Hello, Everyone.
my car just lost boost from 21psi to 7 while accelerating. It will not go above 7 anymore.
Suggestions?

 

The obvious first - boost leak - check all your hoses/connections.

 

thanks. I don't know if the leak is large would it still build any boost?

 

Were you accelerating hard when it happened? Did you hear a "pop" ?
Any check engine lights come on?

As indicated, usually a leak. Places to check is Y-Pipe to IC's, Y-Pipe to throttle body, Lower hose from cool side turbo to IC's, or even recirculating valve tubes...Those are the most obvious..

DC

 

Actually, I had just shifted to 5th and at 137mph, heavy power loss . No "pop", but the exhaust was screaming . It will build boost, not beyond 7psi. I guess I'll find out in a couple of days when it goes to the shop.

 

+1

This happened to me the other day during a spirited drive. The Y pipe popped off of the throttle body.
Simple 5 min fix.

1. Loosen hose calmp
2. Push Y pipe back in to boot
3. Tighten hose clamp

 

Just checked, no visible problems. shop tomorrow

Thank you all

 

Report back what you find out...as it will help others, and help us all better Dx issues for members...

Good luck...I hope it is nothing serious.

As I was thinking about it, I was also wondering if one or both of the VTG actuator rods came loose or stuck? That may have these symptoms as well...

DC

 

Today, after the car rested, resumed normal operations.
I have no idea what's happening. Next week it will be at the shop

 

Welcome to the not-so wonderful-world of "limp mode". If it's not a boost leak there is some other problem that the ECU detected and put the car into limp mode (cut boost and probably a bunch of other stuff) to save itself. When you "rebooted", ie restarted the car, it reset but will strike again if similar circumstances present. It could be any number (as in dozens) of things. I assume you were on a track at 138 mph so it could be heat related, air fuel issues, a failing sensor, motor issues, exhaust pressures, etc. etc.

You should pull the diagnostic trouble codes from the OBD2 port if you know how to use them and if you want to get a head start on your mechanic. Sometimes these things are very easy to diagnose and fix: sometimes not so much. Let us know how things go. GL

 

Thanks, I'll find out what happened

 

I know this is old thread, but I would like to know what was the issue.