Bov or Wastegate? Please Help! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

obsolete · 03-19-2009, 09:54 AM

So, all of a sudden driving yesterday, i was not able to build boost. It drives perfectly fine with no hesitation or stumble. just does not get the boost and power. I have a greddy RS and when i would rev it at idle, it would usually let off with compressor surge sound, but now all it does is give me a squeal like air leaking. i tried loosening and tightening all the way and no surge or letting off sound. my idle is fine minus a tiny bog/stutter every so often. My question is what are the symptoms of bad BOV? Do you think it's busted or my WG is stuck open? How do i check if the wg is functioning correctly?

zenki.life · 03-19-2009, 10:06 AM

yea my only gues(since im not a licensed mechanic lol) is that you have a leak somewhere. it would explain why you dont boost.

vortxxe · 03-19-2009, 10:46 AM

The chances of your wastegate being stuck open are pretty slim, it doesnt happen too often.

Most likely culprit is a boost leak. Check all your couplings (check if they are secure, and also inspect them for cracks or holes)... and then double check them to be sure.

To check your BOV, put your hand infront of it and rev your engine up aggressively (to build a bit of boost). The BOV should not allow any air to escape until you let off the throttle, at which point it should open and let out some air.

Sileighty_85 · 03-19-2009, 12:00 PM

its not your BOV

if the BOV was opening underboost the engine will hit a brick wall
because it relaseing all the metered air

if you have an exhaust leak at the turbo will will cause this, or if the turbo is blown

drifter_for_life06 · 03-19-2009, 12:07 PM

^^^^wat he said. I have similar problem but i KNOW FOR A FACT its an exhaust leak at the manifold->turbo gasket. I can hear the exhaust leak loud as shit thats how I know.

obsolete · 03-19-2009, 12:23 PM

say the turbo is blown, but BOV is ok, shouldn't the BOV still do it's function at idle? like build and release air?

jackal264 · 03-19-2009, 12:30 PM

the bov would never open b/c there is no pressure to release b/c the turbo is not making any boost. a blown turbo would be really easy to spot though. you would have a lot of smoke comming out of the exhaust. however i have seen a wastgate get stuck open and that would cause similar issues.

pinkarrowsnow · 03-19-2009, 12:37 PM

Torn coupler probably look at all of them. If you have a boost gauge whats your vac now and what was it before. Maybe a vac line popped off the wastegate. Give more info def sounds like a vac leak.

obsolete · 03-19-2009, 12:40 PM

come to think of it, i do have a lot of noise when I start to get going. whining and metal rubbing. I thought it might be noise from the trans. I'll have to check that later. I didn't notice any smoke coming out the exhaust. would it be at idle or while driving? or all the time? It just happened after I set the timing. I didn't touch anything else. I have an electronic gauge that doesn't read vac. wack.

Sileighty_85 · 03-19-2009, 01:18 PM

Quote:

Originally Posted by pinkarrowsnow

Torn coupler probably look at all of them. If you have a boost gauge whats your vac now and what was it before. Maybe a vac line popped off the wastegate. Give more info def sounds like a vac leak.

Torn couple would would have the same symptoms as if the BOV was leaking.
If the Vac line popped off the W/G it would over boost

If your hearing a Grinding noise durring boost then the Compressor wheel is making contact on the Turbo housing.

Pull off the turbos intake pipe and check for shaft play on the compressor wheel

it it possible for the bearings to wear out and and not leak oil

pinkarrowsnow · 03-19-2009, 01:28 PM

Quote:

Originally Posted by Sileighty_85

Torn couple would would have the same symptoms as if the BOV was leaking.
If the Vac line popped off the W/G it would over boost

If your hearing a Grinding noise durring boost then the Compressor wheel is making contact on the Turbo housing.

Pull off the turbos intake pipe and check for shaft play on the compressor wheel

it it possible for the bearings to wear out and and not leak oil

Yeah what am I saying about the wastegate line popping off it happened to me haha i hit like 40psi duh i didnt think straight.

smelly240 · 03-19-2009, 01:30 PM

IF HIS GREDDY RS WAS LEAKING AND RECIRCED - ITS NOT GONNA MAKE BOOST *OR* DRIVE LIKE A TORN COUPLER...

