Thread: 3.0l Turbo malfunction

Peter,

So is she all good now ?

Amazing that with modern diagnostics that a faulty part can't be pinpointed first time around.

Brett...

It sounds like the diagnostics pin pointed the actual failure but not that it was caused by the control switch. Interesting that it occurred straight after a service. It has happened to me in many different vehicles, especially my BMW motorcycle, that bad things always happen straight after a service that did not go anywhere near the offending part. Its either Murphie's Law or the mechanics are doing stuff that we don't know about.

Bob

Originally Posted by discotwinturbo

So is she all good now ?

Yeah, all's good and good to know it was not the turbo itself given the stories others here have told.

Rob (you know who) reckoned the diagnostics just weren't leading them there. I think there is a bulletin issued for the compressor isolation valve jamming so I think they were focused on following through on the testing and diagnostics that was telling them to perform rather than looking further a field. The valve was non operational but not because it was jammed, just behaving like it was.

Originally Posted by BobD

... bad things always happen straight after a service that did not go anywhere near the offending part. Its either Murphie's Law or the mechanics are doing stuff that we don't know about.

Tell me about it. Last 2 out 3 routine services the dealer has provided me has ended in limp mode and a tilt tray ride within ~25 km of leaving them. To their credit this time, they had me in a loan car by the 3rd day, but still ...

There is a quick test procedure used to determine if the valve is sticking. It involves temporarily removing then refitting the vacuum hose to that solenoid but with certain time delays. It seems that the dealer didn't do the test which would have revealed that the solenoid was faulty and would have prevented all the other work and unnecessary delay.

Edit: It seems that the test was done but the lack of vacuum at the solenoid wasn't detected nor was the valve checked for sticking once removed.

Originally Posted by Graeme

... nor was the valve checked for sticking once removed.

Yeah, that occurred to me also once the real fault was identified.

I suppose that if the valve can stick for reasons other than the external dirt that caused mine to stick then there could be a case to replace it anyway. Hopefully the replacement has the external fittings redesigned to prevent jamming from dirt so that at least you have some benefit from being without the vehicle for so long. Mine however will again stick unless something gets changed.

Originally Posted by Ferret

Yeah, all's good and good to know it was not the turbo itself given the stories others here have told.

Rob (you know who) reckoned the diagnostics just weren't leading them there. I think there is a bulletin issued for the compressor isolation valve jamming so I think they were focused on following through on the testing and diagnostics that was telling them to perform rather than looking further a field. The valve was non operational but not because it was jammed, just behaving like it was.




Tell me about it. Last 2 out 3 routine services the dealer has provided me has ended in limp mode and a tilt tray ride within ~25 km of leaving them. To their credit this time, they had me in a loan car by the 3rd day, but still ...

Hi Ferret,

I realise that it's been nearly 6 years since this thread was last active.

I have just been googling D4 shut off valve because I'm thinking this could be one of the issues affecting my car.

I was interested to see that your pictures and my own diagnostics seem to arrive at the same point, but the problem is that I'm just not sure of the circumstances that would open the TSOV. I climbed underneath the vehicle and had a good view of the actuator arm then asked the missus to rev the engine to 3K. The test was repeated a few times at varying revs and the actuator arm did not move at all.....though I can operate it manually so it's not seized. I took the vacuum line off and there was no suction at all. I traced the line back to the area in your pic and pulled the hose off at the solenoid and still could not get a vacuum response.

Do u know what sort of rev range/or other circumstance will open the TSOV as I may not be achieving the criteria for the solenoid to activate vacuum to this line?

Thanks, Mike.

Originally Posted by v8sruleok

Do u know what sort of rev range/or other circumstance will open the TSOV as I may not be achieving the criteria for the solenoid to activate vacuum to this line?

Sorry, can't really help you with that one, don't know enough about such things.

Just as bit of an experiment I did connect my GAP tool and set it up to measure and view the air flow from both MAFs thinking this should say something about whether the TSOV is open or closed.

Just sitting in the drive way and slowing revving the engine up to 3k you can see the air flow in one MAF increase with revs but the other MAF stays flat. But remember this is under no load conditions in the drive way.

On the other hand, stabbing the accelerator from almost any base rpm, you get both MAFs to respond in some way. Typically air flow from one goes up while air flow from the other goes down relative to each MAFs base level air flow at the base rpm.