Weird boost leak question...

[DynamicGN]

lets see if I can explain this...I either have a boost leak or the turbo isnt producing enough boost...the boost is turned all the way up on the wastegate, and I am only getting to 14 pounds, and not very quick either. I checked all the hoses, all good. I took the downpipe off to look at the turbo blades and noticed that the bolt that is part of the fins is chipped. So basically it's not a perfect hexagon, if that makes sense. I wish I can take a picture, but I don't have a camera right now. If no one understands I'll see if I can take a pic. Let me know if this may be my problem.

 

[bison]

Make sure your wastegate arm isnt stuck open. If its got that big of a boost leak you will hear it while driving.

 

[DynamicGN]

turbo doesnt whistle like it used to....how do i check the wastegate?...the puck in the DP swivels fine.

 

[DynamicGN]

Should I disconnect the hose from the actuator and plug it, then see if I get more than 14 pounds?

 

[bison]

Doy you have a cat converter on the car? Maybe you have an exhaust restriciton.

 

[DynamicGN]

No all open... THDP, ATR SS no cat, dump is closed

 

[bison]

Disconnect the air inlet and see if the compressor spins freely.

 

[DynamicGN]

Will do, might have to do that tomorrow. Thanks for the help, I'll let you know.

 

[ijames]

The turbine nut often has a bevel machined into it. If you have had the wastegate hoses off, this is the classic symptom of having the y pointed wrong. The leg with the restrictor orifice goes to the turbo compressor fitting, not the solenoid or wastegate. Also, make sure that the second port on the solenoid is open, not plugged or capped.

 

[84BuickGNYorkPA]

The odd looking bolt is that way because of balance grinding. As far as low/slow boost, I would check the compression of the cylinders, after checking/replacing the vacuum lines, and like mentioned above the routing of the vacuum lines, has to be right. Also the exhaust headers are known to crack, and that won't help any turbo spool fast. If you do the compression test it's a 5/8" deep well socket and put a swivel right on the deep well to get the plugs out. From my exsperience at Jack Cotton's the very first thing they do after a visual of the lines is a compression test. This will tell you the general health of the motors ability to pump air(power). Good luck and keep us posted on your progress..... oh by the way, I had the same problem with my 84 hot air motor and it was low compression in #3 cylinder, that's when I bailed on the motor and got a 87 installed.

 

[DynamicGN]

Ok guys I think I found the problem...I started with the easy stuff first. Checked the vacuum hoses, and checked to make sure everything was ok with the y-fitting, everything checked out fine. I checked the inlet side of the turbo and the compressor spins freely. Then I unplugged the vacuum hose to the actuator and plugged it. I took the car for a spin and slowly got on it, the boost quickly jumped to 26 pounds out of no where, of course I quickly let off. So does this mean I need a new wastegate, or is there a way to fix it? If I need a new one, is there a special one to get as in high performance, besides the external type ones where I need a new DP? Thanks for all your help guys, I learn as I go.

 

[84BuickGNYorkPA]

Can you take a picture of the vacuum lines hooked up to the wastegate selonoid, so we can take a look at them? Your turbo is ok
Chuck

 

[DynamicGN]

I guess look at "3361" first for perspective. These hoses were installed by Cal like 4 years ago, he basically used the same y-fitting but installed new hoses. I snipped off the tie wraps when I did the test, but the hoses are normally tie wrapped. It was kinda hard to take these pics as the actuator is in a tight spot. Poor pics, but I hope they help.

 

[84BuickGNYorkPA]

pic 3361 looks right, the "Y" appears to be correct. The compressor side of the turbo, line goes into the leg with the small reducer.

 

[DynamicGN]

Perfect, so which actuator should I buy, and where do I get it...should I just call precision for the same one, or is there some other thing I don't know about?

 

[84BuickGNYorkPA]

Take a air pump and recreate a boost situation or go to a service station and but a little pressure in the line that goes from the compressor to make sure that the actuator doesn't work, of course I would have the motor off to test this. You will need to unhook the line temporary to test it, be sure to hook it back up when you are done. Or go buy a couple of feet of vacuum line and rig something up to get pressure to that y connector, be sure to attach the vacuum line to the side of the "Y" that the compressor line is on. That's what I would do .....