Thread: 3.0l Turbo malfunction

Originally Posted by v8sruleok

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.

on the sequential turbo 3.0l, the vacuum solenoid operates even at idle speed. If you let the car idle for a few minutes you’ll hear the exhaust note change as the vacuum solenoid opens the air valve and the second turbo is spooled up, this is to ensure the second turbo gets enough oil and is cooled.

My experience was similar, at 120,000km (about 3 years ago)I got the restricted performance triangle, original diagnosis was the solenoid, this was replaced under warranty. Still the same fault, next the diagnosis was the primary turbo, also replaced under warranty, then finally the air control valve also under warranty. No further issues to date.

Originally Posted by LRD414

The WSM statement mentions cycling the turbine shut-off valve during idling but not the compressor shut-off valve, which is the one that typically sticks.

Scott

Rereading it, good point.