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Exhaust noise

Posted: Sun Sep 24, 2006 6:46 pm
by JdeeK22
My car has a 57mm exhaust system wich souds good until the turbo kicks in.. The 'blowing' sound from the internal wastegate starts at around 3000rpm, growing louder up the rev range and eventually becomes unbearable inside the car at about 6000rpm! The noise comes straight out of the exhaust. At first I thought it was the turbo but the turbo is brand new! Anybody know what the problem might be and what can I do 2 make the sound go away?

Posted: Sun Sep 24, 2006 8:42 pm
by ChemCool
Is it a 200sx S13? Assume affirmative. As you will notice from the rest of the forum, a lot can go wrong. Let me try something. You say the waste gate starts the noise, but the sounds come from out of the exhaust??
What about it is neither the wastegate nor the turbo but rather manifold gasket. Leaking gaskets can make the same noise or high pitch whistle sounds like turbos and alike. Tell us more about the car. When last was the manifold gaskets been replaced, and were it replaced and fitted properly? It can lso bee the gaskets between exh manifold and turbo or gasket between turbo and down pipe. While the car is idling. Listen closely to the exhaust manifold. Let somebody else assist by reving the engine. Any leaks from exhaust manifold can be picked up. I used dishwasher soap sprayed on to the manifold fittings to look for leaks. Remember the car is then under no load and therfore you wont here the high pitches, but rather tractor diesel type of sounds???

Posted: Sun Sep 24, 2006 8:57 pm
by Daniel
I agree with freddie. That is most probably blowing exaust gaskets

Posted: Mon Sep 25, 2006 12:42 pm
by JdeeK22
Yup, the car is a 200SX (S13)..I bought the car about 2 months ago and the high pitch noise was there ever since I got it. Shortly after I recieved the car, the gasket between the manifold and turbo blew.. Only then could you hear the puffing sound from the manifold while reving the engine. I then had the gasket replaced, pretty sure it was done propperly, but the high pitch noise was still there! (puffing sound was gone though) I then replaced the oil feed line wich had cracked, and while I was at it, replaced ALL the other gaskets on the exhaust side (between head and manifold; between turbo and downpipe). Again done propperly using firegum on all gaskets. And yes, the high pitch noise was still there! I have drivin the car with all the windows down to determin where the noise is coming from and it is defenitely coming from the exhaust with no noise coming from the engine bay.. The previous owner told me that he had broken an oil ring on 1 piston wich caused alot of oil to go down the exhaust. The engine has been completely redone since but the exhaust was left as it is now.. do you think the oil in the exhaust might have something to do with the noise?

Posted: Mon Sep 25, 2006 3:49 pm
by ChemCool
I am going to tell you something you wont like. Right now my turbo, manifold and downpipe are lying outside next to the car. Not for the first time, most probably fifth time in a short period. Replaced gaskets and also said task well done. Eventually I found another leak from the gaskets.
Tomorrow I will buy a brand new set of manifold gaskets again, just to refit them properly again. Some guys advice the manifold to be skeemed.
At least make sure the surfaces are clean. I am trying to kill a noise sounds like turbo, but it is not.Where is your noise coming from? Front of car or to the rear? Oil in the pipe? I dont think so-would not know.Remember under load it will make a different noise because of leaking gaskets. My cars noise starts on beginning of boost , dissapears and starts again intermitantly. Hope to kill this with new gaskets fitted??? I must say I am not impressed with the fire gum. It only seals on the outsides, and all the rests gets pushed out away from the flat areas. Dont know if that is ok?

Posted: Mon Sep 25, 2006 7:44 pm
by JdeeK22
The noise defenitely comes from the rear of the car.. Straight out of the tailpipe. It also starts in beginning of boost, but does not stop. It just gets louder up the rev range and also gets louder as I go up the gears, and is at its worst at around 160 km/h in fifth gear. It litarally hurts your ears! But thanx 4 the advice! The gasket between the turbo and manifold just blew again this weekend. So I'll replace all the gaskets again and this time have the manifold skeemed. I hope the sound goes away this time, will let you know as soon as i'm done.. In the mean time if you have any other suggestions please let me know!

Posted: Mon Sep 25, 2006 8:57 pm
by ChemCool
Must be honest, from the back of the pipe? No dont know at all. Would like to know once the problem is solved.

Posted: Tue Sep 26, 2006 8:18 am
by WooHaa
If you have a hole in the back box that might cause a similiar noise. Have the entire exhaust system checked for holes & cracks.
Do you have the original system in place or is it a custom exhaust?

Posted: Tue Sep 26, 2006 9:28 am
by Jay_boy
need more info!! is it a wistling noise or more of a blowing noise????? :? cos if its a wistling noise not to sound all knowing but check your diff oil or gearbox oil!! but from what i have read it sounds like your diff!! :wink: look dont kap a stress im not saying it is but that is my oppinion to you :wink: if its a blowing noise its propebly the zorst thats got a hole ir crack!! its gona be a round of elimination??

Posted: Tue Sep 26, 2006 9:36 am
by Jay_boy
shoot!!! forgot to ask you?? you said at 160 its unbareble, is that under boost or just from driving??? lets say your crusing at 160 and you put your car in nutral and just let her free run, is the noise still there??

Posted: Tue Sep 26, 2006 12:24 pm
by widowmaker
another thing is the release bearing on the clutch - my other sx had a whistling whine - but only when in gear, so check if you rev without going forward. (or take out of gear at 160...) sound still there when at same revs, my money is on the turbo (especially coming from the zorst)

you sound like you have had the gaskets replaced before. I am thinking that you might have bent close those little oil supply pipes going to your turb. very dangerous - the big T needs all the oil it can get, so not enough oil can also make the bearings whine - and the sound has nowhere to go but out the zorst! It is very easy to bend those little sh!ts close when removing and replacing, so EVERYONE PLEASE check your lines!!!

Posted: Tue Sep 26, 2006 1:53 pm
by ChemCool
Agree! Easy way to check if oil feed correctly is to remove the oil pipe feeding back into the oil sump. Remove and crank engine. If oil runs through, perfect.

Posted: Tue Sep 26, 2006 9:33 pm
by JdeeK22
Definately a blowing noise and not a mechanical whine..very sure it's from the exhaust! It's only there when I put my foot down and only under boost. As soon as I close the throttle the noise is gone, regardless of wich gear i'm in or what speed i'm doing. The exhaust is a custum 57mm piece..

Posted: Tue Sep 26, 2006 9:38 pm
by JdeeK22
Also, I checked the oil feed to the turbo and it's fine..It's brand new, replaced it about a week ago.

Posted: Wed Sep 27, 2006 6:37 am
by Jay_boy
Good to hear!! well then im afraid it must be your zorst!! ok this is not recomended but start your car and let her idle then take your hand and cover the zorst tip completely listen for any blowing noises even get someone to help you?? :wink: if its got a hole you will hear it!! hope it works for you!! :wink: