Turbo Surge Under Boost

[Getaboutabit]

This is a carry on from another thread I may have hijacked a bit.
My car surges a bit whilst under acceleration Boost fluctuates
between about 11 psi to 16 or so. The car is a 2012 ST Cab chassis
3"exhaust Anything else is unknown at the moment. There is no external
sign of oil near or around the inter cooler although there is some visible
when you remove the intake hose. Inter cooler is standard
Still need to check the boost lines / hoses
Any thoughts

[threedogs]

Id be checking all boost and vacuum lines
What does it do if just cruising at say 60kph

[Getaboutabit]

sitting around 60ks car seems fine Only really happens
when running thru the gears I had a quick look at the
Vacuum and boost all seem tight and sealed I'll have a
better look during the week

[threedogs]

Maybe your IC is leaking as well, spray any sensors
making sure they are dry before re fitting them

[Getaboutabit]

Thanks for the reply Will check inter cooler, Would MAF sensor
cleaner be ok for any sensor If you run it upto or past 3000 rpm
there doesn't seem to be any fluctuation So may just need to drive
it a bit harder

[Tolch]

Got the same problem with mine - 2013 ST manual wagon. Looked, checked and cleaned everything I could find. A real pain in the b-m. Read heaps on the subject but no one seems to have a definitive answer. I am sure there are several possible causes so it is next to impossible to pin it down to just one or two things. I'll keep looking and checking as an when I can but running out of enthusiasm. If someone knows of someone else who has found a magic bullet I would be more than interested to know what they discovered.

[SG1]

Would dawes and needle valve solve this problem, taking boost control away from ecu and doing it manually?

[Getaboutabit]

I was thinking this may be worth a try
I don't think a Dawes valve ect costs much
so might buy them and see.

[threedogs]

I was thinking this may be worth a try
I don't think a Dawes valve ect costs much
so might buy them and see.

You'll need to fit some gauges to monitor your boost and egts once the egr block is in place

[Getaboutabit]

I've got Boost and EGT Gauges fitted
Do I need to block egr?

[threedogs]

In a perfect set up yes then the exhaust drives the turbo not the ecu so much,
In your case you may need to drill a 10mm hole in the EGR plate so the ECU
doesn't throw up the engine light all the time, unless you have a scan gauge or similar

[Getaboutabit]

Yes I've got a scan Gauge so will be able to clear
engine light if or when it comes on

[threedogs]

would it be worthwhile taking the IC off and pressure testing it.?

[Getaboutabit]

That should be easy enough to do
I wonder what sort of pressure it would take
Probably not much needed to test

[threedogs]

I would only use a bike pump, or a quick squirt with the air gun ,tape up one end
and dip it in some water,
Dry with a hair dryer before installing again.

[Mjcpatrol]

When was the last time you changed the fuel filter

[Mjcpatrol]

Had my surge under load and check light come on

[Mjcpatrol]

I check codes and it said dirty fuel or blocked fuel filter Chaged fuel filter and problem solved

[Getaboutabit]

It's going in for a service (40,000ks) this week so I'm waiting till that's done
before I do much else.

[Getaboutabit]

Just an update Nissan seem to think its a turbo problem
I'm getting a new turbo fitted next week all going well.
It's still under warranty so price is right will see what happens