Noticed that the car (Fabia SE) is quite juddery at tickover when sat at a junction etc.

Strange thing is when you switch air con on and revs drop a little then its no where near as noticeable ?

Any ideas ?

mines the same. when sat at lights on a hill especially.

Mine did this a few times. I think It might have been a bad batch of fuel as its been fine ever since

mines the same. when sat at lights on a hill especially.

+1

The same here, defo worse when on a slope of some kind.

Its as if the car is misfiring slightly. Lumpy as hell.

I would love to know what it is that does this.

Lewwy

Sort of nice to know that mines not the only one doing it, was wondering if I adjusted the tick over revs up or down a bit that it might be better :S

sounds like Idle stabilization issue to me or maybe fuel pump doesn't like pumping up hill so much. Mine (not a vrs) used to dip then rise a little but I didn't worry about it, too much else to fix. My old Audi 100 needed a replacement idle stabilization valve but it was really erratic.

I think this has been raised before and it's something to do with meeting euro regs on emissions. The engine has a lumpy idle because the engine is being deliberately starved of fuel on idle, AC increases idle speed by a couple of hundred rpm and that solves the problem. If you are that worried, just leave the AC on all the time at the detriment of fuel consumption and stick 2 fingers up to euro regs and the environment.

Edited 12 April, 201115 yr by SkodaFabiaOwner

from reading lots of posts about this, it only appears to be the blt engine that suffers from this, i run bp ultimate diesel so not the fuel, i dont notice it all of the time tho, just occasionally, when on a slope for example. strange as hell lol

from reading lots of posts about this, it only appears to be the blt engine that suffers from this

My engine is the 1.2 HTP...

I have covered similar symptoms in previous posts/topics so here goes again!

Have to hand any security codes etc for radio etc as this involves disconnecting the battery!!!

Make sure that ALL devices are OFF eg interior fan set to 0 etc, as well as key out of ignition!!

Disconnect battery negative for about 40mins.

Reconnect battery.

Start engine and let idle for 30mins. DO NOT TOUCH CLUTCH, BRAKES, ACCELERATOR PEDALS ONCE YOU RECONNECT BATTERY OR THROUGH OUT THIS RESET PROCESS!!!

Turn of engine.....job done

The point of this is to wipe the learned values in the engine ECU and to reset to default factory, it then re-learns the idle values during the reset stage and the engine will sound as if its going to stall etc..this is normal!!!

I think this has been raised before and it's something to do with meeting euro regs on emissions. The engine has a lumpy idle because the engine is being deliberately starved of fuel on idle, AC increases idle speed by a couple of hundred rpm and that solves the problem. If you are that worried, just leave the AC on all the time at the detriment of fuel consumption and stick 2 fingers up to euro regs and the environment.

Thought switching aircon would reduce the revs by having an increased load ?

I have covered similar symptoms in previous posts/topics so here goes again!

Have to hand any security codes etc for radio etc as this involves disconnecting the battery!!!

Make sure that ALL devices are OFF eg interior fan set to 0 etc, as well as key out of ignition!!

Disconnect battery negative for about 40mins.

Reconnect battery.

Start engine and let idle for 30mins. DO NOT TOUCH CLUTCH, BRAKES, ACCELERATOR PEDALS ONCE YOU RECONNECT BATTERY OR THROUGH OUT THIS RESET PROCESS!!!

Turn of engine.....job done

The point of this is to wipe the learned values in the engine ECU and to reset to default factory, it then re-learns the idle values during the reset stage and the engine will sound as if its going to stall etc..this is normal!!!

Will give this a try at the weekend.

Interesting the guy I share an office with decribed his cars (VRS) behaviour at tickover as 'as if its about to stall !'

Will give this a try at the weekend.

Interesting the guy I share an office with decribed his cars (VRS) behaviour at tickover as 'as if its about to stall !'

The reason they sound as if they are going to stall is it's trying to set the idle speed...but if the learned values are not valid eg you have just but a new type of air filter in (basically anything that can affect the combustion process, it can even try to learn ontop of a learnt value) the ECU then can't cope 100% in all conditions...so you have to wipe the values and let it relearn again!!! It's like defragging your harddrive and rebooting from a fresh one!!!

The reason they sound as if they are going to stall is it's trying to set the idle speed...but if the learned values are not valid eg you have just but a new type of air filter in (basically anything that can affect the combustion process, it can even try to learn ontop of a learnt value) the ECU then can't cope 100% in all conditions...so you have to wipe the values and let it relearn again!!! It's like defragging your harddrive and rebooting from a fresh one!!!

