12 replies to this topic

[B4AUS]

Hi all,
I am looking for advice on a infrequent issue I am currently having with my B4 ADM engine. This problem being an apparent boost leak (or I think) which comes on during the later rev range when the 2nd turbo is activated. This leak is physically felt as the car looses considerable power and surges back and forth loosing and regaining boost all whilst being accompanied by a check engine light. However this leak (or what I think it is) is indiscriminate, in that at some points the second turbo spools and no boost loss is noticed, where as other times the boost loss is monumental. Being the noob I am, I am wondering if this issue could be something else entirely and if so what would you reccomendations be on the issue or its remedies. I obviously understand having the code checked would be a start, I however would like some knowledge before sending it to subaru to be checked.

Thankyou x9000

[allpaw4]

I had something similar where the car would put itself into limp mode, but wouldn't log a code. Once I got it to log the code (make it do it several times in one drive) it was simply a case of read what the scantool said and replace the faulty component. In my case it was the cam position sensor. But my symptoms were slightly different. Basically you need to keep driving it until it faults a couple of times on the one startup. It won't log the code unless you do this.

Have you had the codes checked?

[cowie165]

When the secondary should be boosting, can you hear unusual noise? You may have a loose IC pipe. They're plastic pipe fitting onto metal IC so the seal isn't great and they are prone to slipping off if the clamps aren't secure.

 

Actually, if you're getting an intermittent compressor stall I wonder if it's more likely a failing sensor than a vac issue. Definitely start with codes like allpaw suggested.

[Grahama]

Sounds like another car of mine (Toyota) when it hit boost cut - turned out the boost line to the actuator solenoid had fallen off, so the wastegate would never open
I did get a MAP sensor error, which I replaced, but it took me a while to work out it was over boosting.

(just giving you something else to check)

[Robbks]

Step 1) CHECK THE CODES

Step 2) Reset ECU

 

[LukeFranky]

I had a exactly the same problem and it was caused by the limp mode.

 

In my case the limp mode was triggered by a seized primary turbo. It was producing very little boost so it would bring on an engine light up long hills. Once the light was on and I engaged the secondary turbo there would be a sudden rush of power which then led to being thrown forward in my seat by a boost cut. Turning the key off and on cleared the limp mode.

 

P1241 was the error code if I recall.

[B4AUS]

Thanks for the input I will taking it to a mechanic soon to address the issue. Strangely today whilst driving the car on full boost I had no issues like these even though they where occurring almost every time prior on full boost. Could this be due to today's colder conditions playing am impact or simply a random coincidence.

[PeeKay]

If there was a boost leak you'd hear it, and it would happen consistently in hot or cold conditions. Could be a solenoid playing up?

[Robbks]

Step 1) CHECK THE CODES


 

 

 

[B4AUS]

It was cam sensor. Only found in the temp files of the ecu as it would activate then dissappear after you no longer accelerate.

[allpaw4]

Good to hear you sorted it. Out of curiosity, how many km on her? Mine failed at about 160k.

[B4AUS]

188,000 and driving like a dream now. I had the belts changed around 5000 kms ago, along with other bits and pieces. In addition I had the rear main done preemptively. Expecting many more kms out of the car.