IVE SEEN THE TURBINE WHEEL BREAK OFF A T25 MORE THAN ONCE (TWICE ACTUALLY

)

IF IT DOESNT GO NUTTY RICH - A COUPLER ISNT TORN

no clue why thats all caps - but im not retyping it.

obsolete · 03-19-2009, 02:01 PM

Well i did some more searching and it sounds like the gasket from manifold to turbo is a high possibility. gonna check that as well as the bov for leaks. my Greddy is not recirc-ed. fix one thing and something else goes wrong. this is aggravating

opponheimer · 03-19-2009, 03:25 PM

If its not building boost your wastegate actuator must have popped off the flapper arm. That is the only way it would run right and not build boost and the turbo not being blown... There is your solution.

Use safety wire to attach the thing.

Other than that you've given no info on motor, turbo setup, whatever... a motor with a bad turbo inlet gasket would still be able to build some boost and you'd hear it/feel it on a cold motor if you put your hand around the flange..

obsolete · 03-19-2009, 04:40 PM

Quote:

Originally Posted by opponheimer

If its not building boost your wastegate actuator must have popped off the flapper arm. That is the only way it would run right and not build boost and the turbo not being blown... There is your solution.

Use safety wire to attach the thing.

Other than that you've given no info on motor, turbo setup, whatever... a motor with a bad turbo inlet gasket would still be able to build some boost and you'd hear it/feel it on a cold motor if you put your hand around the flange..

That is exactly correct! I just got home and took a look. Stupid me.

http://i691.photobucket.com/albums/v.../wastegate.jpg

How do I keep that attached? what is a safety wire?

Thanks all for your quick responses. learned a lot.

opponheimer · 03-19-2009, 05:43 PM

go to home depot, its in the sign section... its wire you just loop in through the hole on the flapperthen wrap it around the actuator rod and then twist it off, get creative.. itll hold.

or you can just get a new c-clip if u can find one that fits

Ceepo · 03-19-2009, 07:00 PM

Weld it closed

opponheimer · 03-19-2009, 08:14 PM

Quote:

Originally Posted by Ceepo

Weld it closed

lol.. he won't have trouble building boost then

03-19-2009, 09:54 AM	#1
obsolete Zilvia Addict Join Date: Aug 2003 Location: NJ Age: 45 Posts: 717 Trader Rating: (8) Feedback Score: 8 reviews	Bov or Wastegate? Please Help! So, all of a sudden driving yesterday, i was not able to build boost. It drives perfectly fine with no hesitation or stumble. just does not get the boost and power. I have a greddy RS and when i would rev it at idle, it would usually let off with compressor surge sound, but now all it does is give me a squeal like air leaking. i tried loosening and tightening all the way and no surge or letting off sound. my idle is fine minus a tiny bog/stutter every so often. My question is what are the symptoms of bad BOV? Do you think it's busted or my WG is stuck open? How do i check if the wg is functioning correctly?

03-19-2009, 12:00 PM	#4
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	its not your BOV if the BOV was opening underboost the engine will hit a brick wall because it relaseing all the metered air if you have an exhaust leak at the turbo will will cause this, or if the turbo is blown __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

03-19-2009, 12:07 PM	#5
drifter_for_life06 Zilvia Addict Join Date: Sep 2005 Location: New Freedom, PA Age: 36 Posts: 775 Trader Rating: (6) Feedback Score: 6 reviews	^^^^wat he said. I have similar problem but i KNOW FOR A FACT its an exhaust leak at the manifold->turbo gasket. I can hear the exhaust leak loud as shit thats how I know. __________________ RPS13: +.020" 2871r 264's AEM EMS http://enjukuracing.com/#_l_4s

03-19-2009, 12:37 PM	#8
pinkarrowsnow Zilvia Addict Join Date: Feb 2007 Location: NJ Posts: 639 Trader Rating: (2) Feedback Score: 2 reviews	Torn coupler probably look at all of them. If you have a boost gauge whats your vac now and what was it before. Maybe a vac line popped off the wastegate. Give more info def sounds like a vac leak. __________________ http://allies-drift.blogspot.com/

