Crazy T6 ! Out of control !

[Peter Rhymes]

Hi, my 2017 T6 recently decided to go crazy . The revs went up to the red line no matter what I did . It was quite scary and I had to turn the ignition off when approaching traffic lights . The RAC advised that the acceleration sensor had gone open circuit . I had a local garage change the sensor even though they told me that it was now behaving . Has anyone else had this problem ?

 

[Loz]

The throttle sensor is a dual module, so shouldn’t do this.
Have you checked your oil level?

 

[Dellmassive]

That's just what I thought.... @Loz

First impression was was failed turbo and runaway redline off engine oil...?


The throttle body/flap and throttle Peddle both have dual redundant sensors to stop this from happening.... And a diesel engine needs fuel too run.?


I had this with a turbo failure yonks ago on an old vaux astra 1.9l diesel....the problem then was that the intake was open all the way through so switching off the ignition didn't stop it..... I had to try and stall the engine with the clutch and gearbox before the engine destroyed itself.

 

[Dellmassive]

Very strange...

Keep us posted on any further details.

 

[Spaghetti]

Hi, my 2017 T6 recently decided to go crazy . The revs went up to the red line no matter what I did . It was quite scary and I had to turn the ignition off when approaching traffic lights . The RAC advised that the acceleration sensor had gone open circuit . I had a local garage change the sensor even though they told me that it was now behaving . Has anyone else had this problem ?

I thought about dieselling too, but turning the ignition off wouldn’t help, unless the air intake was choked off when you turn the key off?

Lots of failed regens may have raised the oil level in the sump so far that the engine consumes the engine oil as fuel by passing it past a failed oil seal in the intake (normally turbo) .

Look up diesel runaway on YouTube

 

[Dellmassive]

The T6 Diesel engine has a Throttle body.

its used to shut-off the airflow into the engine to stop diesel over-run and chattering on shutdown. ( most modern diesels have them now)

it can also prevent over-run.

they are not used as a throttle like in petrol engines . . . in a diesel its the injectors and turbo that create power.

....



example here:








.






+++


J338

 

[DXX]

Not sure what engine you have (code) but if your van is fitted with an intercooler pull the bottom hose off and see how much oil sludge drains off.

 

[Dellmassive]

FWIW . . . .

as above the " Accelerator Pedal module" - GX2

has two independent sensors . . - G79 / G185


these are normally opposite readings. . .

so 0-100% and 100-0%

the ECM compares the two readings as a fail safe. . .

 

[Peter Rhymes]

The throttle sensor is a dual module, so shouldn’t do this.
Have you checked your oil level?

The engine oil is fine . The RAC diagnostics indicated an open circuit throttle sensor so I am hoping that now it has been replaced it will be ok . The Van was driven over 100 miles back to me so fingers crossed !

 

[Spaghetti]

The T6 Diesel engine has a Throttle body.

its used to shut-off the airflow into the engine to stop diesel over-run and chattering on shutdown. ( most modern diesels have them now)

it can also prevent over-run.

they are not used as a throttle like in petrol engines . . . in a diesel its the injectors and turbo that create power.

....



example here:


View attachment 173105


View attachment 173106


.



View attachment 173107


+++


J338


View attachment 173108

Similar to the ‘anti shudder’ valve on the wife’s A4, although that’s a vacuum operated butterfly to aid smooth shutdown. Good in case of runaway too though!