1.2 TSI chugging on acceleration

[Johnmarsh]

My roomster went to Vw garage (small dealer)with engine problem: when I accelerate hard it really starts chugging or pulling back.  Not like it's running on 3 cylinders but like it's just no power in it when the chugging happens.  The garage  found fault and replaced all spark plugs and plug lead 1.  Since they done it it's better but if I put foot down hard it starts the chugging again!   Spoke to mechanic who plugged in fault finding gear (vcds I think) but no fault found.  Mechanic did say Possibly turbo problem or other plug leads... So, stuck with problem.  Just wondered if anyone out there with any ideas as not sure how confident I am with garage ability to diagnose or maybe if nothing comes up on diagnostics there's no way of knowing!

cheers

John

[Ootohere]

Odd that a VW Technician should not know what is what.

Maybe first day at the job, or a Skoda badge causes memory loss.

 

There is a TPI, there is a lead upgrade, a lead with armouring.   So the VW Trained technician should know that, not just think it.

 

The Technician should also know about the Turbo Shim and the TPI on that and the Turbo Actuator issues.

Hopefully knows about timing chain tensioners as well.

 

Protected lead threads in various sections around Briskoda.

http://briskoda.net/forums/topic/273839-tpi-ht-lead-failure

 

Edited 24 September, 2018 by Offski

[Johnmarsh]

Ok, if he doesn't know at least i do now!  My concern is taking it back and the garage changing several parts until finally they get to the right thing!  Years ago on my old cars i used to fix the igniton system myself  when eg faulty ht leads, or points etc as have an electrical background,  I wouldn't usually touch a modern car because they so computerized and codes etc...... but just wondering if I could get some cheap  working second hand leads I could change some to see if  it fixes it?  If it is something on ht side then I guess it can only be leads (not spark plugs now as they have been changed)  or  the coil.   Am driving car and its ok but only when I put foot down does it start juddering.  Since garage changed that lead and plugs it is better than it was (as before it seemed like it might cut out completely) but obviously still there when the engine pressured.  Thanks for the link as I have looked through and can see there is an issue with some leads.

I think I paid about £18 for plug one lead so they are quite expensive!  Anyway, just thinking if I can try anthing myself to at least eliminate leads even if they arnt the problem and save a few quid.  I will check tomorrow also to see if any other leads are burnt near engine...

Cheers

John

[xman]

If its an ignition problem (likely) then its usually no.3 lead that goes first, I would say almost always. It could be and probably is already faulty (the internal core breaks and goes open circuit because of excessive heat from the exhaust shield it sits over, but sparks over internally,  gradually getting worse until either misfiring occurs or the ignition coil fails)

 

You can buy a complete set for under £50. For example these NGK 44316 lead kits (who are the OE supplier to VAG of 1.2tsi plugs and leads) are the latest style with 'marten protection' what offski refers to as armouring.

 

Cartech (whoever they are)

 

Or

 

Amazon

 

It takes less than 10 minutes to change all four, but you do need a spark plug lead puller such as this

 

Sealey VS5293 lead puller

 

Heres a pic of a 1.2 tsi without marten protection (corrugated trunking) on the leads

 

 

 

and one with marten protection

 

 

Don't worry about the different plastic covers/holders with TSI on them that's cosmetic. The corrugated trunking is located forward of the "TSI" cover. Just be aware that no. 1 & 2 leads clip to the stainless steel pipes that run along the front of the engine. New larger clips supplied in the kit, make sure they're fitted otherwise the lead trunking ends up resting on the hot exhaust cover and melting.

 

A turbo fault would most likely throw errors and put your engine warning light on. It also wouldn't judder, just lose  power and almost always go into limp mode. So I don't think its that.

 

 

Edited 25 September, 2018 by xman

[Johnmarsh]

Thanks so much  for that info!  Will get some leads sorted and a puller!

[Johnmarsh]

Have replaced the other 3 leads now and although it seems 'better' when i put my foot right down hard it pulled back again!  So not sure if I'm imagining it  is pulling better after changing ignition leads or if its the same!  It seems fine if I drive it without putting my foot down, so perhaps that's the answer!  When it was wet the other day it was worse and really pulled back a few times when accelerating (not that hard either).  But I just went out for a spin and put my foot down a bit and thought I'd cracked it until I put the engine under more pressure by accelerating in third gear when not so high revs, hence putting more pressure on it.  I have just looked at the coil just in case there was any tracking (of the high voltage) around any of the plug connections, but can't see any.  I guess it could be the coil?  

