how it all works. .

Neilo

certainly dont pay that much!! call API and they will sort you out with a much better price that that.

Aztec Performance Ltd

iTrader: (234)

Find out how much it would be without the flywheel+clutch.

Do APi warrantee theirs?

briforbes

http://www.importcarparts.co.uk/part...ype=&partsKey=

The Chief

Er how fast were you going down the M3 exactly??? I had my bottom end go after a high speed sunstained run (which scoobs dont like apparently) notice the word sustained!!!

Also BP is crap - sorry but it is - all the decent mappers will tell you the same, Bob Rawle says he'd wouldn't put it in his lawnmower - never mind a Subaru - in future stick Optimax if possible, if you have to put any other 97Ron in just dont hammer it as much and certainly dont maintain high boost in the upper gears (Andy F told me this)

mate its a pain in the a**e and it looks like its gonna cost you.

Davids a little expensive but he knows his stuff

New_scooby_04

iTrader: (4)

I reckon APi would be able to do it cheaper than that!I believe they also collect the car from anywhere in the UK too....although I may be mistaken on this.

Det caused by a dodgy Maf would kill an engine with STi internals too mate. But they woud be a good upgrade if you think you're going to want more power at some point, better to do it now than change your mind later. I'd consider a knocklink installed on your new engine to monitor for things like a filing maf, the only other thing you can do is just be aware of and resond quickly to the signs of a failing MAf that you know only too well now.

Phone David and ask for advice and a quote.

All the best,
Ns04

The Chief

I had an STi bottom end fitted to mine - but had the standard heads fitted back on -

It should not cost you anywhere near that, shop around a bit mate?

StudentScooby

Try scoobyclinic for a price

scoobyDAZZA

i use BP all the time



























in my lorry

Doomly

Thanks for the input. My mates think thats expensive to! The problem I have is its in his garage with no engine in it, he needed to strip it to find exactly what the fault is.

bob5 - he's charging me 530ish plus vat for the clutch and fly wheel both uprated. So thats about 2800 for replacement or 3600 for the upgrade. he has now offered me 12months warranty on both.

I assumed it would cost me 2500 at least to re-build the orignal or up to 3500 for a new block from subaru uk!! My problem is this is all new to me, never had or thought I would get a major prob like this!!

Doomly

The chief- I wasn't hanging about, but was accelerating to speed not sat at a high speed