Octavia VRS "pulses" on low rpm and sluggish pedal response

[Snu]

Is any body else having the same problem !!!!!

I've had the injectors and new loom done on my 07 VRS 170 but ever since I've noticed that at a steady speed the car feels like it's pulsing, almost like it has air going through the injectors and giving a reduction in power for a millisecond, it also has a little stutter when you press the throttle as well.

I've remapped the car and it's still the same, I also have a map ready to load when I remove the insides of the DPF and weld it back up but I really need to sort this problem before I move on to do that.

If I took it to a garage I would struggle to get the machanic to under stand what I mean as it only a very slight thing......just like driving on a slightly uneven road with slightly stiffened susspension, more of a niggle than anything else.

[fabio978]

I think i have a similar issue on my VW Golf 4.. i didn't get it sorted yet.. :think:

[H11nta]

i have the same problem with mine i have been told it is the diaphragm in the vacuum solenoid.

But when i phoned skoda they did not know what i was on about so i will take the car down to them next week

[H11nta]

i have been told to change this but no one seems to know what it is i have been told it has a split diaphriam.

[Snu]

Thats the swirl flap actuator, it works on vaccum to opperate the swirl flaps inside the inlet manifold, you can check for a split yourself, just get a piece of tube the same diameterand attach it to the actuator and suck on the tube, once you've moved the are by suction place your tounge over the pipe and see if the arm moves back, if it does then the diaphiam has a leak and you need to replace.

[H11nta]

Hi thanks could this leak soot thats what I am getting . Or could that be a seal ?

[Snu]

The actuator only moves an arm which opens up the swirl flaps, the most likely cause is the bar that runs through the inlet manifold is probably worn, I had this problem on mine and it's not a cheap fix £365 + vat just for the inlet manifold plus fitting so make sure it is that before you blow your cash.

[H11nta]

oh no i hope it not that. do you have a part number?

[Snu]

Part number for mine was S03G129711as, all you have to do is ring them with your reg number and they will know which inlet manifold you have.

[H11nta]

So you have to replace to whole manifold. Could you not just replace the bar?

[Snu]

It's moulded and you can't split it, have you tried the suction method to see if the diaphram is leaking !

[Awesam]

I've got the same problem, however if I floor it in 2nd gear or below 2000rpm in 3rd the car kinda chokes before it picks up speed.

[Awesam]

The actuator only moves an arm which opens up the swirl flaps, the most likely cause is the bar that runs through the inlet manifold is probably worn, I had this problem on mine and it's not a cheap fix £365 + vat just for the inlet manifold plus fitting so make sure it is that before you blow your cash.

Was that from a main dealer or an independent garage?

[drefaldwyn]

I have a similar situation with my lightly remapped 105PD - hesitation on gentle acceleration between 1500 - 2000 rpm but this has only occurred since the remap which was done over 3 years ago. It's not too troublesome so I guess I've kinda learned to live with it. The strange thing is that it only occurs when the ambient temperature is over about 12 deg C. In winter it's fine.

If I put my foot down a bit the problem disappears. Strange!!!

Any ideas?

Best regards and thanks in advance,

Dave

[Dogsnob]

i've also experienced this problem. only at low speeds and only when the engine is warming up. seems to run fine when it's up to temperature. it only started after i had the loom and injectors replaced. i had DM Keith in Leeds look at it but they could not find a fault....funny cos i notice it every day.

[fartingfury]

I've been getting information from this site for years, so now that I have some information myself, it seems only fair that I finally sign up and share!

Have been experiencing this stutter for a few months - usually when I put the foot down in 5th at 80-90km/h. Also had the "soot leak" (soot on alternator, soot around the swirl valve actuator) and a slight reduction in fuel economy (45-ish MPG on a run to the mountains instead of 50). The car has had the injector recall but that was almost two years ago so I don't think that it's related.

Took the intake manifold out: What is happening isn't actually wear on the bar. The end of the bar is attached to an arm, the end of which is attached to the axle that the swirl-valves are mounted on. So as the swirl-valve actuator goes in and out, the swirl valves are opened and closed. The axle-to-arm joint passes through a seal, to keep the turbo-pressure contained inside the manifold. This seal had popped out, hence the soot and, I assume, the pulsing - perhaps as the turbo spools up at low-ish RPM?

I couldn't find what was supposed to be holding the whole bar-arm-seal assembly in place but I have the feeling that it was just a tiny plastic lip and that it has long since been worn away. Plus, one of the swirl valves was missing a few little chunks where it meets the axle, so with these two defects, I decided to err on the side of caution and buy a new one: €500 (incl new seals) from a website called Autohaus Plaschka (Incidentally, if you use them, include your mobile number to help the less-than-amazing delivery company). The manifold has been re-designed with a new metal plate extending alongside the arm so that it can't escape too far - presumably VAG noticed that these have been failing plenty.

Not an especially difficult job as long as you don't forget that there is a bolt hidden in the crud inside the intake of the manifold. The crud build-up was about as bad as the second set of photos here: http://www.briskoda....valve-cleaning/ (have 70k miles) so I cleaned it out some, but not nearly as well since it's only going to be filthy again in a week or two. Had to manhandle the crud-supply pipe to get at one of the EGR bolts but it seems to have survived.

While I was there, I fitted one of these: http://www.briskoda....problem-solved/ more for its anti-crud properties than its anti-stutter properties.

Anyway, practical upshot is that the stutter seems to be gone.

Edited 21 June, 2013 by fartingfury

[greatdane]

mine does this on it start up normally in 3/ 4 gear when cold but soon as its warm it goes away!

was hoping it would go when dpf is out and been sharked but will have a word at shark when I take it in for remap and dpf out.

Unless its the 14stone "thing" in the boot weighing car down