ZD30 ... Low boost

Hi members

Need some advice !

Nissan 2005 GUIV zd30

l have dawes set up , needle valve, egr . etc. My patrol has been running fine last few years. Last week i realised my Boost was lower than usual . I though it was probably need adjustment. I stretched the spring and it was set fine back to normal. A few days later , Im struggling to get over 10Psi , with crap fuel economy. I tried to stretch the spring again. Didn't work , I also ordered some more heavy duty springs, still couldnt get past 10psi.. I tried another Dawes valve, still struggling to reach 10psi. I played around with the needle valve, the actuator level moved .

I'm thinking maybe the wet weather had something to do with it. I couldnt find any obvious boost leaks .

Any ideas guys ?

TIA

Limmy

Egr stuck open? Unless it’s blocked that is.
Otherwise check all turbo and intercooler pipework for loose hose clamps, boost gauge lines, intercooler etc for leaks

EGR blocked. Can I do the soapy water trick to test the lines and pipes. Will it still have boost pressure while it idling so I can test ?

What intercooler do you have, if its the OE one chances are its leaking.
easy to check if its oily its leaking

I got a welded intercooler. I did notice a bit of oil around my boost sensor on the intercooler. I got one of those boost gauge adapter's that sandwich between intercooler and boost sensor. Maybe that leaking . I might silicone it

Sounds like it could be a vacuum problem to me. Soapy water won't show a vacuum leak. Usually the hoses split in the most difficult to see spot. You will have to check the hoses one at a time.

Quote:

---

Originally Posted by threedogs

What intercooler do you have, if its the OE one chances are its leaking.
easy to check if its oily its leaking

---

^^^^^This...

Quote:

---

Originally Posted by Limmy

I got a welded intercooler. I did notice a bit of oil around my boost sensor on the intercooler. I got one of those boost gauge adapter's that sandwich between intercooler and boost sensor. Maybe that leaking . I might silicone it

---

....and this.
Boost leak 100%.

And no need to stretch the spring in the dawes anymore. This issue was corrected with a stronger spring about 3 years ago. Unless you have one of the older Dawes with the old spring then disregard my comment.

i had the older one. ive put on another one ( smaller one with ceramic ball ).. Where would the vacumm hoses be located ? Im going to buy new silicone hoses tomorrow. clean my intercooler.

Start at the hose connected to the turbo actuator and work back to the vacuum pump located on the front of the engine. Also - there are vacuum hoses connected to solenoids under the intercooler. That was where mine were split.

I think i may have found the problem. While i was replacing all the lines with new silcone ones. i was removing old line from the " boost gauge inline filter " i notice it had a crack and split apart a bit when i pull it. It has some black soot in between the joins. I blew air and it definately is leaking.

Hope that is the main problem ! im ordering another filter

keep you posted !

Attachment 73941