Is the flapper closed at idle? Or does the ECU only Close it as boost is needed and it stays open at idle? (Explain this later)


The car is suffering from the 2C57 code. I have pulled the downpipe and checked the flapper with my hand pump and it does have some play but when the flapper is closed it is not pulling open on the back side and I can feel no play when it's closed and i push around on the flapper with a screwdriver so I think the flapper/gate is fine. I also looked over and don't see any obvious boost leak causes. My scanner shows live data and I took it for a drive. It was very foggy so I couldn't get on it hard for long but a 3rd gear pull into the 4k rpm range it was only showing around 30 inches of mercury on the MAP reading (idle was 25) so that's only a few pounds of boost. I have always felt the car feels flat.

So about the top question. I got the car as a flood salvage and rebuilt it, and i have never driven a mini before but I'm not new to cars or turbos. This car has always felt flat to me, like no real spool up or turbo sound at all. So I'm thinking that maybe the water damaged the wastegate control solenoid and its not working to allow vacuum to the gate, so I was asking if it's to be close at idle because this one is not closed at idle.

my next steps are.

unhook vacuum line from gate and drive and watch the MAP and see if it's the same as last eve.

pull vacuum on the gate and hold it so i can take it for a drive to see if i can get a overboost code. I'm really thinking It will overboost. Then i will Check vacuum lines/ pump
if the pump pulls good vacuum and lines look fine i will look deeper into the boost solenoid. And if they check out
pull and check diverted valve. I'm thinking since what I have seen the boost controller solenoid sits fairly low in the chassis and the electronics got damaged from flood water.

 

The wastegate will only close when boost is requested.

If you are sure the wastegate is closing, check the diverter valve to make sure the diaphragm isn't torn. Also check all the boost tubes to make sure none are torn or loose.

 

Thanks. I will have to pull the valve shut and go for a drive and if that builds boost start looking into solenoid, lines, and diverter valve issues.

 

Be careful with that. Boost can build pretty quick. Do you have a mechanical boost gauge?

 

No. I have a electric gauge somewhere in the box laying around but the car doesn't have one installed. I wasn't going to go for a actual drive with it I was just going to go 100yrds or so to see if there is ant noticeable change. I lost my Bluetooth dongle to run the Torque app or I would use that instead of my code reader to log the MAP. I'm really thinking that the solenoid isn't working or the diverter valve isn't working.
speaking of the DV doesDVt normally open or closed? I guess the flood could have killed the electrical side of it also and it could be bleeding it all off?

 

I'm not sure the operation of the diverter valve, but it is electronically actuated. If the flood got that high, then its possible it has some stiction in it.

Before you go and drive with the wastegate tied closed, I would pull the diverter valve and inspect.

 

the water was over the dash so it was high enough to have caused a issue there.
I may even have enough hose that I can put a T and watch the vacuum applied on the wastegate while I go for a drive

 

Update.

I unhooked the vacuum line off the wastegate and connected some extra hose and my vacuum gauge. I went for a drive and it registered nothing, and the scan tool reading only hit around 30 inches of of mercury, with 25 being the base idle. I'm going to order the boost solenoid and since they are known to have issues and it probably got damaged also i'm just going to replace the diverter valve also.

 

After replacing the diverter valve and the boost solenoid (99% sure this is all that was needed since it wasn't passing vacuum to the gate) it's running with no low power mode and actually doesn't feel flat. 👍