1.2 TSI Turbo Shim fitted

[Fred_Bristol]

Hi

Just had this done as part of the service at Platinum Skoda. I've found a few references to this, but not found any explanation of why and what difference it is supposed to make. ECU was also updated.

Can anybody point me to the explanation I've missed?

They also replaced the rear badge - even though there was nothing wrong with it (low mileage car that hides in a garage).

Happy New Year folks (better late than never).

Fred

[rafi_arch]

As far as I know it has to do with the "turbo lag" issue.

Myself I can confirm a difference between the test car I drove and our new received car, at least on the first hundreds of km.

After slowing down (before cornering or entering a traffic circle), mostly in 2nd gear, and trying to accelerate again afterwards - I could notice an engine lag (which is commented as "turbo lag"). This phenomenon shocked me at the very beginning, but now (after 11,000 km) either I got used to it and don't notice it, either it disappeared as the running in period of the engine is far behind.

I'm waiting for the 15,000 km service to know if our Yeti has to get that "service bulletin" (not a "recall").

As far as I know, the turbo starts operating at a certain predefined rev by means of the "wastegate", operated itself by an electric actuator (solenoid or a "step motor"). The shim alters the distance between this actuator and the wastegate in order to make the action more sensible or to start at a lower engine rev. Of course ECU has to be updated as mechanical changes can fool the computerized control. The wastegate itself controls the flow of the exhaust gases that powers the turbo - all gases can be wasted out, fully delivered to the turbo or something between.

Edited 17 January, 2013 by rafi_arch

[Ratz]

I had this adjustment almost a year ago.

The turbo effect is more gradual, and enters at 2000 rpm instead 1500-1600 rpm.

In a word, the motor is less diesel-like than before the intervention...

[andyspan]

I had this update done last May and can't honestly say I noticed any difference, perhaps it was too subtle for me! :think:

[rafi_arch]

In a word, the motor is less diesel-like than before the intervention...

Now that explains why that lag doesn't bother me...

Before the Yeti we owned a 63 hp atmospheric diesel Fiat Doblo.

At same car weight, the 105 hp TSI - even with the "turbo lag" - for what I was used, it can't be diesel-like !

Edited 17 January, 2013 by rafi_arch

[rafi_arch]

and enters at 2000 rpm instead 1500-1600 rpm

Ratz

Didn't you eventually mean that the turbo effect enters at 1500-1600 rpm instead 2000 rpm ?

To me it makes sense the turbo to take effect at lower rpm after the change.

Edited 17 January, 2013 by rafi_arch

[The Plumber]

Hi Fred,

likewise a happy new year

The turbo shim/ECU update was introduced for earlier 1.2TSI engines, as some owners where experiencing issues with their vehicle throwing up a EPC warning light and going into limp mode. This being caused by the operation of the servo actuated waste gate on the Turbo (the shim is on the actuator not the turbo itself); as I understand it anyway.

Our previous Fabia Elegance TSI 85 had this EPC light problem but only once. However bad timing, we were overtaking an HGV at the time thankfully we were on a downhill incline and with the aide of Isaac and the remaining power left in limp mode, we got past the wagon and dived into a convenient farm entrance :S An engine restart cleared the fault.

For us though the Turbo Shim caused all sorts of problems, in that the engine ran quite roughly and felt very sluggish for the next 2K or so after the mod was done. Dealer looked at it a couple of times but found no fault and they couldn't remove the mod either, Skoda wouldn't let them. SUK did say though that rough running could be expected in some instances, as the ECU was going through a relearning process but this should clear in about 500 miles. However as above it took over 2000 in our case and the engine never did seem quite right even after that.

Noticed our new Fabia Monte Carlo TSI 86, which replaced the Elegance, does not have the shim. Obviously a proper component update has been introduced, oh and the engine serial number configuration is quite different, so I suspect there's been quite some changes/modifications to the engine in the two and a quarter years since our first TSI was built.

Regards,

TP

[Ratz]

I confirm that my car is "gentler", now.

The effect of the turbo was not progressive before putting the shim: often I saw the ASR light on when accelerating hard in 2nd or 3rd gear on slippery road.

Now the engine is a bit more similar to an aspirated one and I have to manage it at higher revs; below 2000 rpm it is very weak, but in my opinion it is however a petrol unit which can arrive to 6400 rpm, so I am not concerned about it.

Ratz

Didn't you eventually mean that the turbo effect enters at 1500-1600 rpm instead 2000 rpm ?

To me it makes sense the turbo to take effect at lower rpm after the change.

[Fred_Bristol]

When the snow clears I shall be interested to see if there is any noticeable difference - I didn't detect anything during the 20 mile drive home.

If the modification reduces the momentary hesitation that sometimes occurs when pulling away from slow speed on entering roundabouts that will be good because the reflex action of pressing harder on the accelerator can produce a too quick approach to the back of a queue. (We have lots of roundabouts to which traffic lights have been added as an afterthought, but only to certain entry points.) I usually get round the problem by changing to S mode (DSG box) on approach when I anticipate a need a quick pull-away, seems to tell the ECU to get on with it.

Fred

[Expatman]

When the snow clears I shall be interested to see if there is any noticeable difference - I didn't detect anything during the 20 mile drive home.

If the modification reduces the momentary hesitation that sometimes occurs when pulling away from slow speed on entering roundabouts that will be good because the reflex action of pressing harder on the accelerator can produce a too quick approach to the back of a queue. (We have lots of roundabouts to which traffic lights have been added as an afterthought, but only to certain entry points.) I usually get round the problem by changing to S mode (DSG box) on approach when I anticipate a need a quick pull-away, seems to tell the ECU to get on with it.

Fred

Not sure when Skoda introduced the modification as standard but my March 2012 1.2 DSG doesn't seem to have a hesitancy problem, previously I drove a 2.0 Tdi DSG octavia and certainly you could encounter hesitancy - specially entering roundabouts - until you "learnt" to drive around it. Maybe I am automatically doing that with the 7 speed DSG but it just seems smoother than the previous 6 speed DSG (2005 vintage) on the Octavia. My wife certainly noticed the hesitancy when she drove the Octavia but hasn't mentioned any problems at all with the Yeti - and she would believe me!

[cackok]

The turbo effect is more gradual, and enters at 2000 rpm instead 1500-1600 rpm.

Noticed the same effect with mine...

[rog737]

Just recently had this mod done to mine. The car feels similar around town, but on the open road there seems to have a major performance drop. It feels less punchy - could be psychological but there is a long fast hill I regularly go up and had no problem climbing it in 6th before the mod. Now it is struggling to even maintain speed in 5th.

More alarmingly my fuel economy has plummeted. Averaged just over 40mpg from new and typically on a longer run would get around 45mpg. Had a run yesterday, aircon off, light winds and driving gently and could not get it above 35mpg on the maxidot

Edited 4 June, 2013 by rog737

[Zib]

Just recently had this mod done to mine. The car feels similar around town, but on the open road there seems to have a major performance drop. It feels less punchy - could be psychological but there is a long fast hill I regularly go up and had no problem climbing it in 6th before the mod. Now it is struggling to even maintain speed in 5th.

More alarmingly my fuel economy has plummeted. Averaged just over 40mpg from new and typically on a longer run would get around 45mpg. Had a run yesterday, aircon off, light winds and driving gently and could not get it above 35mpg on the maxidot

That suggests something wrong. Would recommend you take it back.