Engine misbehaving... 122PS

[clflangan]

Wonder if anyone can help me out with diagnostics?
I have a 2.0 TDI 140bhp manual which I bought new in July 2008. Regularly serviced, has driven 85,000km (on dodgy Irish roads) so far without any problems at all.

Over last 2 weeks, have had 3 episodes all of a sudden when engine seems to 'hold back' and go again and hold back again etc..Happens all of a sudden in middle of a journey, in any gear. Doesn't cut out or make funny noises, no warning lights on dash. Then problem mysteriously resolves itself again.

Feels a bit like 'kangaroo petrol'. Thought might be water in the diesel the first time but have filled tank lots of times since then from different garages, so unlikely to be problem with diesel itself.

Haven't got it to garage as yet, but any helpful hints?

Thanks!

[RW1]

There is a "holding back" or hiccup effect known problem with the TDi140. Linked to downhill after cresting a sharp peak of a hill or hump back bridge or undulating roads where the gradient suddenly changes?

If so, to do with the engine ECU reducing torque as it senses wheel speed and inclination of the Scirocco. Normal

TPI 2023854/1 29.06.10..

C.

[sciroccorocket]

I have a 2.0 TDI 140bhp manual which I bought new in July 2008
Could you get a Roc Diesel in 2008?

[maisbitt]

Thought the Roc 2.0TDI 140CR was made available about Nov 2008, with the 170 being available for order in July 2009.

[clflangan]

Thanks for your advice about the engine. It's a different problem to that strange sensation after cresting a hill which I noticed after buying it first and driving up and down the many hills near where I live!

The current problem seems to be something like the engine 'missing' from time to time, if that makes sense. I'm totally ignorant when it comes to mechanics, but it feels like the engine lacks power/fuel for a few seconds then gets it back again, then goes again etc...

I'm as bad at explanations as I am at mechanics!!

Thanks!

[RW1]

OK, then the suspect is the fuel filter. Could have been the diesel in the tank at the time of the first occurrance but now the filter is contaminated.

C.

[clflangan]

Thanks very much...will get it to garage ASAP...! Just to correct my original post, bought it in July 2009, my typing is brutal...!

[nazpatel]

exactly the same thing is happening with my 170 manual.
could you please keep me updated if it turns out to be a problem with car.

[clflangan]

Hoping to get it to garage over next few days so will update you if it's anything too serious!...

[clflangan]

Update on misbehaving engine... 2.0TDI 140bhp bought new in July 2009

Has been 'mis-firing' on and off over last 6 months but no associated warning lights until yesterday, when the Engine Management System light started flashing slowly on the dash, along with mis-firing. Got it to diagnostics in VW garage today to be told that the Throttle Valve was leaking, and needed replacing to the tune of €560 including parts and labour...!

A lovely Christmas present indeed...!

Has anyone come across a similar problem, and if so, am I being ripped off with that quote? Am due to return to garage in 2 days time for replacement valve, have been told that it is 'safe' to drive in meantime...

Would value some urgent advice!

Thanks

C.

[roccosmodernlife]

won't you still be covered by your warranty?

[Ebony ivy]

Hi all

I have a strange issue with my roc!

It happens at lower speeds (between 20 - 40 mph) when the car goes down an incline, it feels like the traction control cutting in, I cannot get the car to accelerate as the power is being cut.
Not sure if it's a VW / Audi thing, but an Audi A3 I had about 10yrs a go did the same thing, however, the 1 series I had prior to having the roc did not have this problem.

I've not tried driving the car with the traction control turned off, just thought I'd run it past the forum to see if anyone else has this issue.

Thanks in advance

Martyn

[Ramblas]

Hi Martyn, I've noticed the same thing (also have a TDI 170 incidentally). It seems to happen mostly when its cold and going downhill. Feels almost like engine braking but I have a manual and am not shifting down.

It's on my list to mention when I eventually have time to get into VW

[Ebony ivy]

Hi Ramblas, think I will go for a drive with the traction control turned off and see if it still does it, otherwise like you say could be one to run past the dealer.

Regards
Martyn

[RW1]

When you say downhill. Are you suddenly changing into a sharp down gradient like onto the far side of a hump back bridge effect at this speed?
Are you using a light throttle setting at this point?

C.

[Ebony ivy]

Hi RW1, yes it is that kind of situation when going over say the brow of a hill, not so fast as the front end goes light though, also not to dependant on throttle opening, can do it on light throttle openings or a heavier throttle. Any ideas?

Thanks in advance
Martyn

[Ramblas]

In my case I notice it mostly in the morning leaving my village on the way to work. The road I take is downhill and on the way down there is a steeper bit where this feeling always kicks in. Its about 100m outside the 30pmh limit so I will be steadily getting up to speed in 5th or 6th

[Ebony ivy]

Hi Ramblas, yup definately sounds like the same problem as I have got, the car is due for a service soon so will ask the dealer.

Regards
Martyn

[RW1]

Yes, its part of the Diesels 140 & 170 ECU programming. The effect is known and not a fault per say.

To do with the way the throttle works. Its the way the engine ECU monitoring is working to maintain engine torque. In the downhill phase, the torque is reduced to maintain the same throttle request from the accelerator pedal.

Normal behaviour for all VW diesels. No point going to the dealers with the effect. Nothing will be done.
You will also get it on undulating roads where you continuosly go up and down.

VW have no plans to change the ECU software.

C.

[Ebony ivy]

Hi RW1, many thanks for the reply It also explains why my Audi did the same thing, it sounds like something I will have to live with, not to worry.

Thanks again
Martyn