Hi Long time member with no troubles till now! Very slow until 2000 rpm then seems ok Won't pull without going down a gear or two I will change air cleaner out But that doesn't seem to be a problem Doesn't show any codes Anyone got any ideas Regards xkkat
No power until 2000 rpm D40 2.5
- Thread starter xkkat
- Start date
Help Support Nissan Navara Forum:
It's possible that your turbo isn't doing what it's supposed to do. There are several possibilities:
1) Very common - vacuum lines loose or cracked and losing vacuum. If they look old, consider replacing them (about $20 tops).
2) Very common - Boost Control Solenoid. This little guy lives on the intercooler hard pipe up the front of the engine bay. Follow the vac line that comes across the top of the motor to its end - that's the BCS. Test: remove the vac line you just followed, and install it on the turbocharger directly. Power restored: BCS has failed, Nissan charge about $240 but you can get on eBay for about $40, or dump the BCS altogether and get a Tillix/Dawes valve (about $160 perhaps).
3) Not very common - dirty sensors. Usually just the MAFS at fault (and it's usually just dirty, hardly ever a sensor failure). Remove it from the back of the air pipe just out of the air filter box and use spray contact cleaner (never, ever put any hard object inside, even a cotton bud could destroy it) then reinstall.
4) Not common - turbo issues. Sometimes it's a bad actuator, although we haven't seen many reports of that recently. The Garrett 2056V has brass journal bearings and can suffer from varnish buildup if the engine is shut down while the turbo is hot. Remove the front hose from the turbocharger and try turning the impeller - it should rotate a tiny bit reluctantly but smoothly without wobble in the shaft. If that's not the case - the turbo is at the end of its life. Options: rebuild kit from eBay (sometimess < $100), Chinese replacement ($400-$600), genuine but not Nissan about$1300, Nissan genuine $2500-$3000 depending on how you get it (figures are approx and may not be accurate today, this was ~2 years ago)
5) Not common - exhaust problems. The turbocharger is driven by the exhaust. If the exhaust is leaking (broken EGR tube, for instance) you'll have less pressure on the turbine which means reduced spin = poorer performance. Look for black sooty emissions around the exhaust and EGR tube.
6) Not common - neutral/park switches faulty. The ECU decides to downrate the engine power if the car is in neutral or park so a faulty NPS in the gearbox may cause the ECU to not command as much boost (you'll still get some, but it will be noticeably less). A workshop that can query the gearbox will be able to see this, but you can test by unplugging the NPS which has to show a voltage to the ECU to indicate neutral (no voltage on NPS line means it's in gear).
There's a bit to start with.
Edit: added 6.
1) Very common - vacuum lines loose or cracked and losing vacuum. If they look old, consider replacing them (about $20 tops).
2) Very common - Boost Control Solenoid. This little guy lives on the intercooler hard pipe up the front of the engine bay. Follow the vac line that comes across the top of the motor to its end - that's the BCS. Test: remove the vac line you just followed, and install it on the turbocharger directly. Power restored: BCS has failed, Nissan charge about $240 but you can get on eBay for about $40, or dump the BCS altogether and get a Tillix/Dawes valve (about $160 perhaps).
3) Not very common - dirty sensors. Usually just the MAFS at fault (and it's usually just dirty, hardly ever a sensor failure). Remove it from the back of the air pipe just out of the air filter box and use spray contact cleaner (never, ever put any hard object inside, even a cotton bud could destroy it) then reinstall.
4) Not common - turbo issues. Sometimes it's a bad actuator, although we haven't seen many reports of that recently. The Garrett 2056V has brass journal bearings and can suffer from varnish buildup if the engine is shut down while the turbo is hot. Remove the front hose from the turbocharger and try turning the impeller - it should rotate a tiny bit reluctantly but smoothly without wobble in the shaft. If that's not the case - the turbo is at the end of its life. Options: rebuild kit from eBay (sometimess < $100), Chinese replacement ($400-$600), genuine but not Nissan about$1300, Nissan genuine $2500-$3000 depending on how you get it (figures are approx and may not be accurate today, this was ~2 years ago)
5) Not common - exhaust problems. The turbocharger is driven by the exhaust. If the exhaust is leaking (broken EGR tube, for instance) you'll have less pressure on the turbine which means reduced spin = poorer performance. Look for black sooty emissions around the exhaust and EGR tube.
6) Not common - neutral/park switches faulty. The ECU decides to downrate the engine power if the car is in neutral or park so a faulty NPS in the gearbox may cause the ECU to not command as much boost (you'll still get some, but it will be noticeably less). A workshop that can query the gearbox will be able to see this, but you can test by unplugging the NPS which has to show a voltage to the ECU to indicate neutral (no voltage on NPS line means it's in gear).
There's a bit to start with.
Edit: added 6.
Last edited:
