Strange throttle operation - 2.0TDi

[Lewwy]

I have an issue with my 2.0 TDI (BKD) Octavia when pulling away from a standstill. When I change into 2nd and then 3rd gears and gently accelerating, I get a momentary surge of acceleration (approx. 1 sec) - its as if I am pressing harder on the loud pedal - although I am not and am using the same amount of steady pedal pressure.

 

I haven't really noticed it in 1st gear at all and not really noticed it in any of the other gears apart from 2nd and 3rd.

 

This can be more pronounced at certain times but I haven't determined a pattern for when it does it.

 

 

This weekend I have had two instances where when accelerating up a slight incline in 3rd and holding steady revs approx. 2000 - 2200rpm the cars feels as though I am taking my foot on and off the throttle

repeatedly, kind of jerking. I have tried to recreate it on a couple of inclines and cannot not repeat it after it has done it.

 

The clutch pedal is reasonably weighty, but nothing out of the ordinary compared to previous VAG cars I have owned, clutch doesn't rattle, clatter or make any strange noises (yet!). Its pretty smooth on the uptake and doesn't jerk or judder when pulling away in 1st. The car is a 2007 L&K and has done 51,800 miles.

 

Any ideas appreciated.

 

 

Lewwy

[@Lee]

you sure it's not just the turbo kickin in? Rev range seems about right for the gears.

[Lewwy]

Hi,

 

When it surges momentarily in 2nd and 3rd gears its at approx. 1200 rpm so I wouldn't think it is turbo related.

 

The jerkiness I experienced when going up an incline may be related to the turbo?, but when it happens I am holding the throttle steady and the car is moving at a constant steady speed, then it suddenly feels as though I am lifting off and then re-applying the throttle quite quickly. Very strange sensation to be honest.

 

 

 

Lewwy

[@Lee]

dumb question maybe, but were you in the correct gear for the road?

Other option, fuel line problem.

[Lewwy]

As for the correct gear, the 2nd and 3rd gear surging happens when changing into the gears driving normally on a normal flat road.

 

As for the jerking its when going up incline and holding in 3rd, revs at approx. 2200 rpm which for a 140 TDI is fine, using a higher gear and lower revs in the same situation would put more strain on the clutch DMF.

 

I need to look at service history and see when the fuel filter was last changed (I've owned the car since Dec 2013).

 

This could be something to look at.

 

 

Lewwy

[hobbes42]

I had similair symptoms to this and the boost hose from the intercooler had come loose. Surprisingly the car still ran fine apart from juddering at low speed and low throttle inputs...

[Lewwy]

I had similair symptoms to this and the boost hose from the intercooler had come loose. Surprisingly the car still ran fine apart from juddering at low speed and low throttle inputs...

 

Oh ok, something I will have a look at then will have to get it up on the 4 poster and see if anything obvious. Was it the bottom hose that comes from the intercooler that you had loose? Did you have any other symptoms with that?

 

 

Lewwy