How would I go about resting the ECU as you describe? thanks.

How would I go about resting the ECU as you describe? thanks.

About five posts up ^^^^ from this!!!

my wifes car is a VRS, that has lumpy tick over, unless you depress the clutch then it is smooth ??? assummed it was something to do with the dual mass flywheel

my wifes car is a VRS, that has lumpy tick over, unless you depress the clutch then it is smooth ??? assummed it was something to do with the dual mass flywheel

There are lots of things that can cause a lumpy idle...poor quality fuel..blocked fuel filter...cloged injectors etc etc...this is just one "free" easy first test to try to eliminate this possible known cause!!

There are lots of things that can cause a lumpy idle...poor quality fuel..blocked fuel filter...cloged injectors etc etc...this is just one "free" easy first test to try to eliminate this possible known cause!!

Just had the car serviced on sat, new air filter and fuel filter too.

Also just about to load up the new map from the shark group buy so is there any sense in resetting ECU ?

Just had the car serviced on sat, new air filter and fuel filter too.

Also just about to load up the new map from the shark group buy so is there any sense in resetting ECU ?

If you were not doing the remap then defo!!! I'm not sure if the remap completely wipes the learned values tho'...no harm in doing the "reset" is there?

Will give this a try at the weekend.

Interesting the guy I share an office with decribed his cars (VRS) behaviour at tickover as 'as if its about to stall !'

Did you try it then? How did you get on?

My missus has got this problem on her 1.2 Fabia 2, goes away when you switch the aircon on

Did you try it then? How did you get on?

My missus has got this problem on her 1.2 Fabia 2, goes away when you switch the aircon on

Yes I did it just before I uploaded the Shark remap.

Took it out for a quick spin after the reset stage and before uploading map and it seemed better (not as juddery at tickover).

However noticed last night that after loading the new map that it was back.

Worth a go on yours - as its only takes a coule of hours to do with very little input other than re-entering the stereo code.

Rob

If anyone feels this judder at idle is excessive, there is a check you can do with VAGCOM

Make sure engine is fully warm, and hook up your VAGCOM

Go to the Engine measuring blocks, group 4, and the 4th box over, it's name varies with VAGCOM version, but will either be called idle stabilization or Torsion Value. It should be in the -3 to +3 range, but preferably 0.5

If it's way off, the Crankshaft to Camshaft timing is incorrect, most likely due to a timing belt change that has been done wrong.

The belt wont be a tooth out or anything as severe, but the camshaft outer pulley that the belt runs on, may not be aligned correctly.

The 3 bolts holding the pulley to the camshaft timing hub, are slackened during belt fitting, and as the belt tensioner is adjusted, the cam pulley moves slightly (as it should) and the tensioner is then tightened, and then the three sprocket bolts.

The engine is then turned through two revolutions of the crank to TDC, and a check made to see if the crank and cam locking tools can still be inserted.

A good garage will then check the Torsion Value with VAGCOM to make sure it's withing spec.

A common error when fitting timing belts, is to set the belt tensioner pointer in the middle of the adjustment slots AFTER the tensioner bolt has been tightened. The pointer will in fact move clockwise about 5mm at the tensioner bolt is tightened to the correct torque. This should NOT be corrected, as the belt will settle in slightly after a few hundred miles.

A simple check, is to remove the top timing belt cover, and check if the three camshaft sprocket bolts are in the middle of the elongated slots, if they are not, your crank to cam timing will be out.

Note that BLT engines do tend to shudder slightly at idle due to emissions settings. If it's bad however, get the timing checked.

If anyone feels this judder at idle is excessive, there is a check you can do with VAGCOM

Make sure engine is fully warm, and hook up your VAGCOM

Go to the Engine measuring blocks, group 4, and the 4th box over, it's name varies with VAGCOM version, but will either be called idle stabilization or Torsion Value. It should be in the -3 to +3 range, but preferably 0.5

If it's way off, the Crankshaft to Camshaft timing is incorrect, most likely due to a timing belt change that has been done wrong.

The belt wont be a tooth out or anything as severe, but the camshaft outer pulley that the belt runs on, may not be aligned correctly.

