I installed the vent to atmosphere dump valve about a year ago and until now I've had no problem. At revs above 3000RPM you hear the 'Phssst' sound, but never below these revs.

In the last couple of days, the dump valve has been creating a less audible 'Phssst' sound at extremely low revs, and at low speeds can nearly cause the engine to stall.

I'm obviously worried that this could damage my engine or turbo, if left unchecked. Before I take it down to a garage, I was just wondering if anyone else has experienced this, or could shed some light on what it might be.

Cheers.

 

It sounds as though the piston is not working correctly. It may becoming seized. It could have dirt in there.. Try just squirting it with WD40.. Or if that has some or no effect. Take it off and give it a good overhall. Hopefully the spring is ok and hasn't broken and wedged..

 

Is there any immediate danger here, do you think?

 

Not really unless it seizes completely, then no excess pressure is being dispersed and you you will get the pressure pushing back on the blades of the turbo and slowing them down. This would in the long term decrease the life of your turbo. But short term should not have any adverse affects.