strange noise......det?....cel?
 

just been driving my car....classic 98 sti type r with jdm sti 9 motor.
been running perfect since build,but tonight i heard a very strange noise which sounded almost like a metally,gritty sound from engine.almost fluttery.thought nothing of it,then i heard the sound again and started to worry,then i heard it blatenly and tickled the throttle like a feather as it threw a cel shortly after and i knew something wasnt right,before this all my driving was nice and steady as roads were icy....kepping revs low and cruising gently,i put it under a small amount of load in 5th gear(3 quarters throttle) a couple times.50-70mph ish.
my first thoughts are possible maf,it runs the orange lable maf.or maybe something to cause it not to run right,i turned engine off,had a look under bonnet with oil and water all fine,no visible problems,(although it was dark and my torch was not great).
i then had to get home so i started it back up,cel flicked on again,then went out but the initial firing up of engine didnt sound quite right?
almost like engine was not firing as strong or something.
i featherd it home and didnt exceed 3rpm,and stayed below 40mph.
it got home with no funny noises and no more cels........but now im worried!:facepalm:

any thoughts? what does det sound like?

no knocking whatsoever but im still very worried.:(

Det if you hear it with your ears when driving is extreme, but sounds like a loose nut or bolt rattling around in the engine.

Are you running an after-market ecu?

Graham

yes, apexi power fc.
it was definetely a noticeable sound,almost like there was a load of grit thrown up in the engine.:confused:

The CEL light should flash rapidly if set right on the Apexi. Did it flash, or just stay on?

it flashed up once and went out quickly .

It should have flashed 3-4 times for a preset length of time, evades me how long without looking at the default setting. I would get it checked if you think it may have been det.

Graham

im not even gonna start it as im s**tting myself.
its certainly not the noise of a failure as i know exactly what that sounds like,but i dont want to start it or drive it as im worried the dreaded knock will appear.

Did you have a look at the knock count on the commander? Mine is set to trigger the CEL at 30

cel should flash 9 times if knock exceeds 30....this didnt happen,i have not checked commander yet..

Hopefully it's not det then and it's something else

The sound you are describing sounds like det to me.

We used to call it "pinking".

update.....been fine for a few days,and the noise appeared again today during gentle driving,monitoring knock level and it was 38....something definetely wrong with it,but what? any ideas? engine still sounds fine but im very concerned as to wether i should be driving it or not?

Have you bought any different petrol ? or did you do a fill up before these noises started ? A bad batch of fuel can cause lots of probs .

i filled the tank the day before this first happened,got it from my usual shell garage,the noise is not nice when it happens and almost sounds like something has fell of the engine,dragged underneath and then the noise dissapears,it frightens the s**t out of me as i think my motor is about to fail.:cuckoo:

Its a question i always ask now after having several previous cars i have owned behaving badly after a refuel. If you have filled the tank you may have a few days more torture yet, get the car checked but dont spend any money until fuel is ruled out. Good luck.

Lob some NF in, if it goes away it's ****ty octane fuel :)

can bad fuel cause horrific scary mechanical noises?

its the same v power i always use from the same garage.

Not a genuine mechanical noise, no. Get a second opinion on the noise. Is it happening under load ? when Det would happen more, or at a certain rpm ?

If i thought my car was suffering with Det due to bad fuel i would whack in some octane booster just to cover the bad fuel issue.
Since refuelling have you thrashed the car, to cause any mechanical issues ?

Delivered in different batches ;) it's doesn't breed there :lol1: hence 'bad batch' :) try some NF as if it's sporadic it's more than likely fuel related rather than mechanical or the det would be more apparent more of the time :)

no,its only happened 3 times in the last week,not driven hard,can happen at any time,any rpms etc.just cruising at 30-40mph it can do it.

[QUOTE=madmarx;10471327]If i thought my car was suffering with Det due to bad fuel i would whack in some octane booster just to cover the bad fuel issue.
Since refuelling have you thrashed the car, to cause any mechanical issues ?[/QUOTE

no,only steady village driving.

surely if the fuel was a "bad batch" ,then it WOULD be doing it all the time?:wonder: