Bad wastegate??

[Manchild]

my 1987 gn is all stock with 20,500 miles on it. it was off
the road for 5 years. had no problems untill recently. when
I punch the gas, pedal to the floor, i hear a loud popping
noise and my car loses power. my turbo gage (stock)
max's out or red lines.....the engine seems to shake ..
I took it to a mechanic, and he is not familiar with turbo's.
he did mention that it may be a bad wastegate....what
are the symptoms of a bad wastegate???
any help will be much appreciated!!
thanks

 

[ES1]

Does this only happen when you are into boost?
If so, sounds like you may have a vaccum line off or split and you are overboosting.
Check the line from the wastegate solenoid (on the passenger valve cover) to the wastegate acuator and turbo. The line from the wastegate solenoid goes into a Y connector.
Make sure it is installed correctly after you look at it.
Zip tie all lines.
If that one is ok, look at the line that runs from the MAP sensor.
It is located on the passenger fender and is a hard line. I think it runs over to a connector at the end of the manifold.
If the car runs bad when not into boost, I would look at the MAF sensor.

 

[2QUIK6]

A faulty WG solenoid will cause overboost as well, the little red tipped sensor on the passenger valve cover. But as stated above, check all the vac lines first for any splits/ cracks. The vac line should go from the solenoid, to a "Y", the straight side of the "Y" should go to the compressor housing, and the branched off side of the "Y" should go down below to the WG actuator.

Don't hammer it too hard when testing again, that popping could be Knock if its a sharp sounding "Tick" sound and that will kill your rod/crank bearings or blow a head gasket, and loosing power because of timing being removed. If its a muffled pop, like a backfire thru the intake, then most likely your problem is coil pack / ignition module related, or ground strap not connected behind the heads to the firewall.

 

[Nick Micale]

You need to find someone that is familiar with the '86-7 Buick turbo motor, not just a "turbo" mechanic.

If you would go back to to your profile when you registered, you can list your location. This would help you find local board members that may be willing to help you?

 

[Manchild]

thanks for your help.

 

[Nick Micale]

Lots of good turbo Buick guys in the Tampa area, am sure you will hear from a few of them, good luck.