External Wastegate open at idle - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

army240 · 05-15-2009, 03:28 PM

Well, I finally started my engine, everything is fine, except one thing.

The wastegate is leaking exhaust gas! It's a Tial 44mm with a 12 psi spring I tried many vacuum line setup(Before throttle plate, after throttle plate, on the hot pipe, with the boost controler hooked, without the boost controler, with the top port open to the air, with the top port connected to the boost controler) and it still leak some exhaust gas! The dump tube is connected to the air, and it's annoying!

I tried to put some air pressure to the bottom port(like 15psi) to make it work, and the diaphragm is ok. I can hear the valve open and close. I applied some air pressure to the top port(to force it to be close) and it still leaking...

Any idea what I could do? I'm out of idea, lol!

Thanks a lot,

Frank

duffman1278 · 05-15-2009, 04:21 PM

The wastegate is suppose to be open at idle, thats one of its purposes. It's suppose to release some of the exhaust pressure during certain phases so that you're not over working your turbo.

Sileighty_85 · 05-16-2009, 12:47 AM

Quote:

Originally Posted by duffman1278

The wastegate is suppose to be open at idle, thats one of its purposes. It's suppose to release some of the exhaust pressure during certain phases so that you're not over working your turbo.

What???

Ive never heard of an External W/G opening at idle...
its on a 12lbs spring too. I dont know his setup but i dont think he making 12psi at idle

almost sounds like the spring is broken or maybe the valve is not seating correctly?

if you pull it off the Vac source does it still leak??

army240 · 05-16-2009, 01:39 AM

Yes it does leak even if I disconnect all the vacuum line, and no, a wastegate should not be open at idle!

I'll try my friend Synapse wastegate to see if it does the same, and if not, i'm gonna check the spring in it. I believe the spring is correct, because when I blow some air from an air gun, I can hear the valve open and close when I let the air go out of the wastegate. After that, I'll ask Tial to change my wastegate, it was brand new! N/S on issue happens sometime I believe!

Thanks a lot for you advice,
Frank

opponheimer · 05-16-2009, 05:56 AM

The valve stem could be coming in contact with the guide wall and catching/staying open... it happens with ssautochrome wastegates. The spring could also be wrong type or too short. Take the damn thing off and figure it out yourself by taking it apart

SR20JK · 05-16-2009, 11:15 AM

Quote:

Originally Posted by duffman1278

The wastegate is suppose to be open at idle, thats one of its purposes. It's suppose to release some of the exhaust pressure during certain phases so that you're not over working your turbo.

please dont spread wrong information.

orion::S14 · 05-16-2009, 03:03 PM

Are you missing the 'seat'...

If the valve moves freely, chances are...it's not sealing. It doesn't seal if it's missing the seat-->

Goes here:

???? - Brian

Z U L8R · 05-16-2009, 09:11 PM

i concur with orion

beat me to it

Dave

you also may have a piece of weld or debri caught in it and keeping the valve from closing all the way. best thing to do is take it off and examine

army240 · 05-16-2009, 10:49 PM

Ok thanks a lot guys! I found the problem, there was a dent in the valve seat! I really don't know how it as been damage... I replaced it, everything is fine!

Frank

05-15-2009, 03:28 PM	#1
army240 Zilvia Junkie Join Date: May 2008 Location: Quebec Age: 36 Posts: 306 Trader Rating: (1) Feedback Score: 1 reviews	External Wastegate open at idle Well, I finally started my engine, everything is fine, except one thing. The wastegate is leaking exhaust gas! It's a Tial 44mm with a 12 psi spring I tried many vacuum line setup(Before throttle plate, after throttle plate, on the hot pipe, with the boost controler hooked, without the boost controler, with the top port open to the air, with the top port connected to the boost controler) and it still leak some exhaust gas! The dump tube is connected to the air, and it's annoying! I tried to put some air pressure to the bottom port(like 15psi) to make it work, and the diaphragm is ok. I can hear the valve open and close. I applied some air pressure to the top port(to force it to be close) and it still leaking... Any idea what I could do? I'm out of idea, lol! Thanks a lot, Frank

05-15-2009, 04:21 PM	#2
duffman1278 Post Whore! Join Date: Apr 2007 Location: Covina Age: 33 Posts: 2,844 Trader Rating: (8) Rides Gallery: duffman1278 Feedback Score: 8 reviews	The wastegate is suppose to be open at idle, thats one of its purposes. It's suppose to release some of the exhaust pressure during certain phases so that you're not over working your turbo. __________________

05-16-2009, 05:56 AM	#5
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	The valve stem could be coming in contact with the guide wall and catching/staying open... it happens with ssautochrome wastegates. The spring could also be wrong type or too short. Take the damn thing off and figure it out yourself by taking it apart __________________ SR20 & RB20/25/26 in s13/s14 Wiring from $125 to $200.. Best prices EVER.

05-16-2009, 03:03 PM	#7
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,665 Trader Rating: (0) Feedback Score: 0 reviews	Are you missing the 'seat'... If the valve moves freely, chances are...it's not sealing. It doesn't seal if it's missing the seat--> Goes here: ???? - Brian __________________ www.KA24DEvelopment.com

05-16-2009, 09:11 PM	#8
Z U L8R Zilvia FREAK! Join Date: Jan 2007 Location: Georgia Age: 39 Posts: 1,194 Trader Rating: (0) Feedback Score: 0 reviews	i concur with orion beat me to it Dave you also may have a piece of weld or debri caught in it and keeping the valve from closing all the way. best thing to do is take it off and examine __________________ RB25 280z GT30/76R 441hp/381tq [email protected]

05-16-2009, 01:39 AM	#4
army240 Zilvia Junkie Join Date: May 2008 Location: Quebec Age: 36 Posts: 306 Trader Rating: (1) Feedback Score: 1 reviews	Yes it does leak even if I disconnect all the vacuum line, and no, a wastegate should not be open at idle! I'll try my friend Synapse wastegate to see if it does the same, and if not, i'm gonna check the spring in it. I believe the spring is correct, because when I blow some air from an air gun, I can hear the valve open and close when I let the air go out of the wastegate. After that, I'll ask Tial to change my wastegate, it was brand new! N/S on issue happens sometime I believe! Thanks a lot for you advice, Frank

05-16-2009, 10:49 PM	#9
army240 Zilvia Junkie Join Date: May 2008 Location: Quebec Age: 36 Posts: 306 Trader Rating: (1) Feedback Score: 1 reviews	Ok thanks a lot guys! I found the problem, there was a dent in the valve seat! I really don't know how it as been damage... I replaced it, everything is fine! Frank

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