Vacuum Leak

[matgriff]

Having a few little annoying faults with my 2007 GV at the moment....grrrrr

One problem I've noticed, after switching the engine off, I can hear a hising noise for about 15-20 seconds, then it stops.

I've reasoned that it's some kind of vacuum leak, because pressing on the brake pedal (ie operating the servo) when the engine's switched off causes the hissing to stop sooner. It's coming from the area to the right of the dipstick tube, there's a load of tubing/valves in that area, nothing obvious is damaged.

It's definitely a vacuum leak, because I've also noticed that after the hissing has stopped, the brake pedal is solid, just like the servo is exhausted.

It's probably leaking when the engine is running but I can't hear it due to the background noise.

Any ideas ???

cheers

 

After further reading on the forum, I think this could well be related to the EGR valve ??? 

Edited January 4, 2016 by matgriff

[Dazandtrace]

Hi can you give more info on why it could be egr. As iv had the same sort of thing on my voyager 2.8 crd

[matgriff]

Update : I worked out that the leak seemed to be coming from the little 3 port vacuum valve that controls the EGR.

 

I took it off cleaned it with brake cleaner and the WD40, reconnected it and all seems well.

 

If I disconnect the white connector at the top port, I get engine vacuum. When I reconnect it all, on starting the engine the EGR valve is at it's spring loaded rest place, then when the air con clutch engages about 20-30secs after starting, the EGR valve moves about half way.

 

On switch off, there's no more hissing.

 

The bottom port on the switch has a little black cap with foam in. It doesn't look airtight, but I'm not sure if it's supposed to be ???

 

Mat

[Dazandtrace]

Ok good report ill take a look at mine at the weekend