3.0d Turbo Pressure Convertor Valve
 

Hi All,

So I don't appear to have any boost on my 3.0d

Using a vacuum pump directly on actuator on the turbo itself it's holds about 23 Hg and I can see the rod clearly move. Removing the vacuum suddenly results in a mechanical clunk - so I think the wastegate/VVT is moving ok.

The pressure convertor is I think the problem but I'm not sure how to properly test it. If I apply a vacuum to the in pipe, whilst blocking the out pipe - it will get to about 23 Hg but it will not hold it - and in approx. 15 seconds, it is back to zero. I have tried new pipes, so think it is the unit. I believe it is supposed to hold the vacuum and only release when pulsed with 12v ?

Any help appreciated.

Thanks as always.

Certainly sounds like the pressure converter could be leaking but they are modulated by a square wave signal in normal operation so testing requires more that just a leak-down test.

https://www.youtube.com/watch?v=lKnE0RDVXBU

There may be other causes for vacuum issues too. You can check the vacuum reservoir (#1) and the lines you can get at, but the vacuum manifold that feeds this is under the intake manifold.

https://www.newtis.info/tisv2/obj/8SZYevV

https://www.newtis.info/tisv2/a/en/e...ontrol/AXdsYr2

https://www.newtis.info/tisv2/obj/8ETk3r4

https://www.newtis.info/tisv2/a/en/e...-valve/AVr13z5

At least the VVT vanes (there's no wastegate in these turbos) seem to be working. :thumbup:

Fantastic response as always Wayne - many thanks. :thumbup:

I didn't realise the valve/controller is the same as used for the EGR (which is now blocked off). So will test that one as well and just block it off at the main vacuum tube if it's leaking - as while I don't need it to be working, I guess I may be loosing vacuum here if it is.

I've ordered a new Pierburg one - as both are originals, so it's done ok for 17 years of service !

Thanks for diagrams - very useful.

So I have replaced the pressure convertor valve. I tested it before installing and can confirm that pressure is held in the unit - it does leak very slowly but that is likely my cheap vacuum pump.

I also checked the vacuum from the main pump when the engine is off and that held solid - so I'm confident I have no other vacuum leaks on the old EGR pressure convertor valve. If I did, I would have simply bypassed it as I now have no EGR anyway ..

The car now pulls strongly from much lower revs so I think this is now fixed.

Thanks for the update! :thumbup: