jason7579

I have just started hearing a whistling noise coming from my 2004 WRX. It happens in or out of gear and before and during boost (so shouldn't be the turbo?). Is audible from the drivers seat at from around 1500 rpm and increases and decreases with acceleration / revs.

Any ideas? My first thought is a leak from the exhaust system somewhere near the front (uppipe?).

https://www.youtube.com/watch?v=zGc2...ature=youtu.be

Thanks..

jason7579

So after a little investigation I have discovered that there is a lot of exhaust blowing from the downpipe somewhere. I can feel air escaping from approximately where the arrow below shows (in the same direction). I will be taking the downpipe off at the weekend for inspection, is this likely to be just a gasket needed or a new downpipe?


Any opinions, even pure guess work appreciated.

JDM_Stig

iTrader: (3)

down pipe gasket

jason7579

Thanks for the quick reply. That was my initial thought, but it feels as though it is blowing up from the heat shield towards the turbo/downpipe connection.


As I will be taking it all off anyway are there any recommended gaskets? Otherwise I will head to ECP and see what they have.

ScottyPPP

Try and use an OEM gasket. It could also be the pipe is split where it meets the flange.

jason7579

Thanks, I will have a look when I take it off and contact Subaru about getting an oem gasket.

ScottyPPP

ICP sell them online and they're pretty quick to deliver.

jason7579

Funnily enough after replying to your last message I had a little google search and ordered directly from ICP.


Now I just hope that the studs don't break, I will be taking everything apart tonight and liberally apply penetrating fluid every day until I actually remove it on Sunday. Is it worth running the engine and getting the turbo warm before attempting to remove or would that increase the possibility of stripping the threads?


Thanks very much for your advice.

ScottyPPP

I wouldn't bother running it, you'll just end up burning the crap out of your hands!

Just give them a spray, top 2 are a bolt and nut so they'll be fine. I doubt the studs will snap. Even if they do they're pretty easy to replace.

jason7579

Thanks.


Reminds me of a my recent MOT... the tester said he should fail it as its the only car that has given him instant blisters from touching the exhaust as he was taking out the emissions wand

jason7579

Finally got time to have a better look and the turbo to downpipe bolts came off beautifully. Unfortunately the same can't be said for the other end!!! I'll have to take it down to the local exhaust place to get it separated.

I'm fairly certain that the flange has split as mentioned above so it looks like new down pipe required. Does this look like the standard wrx down pipe?

​

Thanks

ScottyPPP

That's a standard downpipe.

JDM_Stig

iTrader: (3)

if you have the old gasket in your hand, you should see if it was blowing.

jason7579

Thanks.


I couldn't separate the downpipe and the midpipe so couldn't actually remove it enough to get the gasket out. However the gasket was crumbling as I tried to pull it away so it definitely needs replacing.


I think I will try to separate the mid and rear sections next and attempt to remove the downpipe and midsection together.

jason7579

One sheared bolt and a lot of swearing later and finally got it all removed, downpipe and midpipe had to come off as one piece though.


As you quite rightly pointed out the pipe is split where it meets the flange as per the picture below. A friend at work thinks its junk and not worth repairing, looking at the state of the flanges (deteriorating into rust) I am inclined to go with what he says.


I now need to replace both the down and midpipe and I would value any opinions on what to replace with. I'd like to keep it MOT legal so am thinking of trying to source a second hand prodrive sports cat downpipe with midpipe (catless?) or I have looked at possibly getting a new sports cat downpipe from Japspeed. My budget doesn't stretch to the likes of RCM or Cobb.


Thanks

ScottyPPP

PPP Sports cats pop up fairly often, they normally come with the 2nd decat pipe attached. I used one a few years ago. You had to get it crazy hot to pass emissions on the MOT. I've not had much experience of other sports cats. I ran a Japseed 3" to 2.5" decat downpipe for a while and it fitted well.

You might need a map if changing from the stock downpipe. I'm running fully decatted on mine with a 3" turbo back system. It's loud but I need the flow

jason7579

Thanks, I appreciate all the help, I am clueless with Turbo cars but am slowly learning!


With your post in mind I have narrowed it down to Japspeed and either the sports cat and get it nice and hot for the MOT or go full decat and just use chemical metal on my split one and swap it over come MOT time. Full decat will free up the cash to grab an sti uppipe at the same time so I won't have to worry about the performance losses from the ebay flexi that the previous owner installed.


My plans are nothing too major, I'm looking to get a nice safe increase in power and torque when I get it remapped, with the basics such as uprated panel filter and decent spark plugs.

ScottyPPP

I've got a set of STI headers for sale with a decat up pipe, along with a load of other stuff. Check the forsale section.