Its 20 degrees here as I left work tonite. I did not see this issue this morning but my truck sits in a garage all night.
I let my truck warm up for abot 5-10 minutes before leaving. I had my boost controller set to low boost (5-6 psi), I pulled out and at part throttle I saw it zip right up to about 8psi+ FAST!!
I did not even want to see what it would do set to high which I have set to 8.5psi right now.
Could the cold weather and the fact that it sat outside in this weather all day cause this? Is the wastegate diaphram cold and unflexable at these temps?
Kinda scary considering the fact that its only the middle of November and I have about 5 more months of this type of cold weather to go.
Is there that much more dense air at these temps. More power is good but DAMMM!!!
What are your thoughts?

 

If you take your wastegate apart you will find that it has some water in it. I have had mine apart twice and there was some water in it both times. There could also be water in the reference tube from the compressor housing to the wastegate. It sounds to me like the water in the reference line has frozen and the waste gate is not getting a proper signal if it is getting one at all. You might want to clean it out and keep an eye on it when temps are below 32*F.

Thanks for the heads up because I have not had to deal with freezing conditions yet. Maybe that tube needs a little drink of anti-freeze to get it through the winter months. Once the water is in there I don't think it can get out unless you take the tube off. Being under the truck the tube will probably never get warm enough to thaw out on its own. I don't think a small amout of green in that tube will hurt anything and it should keep it from freezing up.

 

This was a cold weather technical bulletin from STS. Right on with Mort's post.

"There have also been some instances where condensation freezes in the exhaust system during extreme cold weather. After start-up, this frozen water melts and flows down into the wastegate body as it is exiting the tail-pipe. This water then can refreeze in the wastegate housing preventing the wastegate from opening and controlling the boost level. Caution must be used during extreme cold weather to make sure that the exhaust system, including the wastegate, is up to temperature before attempting boosted driving. It is also important to always monitor the boost levels on your boost gauge to make sure that any over-boost condition is brought under control before engine damage can occur.

If you are concerned about the possibility of the wastegate freezing in extreme cold weather, the wastegate valve seat (ring at wastegate inlet) can be removed to allow a small amount of exhaust to continually bypass through the wastegate to help prevent ice buildup within the wastegate body. Removing the wastegate valve seat should not change the vehicle’s operating boost level, however, it will increase turbo lag by approximately 500 rpm."

 

Mort and Rockhugger thanks for the replies. Makes sense to me.
Hopefully I'll be able to check my wastegate at work today inside the building.
Its unseasonably cold here, about 20 degrees again this morning.
I want to see if there is ice in there, and if any is in my reference lines.
Never got any type of bulliten from STS I wonder if they have my correct
e-mail address??
I'll have to mail Dave South and get in the loop I guess.