Wastegate question

[fastfive0]

How can I tell if my stock wastegate is bad? I have been seeing less and less boost in the past two days. It was set at 15 psi and now I cannot spool past 10psi. I also have a whistling noise from under the hood and only when it goes into boost around 5 psi.

 

[Slowboy]

Where are you at in Pa? If close you could swing by and we can see whats up. Actuators do not go bad very often. May be a leaky IC pipe or the cronic cracked 1st gen manifold.

Mike Huml
www.slowboyracing.com

 

[fastfive0]

Im in the wilkes-barre/scranton area..........yeah the other side of the state!! Can I take off my heat shield and be able to see if its a cracked manifold? Would that keep my boost down? And whistle? This noise is not the normal boost spooling up noise it is more of a bad bearing in your alternator type noise.

 

[clarkscap]

This is exactly what I was after. Should I be able to move the acuator by hand? I think mine is stuck closed. I can unhook it from the flapper and the flapper moves, but I can't get the acuator to move. I'm getting 12-13 psi boost @ 4800 and I know stock is not more than 11 (on the stock guage).Also how much negative boost should I get when off the throtle, mine goes to the bottom.

Thanx guys,

 

[Newlogics]

with waistgate stuck close you'd be building boost in excess of 20psi.
(If you really want to see it, block the actuatore vacuum line (bend it and zip-tie) However, don't give is full throttle, because you can ruin your engine, boost jumps really fast that way.

Most likely problem - boost leak. Usually pipe joints. Also, often injector insulators go bad and let the air out.

 

[04DrBlur]

Well you probably have cracks around the wastgate flapper in the O2 housing and that is where your boost is bleeding off. If it were intercooler pipes your car would not build boost at all it would stumble and run like total sh--! Cracks in the manifold are also a culprit but you wont find them unless you take it off. Buy a 95+manifold and get it ported out. you will be happier anyway.

 

[04DrBlur]

Im sorry the cracks in the wastegate flapper are on the exhaust housing of the turbo....

 

[fastfive0]

What is this injector leak you speak of? I thought that I might have heard some whistling coming from the middle of the intak at idle but could not trace it to any hose and I checked them all. But there is deffinately a whine from the turbo. if the manifold is cracked would that limit my boost? I mean i can build 10psi and it will hold it there rock steady.