The 3 bolts holding the pulley to the camshaft timing hub, are slackened during belt fitting, and as the belt tensioner is adjusted, the cam pulley moves slightly (as it should) and the tensioner is then tightened, and then the three sprocket bolts.

The engine is then turned through two revolutions of the crank to TDC, and a check made to see if the crank and cam locking tools can still be inserted.

A good garage will then check the Torsion Value with VAGCOM to make sure it's withing spec.

A common error when fitting timing belts, is to set the belt tensioner pointer in the middle of the adjustment slots AFTER the tensioner bolt has been tightened. The pointer will in fact move clockwise about 5mm at the tensioner bolt is tightened to the correct torque. This should NOT be corrected, as the belt will settle in slightly after a few hundred miles.

A simple check, is to remove the top timing belt cover, and check if the three camshaft sprocket bolts are in the middle of the elongated slots, if they are not, your crank to cam timing will be out.

Note that BLT engines do tend to shudder slightly at idle due to emissions settings. If it's bad however, get the timing checked.

Ours started juddering after it went in for a timing belt change and after seeking advice on here I took it back for them to check it'd all been done right, supposedly it has. However, its still lumpy at tickover, a lot more so than went it went in and now with this hot weather its even worse.

They told me that one of the injectors was under-fuelling so they upped that, it didn't fix the issue.

It is about time it had an oil and filter change, beyond that is there any thing that I can do to strongly suggest they check the timing belt?

Edited 27 June, 201115 yr by Paul Bennett

Ours started juddering after it went in for a timing belt change and after seeking advice on here I took it back for them to check it'd all been done right, supposedly it has. However, its still lumpy at tickover, a lot more so than went it went in and now with this hot weather its even worse.

They told me that one of the injectors was under-fuelling so they upped that, it didn't fix the issue.

It is about time it had an oil and filter change, beyond that is there any thing that I can do to strongly suggest they check the timing belt?

If they have checked the syncro angle and it's within tolerance, the next check would be to pull the rocker cover and check the camshaft and bucket tappets. Revised bucket tappets are case hardened and black in colour. If they are OK, sometimes increasing the idle speed to 900 RPM fixes it (didn't on mine.) Other things to check, engine mounts and rear gearbox steady dogbone mount. Fitting a Mahle air filter can fix it.

I am still trying to figure out why even correctly done timing belts can cause this issue on some cars.

If anyone feels this judder at idle is excessive, there is a check you can do with VAGCOM

Make sure engine is fully warm, and hook up your VAGCOM

Go to the Engine measuring blocks, group 4, and the 4th box over, it's name varies with VAGCOM version, but will either be called idle stabilization or Torsion Value. It should be in the -3 to +3 range, but preferably 0.5

If it's way off, the Crankshaft to Camshaft timing is incorrect, most likely due to a timing belt change that has been done wrong.

The belt wont be a tooth out or anything as severe, but the camshaft outer pulley that the belt runs on, may not be aligned correctly.

The 3 bolts holding the pulley to the camshaft timing hub, are slackened during belt fitting, and as the belt tensioner is adjusted, the cam pulley moves slightly (as it should) and the tensioner is then tightened, and then the three sprocket bolts.

The engine is then turned through two revolutions of the crank to TDC, and a check made to see if the crank and cam locking tools can still be inserted.

A good garage will then check the Torsion Value with VAGCOM to make sure it's withing spec.

A common error when fitting timing belts, is to set the belt tensioner pointer in the middle of the adjustment slots AFTER the tensioner bolt has been tightened. The pointer will in fact move clockwise about 5mm at the tensioner bolt is tightened to the correct torque. This should NOT be corrected, as the belt will settle in slightly after a few hundred miles.

A simple check, is to remove the top timing belt cover, and check if the three camshaft sprocket bolts are in the middle of the elongated slots, if they are not, your crank to cam timing will be out.

Note that BLT engines do tend to shudder slightly at idle due to emissions settings. If it's bad however, get the timing checked.

Hello MoggyTech and others,

My Fabia VRS le has, over the last month or so aquired a judder as you describe at idle, I don't have access to VAGCOM to check the Torsion value you mention, but my son has just checked the timing today and has checked and double checked everything he can the only thing hes done is very slightly adjusted the position of three sprocket bolts in the top camshaft pully ie slightly more towards the central position you mention in your posting and for now the judder is gone.

My question is should these three bolts really be replaced with new ones ? ie are they stretch bolts ? and what torque should they be re-tightened to ?

Thanks in advance for your replies.