03-19-2009, 01:30 PM	#12
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 47 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	IF HIS GREDDY RS WAS LEAKING AND RECIRCED - ITS NOT GONNA MAKE BOOST OR DRIVE LIKE A TORN COUPLER... IVE SEEN THE TURBINE WHEEL BREAK OFF A T25 MORE THAN ONCE (TWICE ACTUALLY ) IF IT DOESNT GO NUTTY RICH - A COUPLER ISNT TORN no clue why thats all caps - but im not retyping it. __________________ HREs on a S13 - check, 6262 - check, Girlfriend.... - nope

03-19-2009, 10:46 AM	#3
vortxxe Join Date: Mar 2007 Location: Comox, BC, Canada Age: 36 Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	The chances of your wastegate being stuck open are pretty slim, it doesnt happen too often. Most likely culprit is a boost leak. Check all your couplings (check if they are secure, and also inspect them for cracks or holes)... and then double check them to be sure. To check your BOV, put your hand infront of it and rev your engine up aggressively (to build a bit of boost). The BOV should not allow any air to escape until you let off the throttle, at which point it should open and let out some air.

03-19-2009, 12:23 PM	#6
obsolete Zilvia Addict Join Date: Aug 2003 Location: NJ Age: 45 Posts: 717 Trader Rating: (8) Feedback Score: 8 reviews	say the turbo is blown, but BOV is ok, shouldn't the BOV still do it's function at idle? like build and release air?

03-19-2009, 12:30 PM	#7
jackal264 Zilvia Junkie Join Date: Feb 2007 Location: vancouver, canada Age: 39 Posts: 360 Trader Rating: (1) Feedback Score: 1 reviews	the bov would never open b/c there is no pressure to release b/c the turbo is not making any boost. a blown turbo would be really easy to spot though. you would have a lot of smoke comming out of the exhaust. however i have seen a wastgate get stuck open and that would cause similar issues.

03-19-2009, 12:40 PM	#9
obsolete Zilvia Addict Join Date: Aug 2003 Location: NJ Age: 45 Posts: 717 Trader Rating: (8) Feedback Score: 8 reviews	come to think of it, i do have a lot of noise when I start to get going. whining and metal rubbing. I thought it might be noise from the trans. I'll have to check that later. I didn't notice any smoke coming out the exhaust. would it be at idle or while driving? or all the time? It just happened after I set the timing. I didn't touch anything else. I have an electronic gauge that doesn't read vac. wack.

03-19-2009, 02:01 PM	#13
obsolete Zilvia Addict Join Date: Aug 2003 Location: NJ Age: 45 Posts: 717 Trader Rating: (8) Feedback Score: 8 reviews	Well i did some more searching and it sounds like the gasket from manifold to turbo is a high possibility. gonna check that as well as the bov for leaks. my Greddy is not recirc-ed. fix one thing and something else goes wrong. this is aggravating

03-19-2009, 03:25 PM	#14
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	If its not building boost your wastegate actuator must have popped off the flapper arm. That is the only way it would run right and not build boost and the turbo not being blown... There is your solution. Use safety wire to attach the thing. Other than that you've given no info on motor, turbo setup, whatever... a motor with a bad turbo inlet gasket would still be able to build some boost and you'd hear it/feel it on a cold motor if you put your hand around the flange.. __________________ SR20 & RB20/25/26 in s13/s14 Wiring from $125 to $200.. Best prices EVER.

03-19-2009, 05:43 PM	#16
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	go to home depot, its in the sign section... its wire you just loop in through the hole on the flapperthen wrap it around the actuator rod and then twist it off, get creative.. itll hold. or you can just get a new c-clip if u can find one that fits __________________ SR20 & RB20/25/26 in s13/s14 Wiring from $125 to $200.. Best prices EVER.

03-19-2009, 07:00 PM	#17
Ceepo Nissanaholic! Join Date: Jan 2008 Location: Cedar City, Utah Posts: 2,007 Trader Rating: (9) Rides Gallery: Ceepo Feedback Score: 9 reviews	Weld it closed __________________ TW: http://zilvia.net/f/cars-sale/390459...d9s-coils.html