STX550 V9X

[D40STX]

Hi All, Has anybody had problems with their STX550 VX9 Rattling, Blowing Black Smoke and Loosing Power when towing.
Mine has developed this after I travel between 10 and 20 km towing a caravan .without the caravan it is perfect

 

[Old.Tony]

It sounds like the turbocharger is not performing as well as it should. Do you have a bluetooth ELM327 OBD adapter and a phone app like Torque? You could ask it to provide boost pressure and it will let you monitor that (and a bunch of other stuff) in real time. I don't recall what typical boost pressures for the V9X are (I'll edit the title of the thread in a sec to fix that).

It might not be a failing turbocharger (although that's possible). The turbocharger controls may be damaged (or just old!). In the YD25 that's the vacuum control (Boost Control Solenoid) or the vacuum itself (usually just a hardened or cracked vac hose). I don't recall the actuator's mechanism in the V9X, sorry.

There are other possibilities, but black smoke coupled with a loss of power is usually a turbocharger that's not doing what it's supposed to. Check the boost levels and get back to us, if it's still providing good boost then it could be something about the air path (MAFS, unlikely because it's only when it's under load) - or perhaps it's overloading the intake with EGR.

 

[landmannnn]

The V9x has a vacuum operated boost controller, they have been known to fail.

 

[YCJCYASATB]

Hi All, Has anybody had problems with their STX550 VX9 Rattling, Blowing Black Smoke and Loosing Power when towing.
Mine has developed this after I travel between 10 and 20 km towing a caravan .without the caravan it is perfect

I’m only new and have a similar issue. Although I have a Ti550. I’m not getting the rattling or black smoke. But after approx 70km towing my 2t van my fuel consumption goes from sitting at about 17L to about 25L. Obviously requiring more fuel to compensate for a loss of power. Seems to be fine in 4th with plenty of power and better fuel consumption at 3000rpm than in 5th at about 2200rpm in that fat torque band.

I didn’t have any means of monitoring parameters but am also leaning towards charge air system. I’m glad I am not the only one with this problem. To say I was surprised to be using more fuel than my old 105 series Landcruiser 6cyl petrol, towing less weight and at 10 km/h slower is an understatement.
I will look into boost controller and possible boost leaks as I still have the original charge air cooler. Hopefully it’s not a turbo, goes like a scalded cat when in the first 4 gears when towing and unladen all gears are good.

Regards.

 

[D40STX]

It sounds like the turbocharger is not performing as well as it should. Do you have a bluetooth ELM327 OBD adapter and a phone app like Torque? You could ask it to provide boost pressure and it will let you monitor that (and a bunch of other stuff) in real time. I don't recall what typical boost pressures for the V9X are (I'll edit the title of the thread in a sec to fix that).

It might not be a failing turbocharger (although that's possible). The turbocharger controls may be damaged (or just old!). In the YD25 that's the vacuum control (Boost Control Solenoid) or the vacuum itself (usually just a hardened or cracked vac hose). I don't recall the actuator's mechanism in the V9X, sorry.

There are other possibilities, but black smoke coupled with a loss of power is usually a turbocharger that's not doing what it's supposed to. Check the boost levels and get back to us, if it's still providing good boost then it could be something about the air path (MAFS, unlikely because it's only when it's under load) - or perhaps it's overloading the intake with EGR.

 

[D40STX]

It sounds like the turbocharger is not performing as well as it should. Do you have a bluetooth ELM327 OBD adapter and a phone app like Torque? You could ask it to provide boost pressure and it will let you monitor that (and a bunch of other stuff) in real time. I don't recall what typical boost pressures for the V9X are (I'll edit the title of the thread in a sec to fix that).

It might not be a failing turbocharger (although that's possible). The turbocharger controls may be damaged (or just old!). In the YD25 that's the vacuum control (Boost Control Solenoid) or the vacuum itself (usually just a hardened or cracked vac hose). I don't recall the actuator's mechanism in the V9X, sorry.

There are other possibilities, but black smoke coupled with a loss of power is usually a turbocharger that's not doing what it's supposed to. Check the boost levels and get back to us, if it's still providing good boost then it could be something about the air path (MAFS, unlikely because it's only when it's under load) - or perhaps it's overloading the intake with EGR.

 

[D40STX]

Hi Old Tony and others,

Finally got it sorted out.
I took it to my mechanic he cleared any fault codes, ran it up on a dyno and got it to re create the fault, with no faults showing on the scanner . tried all sorts of things changed suction control valve on fuel pump, blanked of EGR valve, cleaned Air Flow Meter, Changed both Primary and Secondary filters running it up after each change all to no avail contacted several Fuel Injection Services and Mechanical Services not one of them had ever come across this problem . while on the Dyno again wiggled some wiring to find the Electrical Patch Harness to the fuel rail and glow plugs were not connecting properly .

thank you to everybody who offered advice.

 

[Old.Tony]

Electrical gremlins strike again! Glad to hear it's been resolved.

 

[Cowboy550]

Dose a A9X engine have glow plugs ?

 

[landmannnn]

Yes