after i replace my turbo inlet pipe if the hiss is still there

then it only leaves 1 other possible thing (dump valve leaking)

would it hurt anything if i blocked the dump valve holes with maskintape where it shoots air out on decelaration? just for 5 mins

reason is i think the dump valve might not be fully closing when i accelerate

so it would seal if i did above?.

 

 

what type of dv is it mate i had this on my old wrx with a bailys on,the piston kept sticking and making a loud hissing noise, just sprayed wd40 in it while reving it and it stopped straight away, hope this helps. if not just ignore me

 

i doubt masking tape would seal up the dv.

you need to try and seal up the inlet in to dv,and no if you did this then no harm would be done if it is for a short period just to test it.

 

I Replaced my DV with a piece of stainless bar.. did the job.. pluged the vacume line with a bolt! This was on a 1995 wrx..

 

its a double piston baileys dv26

and i will try the wd40 trick cheers

im dont fully understand the dump valve so if anyone has a pic of the pipes to block or join to test please post

all i have is 1 small pipe on top of dv and a big one at bottom going to intercooler thingy under scoop

cheers

i will try anything that wont hurt my car
many thanks

 

bbump

 

You want to block the pipe leading to the dump valve from the intercooler.

Masking tape wont stop a pressureised fart never mind 1bar of boost.

 

im not all that sure that blocking the dump valve is all that great a good idea. cant you just put the standard one back on for a bit or something else. i know when i was adjusting my dv and adding springs till i found the correct boost. when i put too many springs in and it failed to open then i got alot of engine bang noises that didnt sound healthy and it back fired alot. so i took one washer out and it ran fine.

 

i dont have original part as dv valve was on car when i bought it

and for fart man above i was thinking of just muffling sound to see if its quiter rather than blocking

 

where is the hissing noise coming from roughly?? can you tell side of engine or anything? i have a similar noise but its more a very high pict leaking air noise. randomly started one day. goes away when car is warmed up though.

 

the hissing can only be heard when driving it doesnt do it when stood

it sounds like a hover sucking when accelerating but rises with revs

its not the air filter sucking in air as its 10x louder

i was thinking of having a mate lay on engine while i drove it on a carpark to discover where it was coming from but i think its a bit risky so i will have to let it develop i think

 

my car did use to hiss when cold but thats normal from air filter

when warm it did disapear

but now does it all time and not from air filter

 

does it happen when under say 3000rpm or only when its higher. turbo wont kick in till around then so if its air filter it will happen all the time.

 

i would say it starts around 3000 rpm when turbo kicks in but it never did it before?