D40 loses power when hot

[Brad20v]

Hello
I'm hoping someone might have come across this problem.
Vehicle is a 2013. Thai build.128kw Auto pov pack.
Long story so please hang in there.
Originally engine light came on and went into limp mode after driving up windy mountain , Kangaroo Valley.
Nissan said the error code was not applicable to the vehicle and reprogrammed the ecu.
I think it was better, ...
For the Last 2 years, the vehicle loses power under load up hills , more when the weather temp is hot.
When it loses power the OBD2 reader I have shows the boost drops from its usual 20psi down to around 10psi.
A few Shops have looked at it, thus far it's had a new suction control valve, 4 new injectors, and airflow Meter, replacement of the cracked exhaust manifold,and still the same. The work shops don't seem to listen to the loss of boost when hot.
I'm thinking it may be some sort of sensor playing up...But I'm not sure.The engine light does not come on, though it did yesterday.
When it plays up, it's like it gets stuck in the gear. Example, doing 100klm hit hill, slowly drops to 80klm with foot flat. I can then pull shooter back to second even first and it does not change revs.
$10k has been spent, still no good. Luckily it's a company vehicle.
It's like chalk and cheese compared to my R51 patchy.
Please please help
Thanks

 

[Old.Tony]

Welcome to the forum.

First suspect: BCS, if it's vacuum controlled (if not, ignore this). You can bypass it to test the theory but be aware that the turbocharger can produce enough boost to blow the hoses off. Here's how: find the vacuum hose that crosses over the top of the engine from the right hand side and makes its way to a small black gadget hanging off a 75mm black pipe. That pipe is the feeder to the intercooler. The gadget is the BCS. Remove the discovered hose from the BCS and replace the hose on the actuator with it - you are now connecting the turbocharger directly to the vacuum pump, so the turbo will be on full at all times. Probably best to do this once it's hot and playing up (with gloves, you can do it without shutting down the engine).

If you have an electronic actuator, go back to Nissan and see if it's been replaced. The early electronic actuators were faulty and Nissan recalled them to fix them up.

Only other possibility is the turbo itself. When hot, it is possible for the thing to bind up. The Garrett 2056V has brass journal bushes and if they get a little varnish on them they could bind when heated.

 

[Farmer Joe]

I had a similar problem with my 2011 D40 it turned out to be a faulty EGT sensor. Nissans replaced it foc

 

[Brad20v]

Thanks guys
I will look into the BCS, I always had thought it May be the culprit.
As for Nissan,... There usual response is no fault found, customer to monitor.
Probably because they can't do much more than change oil and strip my sump bolt thread.

 

[Gavand]

Hi Brad I know this is an older thread but having a similar problem on a hot day, how did you go?