hey fellas. need help. seems as though my d40 hits boost and then looses pressure. it seems to come on later than normal too and often boosts up again later in the rev range. kinda shits me cause theres no boost when u really need it. have checked vac lines and hoses and have recently replaced solenoid which fixed other turbo issues. the water pup also shit itself but that has now been replaced. was thinking it might have something to do with the egr but not sure. any advice would be much appreciated. thanks in advance
d40 boost problems
- Thread starter steveog
- Start date
Help Support Nissan Navara Forum:
With a blocked EGR you could lose boost through the intake-manifold side of the plate unless it's sealed properly, but this sort of phenomenon is usually the result of either leaking charge air hoses (that's what any hose between the turbocharger and the intake manifold is called) or a leaking exhaust manifold at the turbocharger interface.
That turbocharger interface can come loose (mine did). You'll see black soot around the exit of the leak and may even hear it as an odd whining that doesn't seem to go in time with the turbo but does seem to change with varying amounts of throttle.
A charge air hose leak will also be revealed by black emissions, but they'll be oily (or baked on from the heat).
Delays in boost could be swelling hoses - they do enlarge a little but shouldn't ever balloon because they're interwoven hoses. With a GoPro you could get some footage as you drive to see if the hoses are ballooning, you generally don't get a lot of boost sitting in neutral.
That turbocharger interface can come loose (mine did). You'll see black soot around the exit of the leak and may even hear it as an odd whining that doesn't seem to go in time with the turbo but does seem to change with varying amounts of throttle.
A charge air hose leak will also be revealed by black emissions, but they'll be oily (or baked on from the heat).
Delays in boost could be swelling hoses - they do enlarge a little but shouldn't ever balloon because they're interwoven hoses. With a GoPro you could get some footage as you drive to see if the hoses are ballooning, you generally don't get a lot of boost sitting in neutral.
hey tony thanks for the advice. replaced vac hoses, small thin ones from turbo to solinoid solinoid to air box and solinoid to side of engine. still no luck. misses is now saying there is white smoke coming through the air vents when ac is not on. also have noticed that actuator moves up when engine is turned on but doesnt move from there when revs are applied, is this normal?
White smoke through the air vents is a little odd, if there's any kind of weird smell in the cabin I'd get that seen to in case you're losing refrigerant!
I wasn't worried about the vac hoses, I'm talking about the big buggers that go between the turbocharger & intercooler and the intercooler & intake manifold.
Actuator movement is goverened by the vacuum and the solenoid, driven by the ECU which won't do gobs of boost while you're in neutral.
What I'd do: get a bluetooth OBD adapter, Android smart phone, Ian Hawkin's Torque app (from the Play Store) and find a decent hill. Start at the bottom, you only need one gauge - boost pressure. Hammer the thing - you should see the boost rise to around 20psi, it might make it as far as 24psi. You should expect it to do 18s-19s. Light acceleration will only see it boost to 10-12psi.
The turbo in the D40 doesn't really come on strong until the engine is doing around 1800rpm. Below that it's unable to get enough drive from the exhaust gas flow, but even then the drive is goverened by the vanes, which are adjusted by the actuator, powered by the vacuum pump directed by the solenoid and commanded by the ECU to NOT produce too much boost when it's not needed.
I wasn't worried about the vac hoses, I'm talking about the big buggers that go between the turbocharger & intercooler and the intercooler & intake manifold.
Actuator movement is goverened by the vacuum and the solenoid, driven by the ECU which won't do gobs of boost while you're in neutral.
What I'd do: get a bluetooth OBD adapter, Android smart phone, Ian Hawkin's Torque app (from the Play Store) and find a decent hill. Start at the bottom, you only need one gauge - boost pressure. Hammer the thing - you should see the boost rise to around 20psi, it might make it as far as 24psi. You should expect it to do 18s-19s. Light acceleration will only see it boost to 10-12psi.
The turbo in the D40 doesn't really come on strong until the engine is doing around 1800rpm. Below that it's unable to get enough drive from the exhaust gas flow, but even then the drive is goverened by the vanes, which are adjusted by the actuator, powered by the vacuum pump directed by the solenoid and commanded by the ECU to NOT produce too much boost when it's not needed.
Hey guys
Sorry to bring up an old thread but this seems like what is happening to my d40.
Using the odb2 sensor i can see the boost is hitting 20psi and drops to 3to5psi.
I also have noticed the actuator is not moving on idle. Although it drops when the hose is removed or engine is turned off.
Also the fuel rail pressure drops at the same time the boost drops.
I have
Replaced boost controller
Actuator
Fuel filter
Euc reset
Maf sensor cleaned
Did you get the issue sorted?
Sorry to bring up an old thread but this seems like what is happening to my d40.
Using the odb2 sensor i can see the boost is hitting 20psi and drops to 3to5psi.
I also have noticed the actuator is not moving on idle. Although it drops when the hose is removed or engine is turned off.
Also the fuel rail pressure drops at the same time the boost drops.
I have
Replaced boost controller
Actuator
Fuel filter
Euc reset
Maf sensor cleaned
Did you get the issue sorted?
The other parts to the control of the turbo are vacuum hoses and brake booster. The brake booster uses vacuum to operate. You can test the vacuum booster (it should just hold vacuum, if it's not, it's leaking) but you should make sure the vac hoses are all ok first (3mm ID hose, cost me about $5 per metre from Supercheap, you need 3m of it).
The only other thing I can think is happening is the SCV is giving you curry and causing the ECU to drop fuel supply (which might also drop turbo control, since the ECU is doing that too). While you're at Supercheap, grab a can of Liqui Moly Fuel System Treatment and throw it in the tank before you leave the car park. The worst it can do is clean the fuel system!
The only other thing I can think is happening is the SCV is giving you curry and causing the ECU to drop fuel supply (which might also drop turbo control, since the ECU is doing that too). While you're at Supercheap, grab a can of Liqui Moly Fuel System Treatment and throw it in the tank before you leave the car park. The worst it can do is clean the fuel system!
irie
Member
I am having the same problem as CJs. Could you explain how a leaking break booster could cause the boost to drop? On cold start I am getting a hiss from what i think is the booster. It goes away after pressing the brakes and using the truck for a bit.
