Is this Boost Possible?
12-10-2008, 10:12 PM
#32
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This thread is concerning me a bit....when I first took my potential car out it was doing the normal .7 .8 max boost tonight I hit 1 and 1.1 may have even hit 1.2 (a bit too excited to recall 
) I'm taking the car for it's PPI tomorrow so I will mention to the dealer. May go take the car for another spin tonight to see if it still does it. Other symptoms I experienced last time I had the car.....ABS/PSM light came on under hard driving on the highway pulled over restarted car and it went off....Car stalled on startup again after HARD driving....and....in the morning the next day after hard driving day before the car emitted a large amount of smoke for about 1 1/2 min's ...want to say it was a white smoke......any ideas?
) I'm taking the car for it's PPI tomorrow so I will mention to the dealer. May go take the car for another spin tonight to see if it still does it. Other symptoms I experienced last time I had the car.....ABS/PSM light came on under hard driving on the highway pulled over restarted car and it went off....Car stalled on startup again after HARD driving....and....in the morning the next day after hard driving day before the car emitted a large amount of smoke for about 1 1/2 min's ...want to say it was a white smoke......any ideas?
12-10-2008, 10:43 PM
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ok just got back from my test drive and the car hit 1.5 bars in 3rd gear WOT around 6000 RPM. So let's see what they find tomorrow....I will update the thread...thanks!
12-11-2008, 06:30 PM
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Had the PPI and computer check done today, computer showed failure: 01255 Boost pressure curve, upper value exceeded...guess that explaines hitting 1.5 bar. Also found a slight oil leak in rear of the engine. So looks like I'm onto my next car to check out.
12-12-2008, 09:16 PM
#35
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Luke... I pulled up the fault printouts for the faults you provided. P1250 (Boost Pressure Control Deviation - Above Limit) possibe fault causes as per workshop manule, bypass flaps incorrectly adjusted, or Turbocharger faulty. I would look into the incorrectly adjusted bypass flaps (waste gates) and discard the faulty turbo idea. The other fault, P1109 input variables, charge measurement, above limit. Possible fault causes as per wm, heavily soiled throttle, throttle body itself, or Mass Air flow sensor. I would suspect this fault is caused by the fault (p1250). Like many others have suggested, take a good look at both wastgates, control lines, air diagphram, linkage etc. if the faults return. Correct me if I am wrong, that the faults were present with the split inter-cooler hose and have not returned to this date?? The lack of boost .7bar is a direct result of the split hose, and the faults you provided could also be caused by this (split hose).
12-12-2008, 09:25 PM
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The wastegates are actuated (opened) using a pressure 'signal'. The purpose is to 'protect' the engine as boost increases.
If one or both of the rubber pressure lines TO the wastegate are cracked and leaking, then the wastegate will not open. If the wastegate is corroded or broken or the internal bladder is ruptured then the pressure will not open the wastegate...finally, if the flap door inside the wastegate is stuck, then the pressure to the wastegate itself may not be opening the door.
I vote cracked hose to the wastegate.
I am a bit disturbed with the discussions of octane and boost- if your car is stock, something is wrong. Fix that, don't try to change the octane to accommodate the fault.
IMHO
A
If one or both of the rubber pressure lines TO the wastegate are cracked and leaking, then the wastegate will not open. If the wastegate is corroded or broken or the internal bladder is ruptured then the pressure will not open the wastegate...finally, if the flap door inside the wastegate is stuck, then the pressure to the wastegate itself may not be opening the door.
I vote cracked hose to the wastegate.
I am a bit disturbed with the discussions of octane and boost- if your car is stock, something is wrong. Fix that, don't try to change the octane to accommodate the fault.
IMHO
A
12-12-2008, 10:03 PM
#37
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1. Inspect for obvious damage or corrosions/fouling
2. Check condition of pressure hoses to the wastegate/actuator
3. Test wastegates for actuation- attach a pressure soruce and make sure you can move them with 8-15 psi.
4. Pressurize the hoses that WERE attached to the wastegates- look for pressure leaks in the hoses. (Since I haven't looked at this I don't know what the pneumatic circuit looks like- will it be closed when the car is off? I know the pressure TO this is controlled by a valve, but I don't know the state of the valve when the car is off.)
If this all checks out, then you are up to 'does the N75 control valve work?' I suppose it could be not working- either it is broken and not switching the pressure or it is not getting the electrical signal. I'd suspect the electrical continuity is checked by the DME, and if it were bad you might get a code.
But, you've had one ripped hose, right?... look to the pressure hoses to the wastegates. It's that old medical diagnostics adage: "When you hear hoofbeats, don't think zebra"
My 2 cents.
A
PS I misunderstood on the flashing/octane issue. Personally if my car was flashed and I could NOT verify the 'provenance' (ie who wrote the flash, what it does) I would reflash it to stock and call a 'top tier' vendor for a new flash.
Last edited by adam_; 12-12-2008 at 11:48 PM.
12-13-2008, 03:43 AM
#38
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Give me a call and I can work you thru the boost issue and programming issue.
BTW Adam does have the correct approach in correcting your problem.
I listed early on that you might have a stuck actuator or control hose issue. These things need to be checked.
BTW Adam does have the correct approach in correcting your problem.
I listed early on that you might have a stuck actuator or control hose issue. These things need to be checked.