 

Was trying to put my electrical brain on this one but wondering why it would pull back (judder) only when putting foot down hard when I hadn't yet speeded up or the coil wasn't at that moment of acceleration producing any more high voltage to leads.  Would imagine coil or leads to be prone when coil delivering more when engine revs higher but then I don't understand the modern electronic systems, unlike the old days with distributor cap, could fix all that stuff! 

 

My concern is taking it back to the garage and them not working it out either, as they only rely on the diagnostics, which according to my small VW dealer, said that after they changed plug one, the fault was resolved (on diagnostics) but of course it wasn't!  It could cost me a fortune (so far diagnostics and change of plug lead one £130) if they change bits until they finally get there! 

 

Offski did mention some other issues such as turbo shim/actuator issues and timing chain tensioner.   Keeping in mind that the car runs fine until hard acceleration - could it be the turbo then or timing chain tensioner?   Xman mentions that " A turbo fault would most likely throw errors and put your engine warning light on. It also wouldn't judder, just lose  power and almost always go into limp mode. So I don't think its that. "  My car hasn't gone into limp mode or no warning lights yet!  And do turbo faults ever judder? Or pullback suddenly under hard acceleration?

 

Anyway, I know no one can properly diagnose the isse here but just appreciate any more feedback or ideas.   Perhaps it's back to the garage for further investigation or maybe i should wait until it goes completely when driving....though as I said it drives fine but only until I accelerate hard.

 

Thanks to all contributing here...

 

 

 

 

 

 

[Johnmarsh]

Just one more thought:  the pollen filter hasn't been changed for couple of years, could that cause car to judder if it needs changing?

 

[Ootohere]

No, because that is a Cabin filter, for the people in the car.

 

Air Filters and Fuel Filters affect the engines good running.   Have these been changed or the Air Filter looked at?

[xman]

1 hour ago, Johnmarsh said:

Just one more thought:  the pollen filter hasn't been changed for couple of years, could that cause car to judder if it needs changing?

 

 

Lol (is this a serious question?)

 

No! The pollen filter is there to stop dead flies and such being blown out the air vents into your face when you turn on the fan!

 

How old is the fuel in the tank? If you don't top up the tank very often, say at least once a month, the petrol can go off and lose Octane rating especially if its standard unleaded, when the ethanol content and lighter fractions evaporates. Leads to running issues like you describe. Topping up with super unleaded will restore/refresh the fuel.

 

There may be water in the fuel , topping up with fresh fuel will help reduce it.

 

The ignition coil may have been damaged when the lead/plug failed, and may be weak. Unfortunately the only way to check is to swap it with a known good one.

 

Pulling back or juddering? Which is it? Juddering is synonymous with misfiring. Pulling back or losing power without juddering may be turbo related, but often that triggers limp mode. Or do you mean, momentary hiccup in power delivery (isolated misfire).

 

Oh and another thing, check the plug leads are pushed right down onto the plugs, quite a tight fit.

 

Finally check they fitted the correct plugs 

NGK LASER IRIDIUM Spark Plug IZFR6P7 (original fit)

Or

BOSCH Iridium Spark Plug 0242240665 

Edited 4 October, 2018 by xman

[Johnmarsh]

Hahaa, always thought the pollen filter was the engine air filter!   But at least i know now!   It did have a small service in sept with oil change but not sure what else.  Can't see anything else changed in service book.  "Air Filters and Fuel Filters affect the engines good running.   Have these been changed or the Air Filter looked at?"    So fuel filter not changed and will check tomorrow if they change air filter on small service. 

 

Re misfiring or juddering:       perhaps its as you describe - "momentary hiccup in power delivery (isolated misfire). "    When I tried it today I only allowed it to do it once because I pulled off the hard acceleration.  But when I did it before (a day or so ago on rainy morning) it  'misfired' as just pulling in second gear from low revs and seemed jittery as i accelerated (a new word!) so went to work not accelerating hard and was ok  so I'd take foot off accelerator and just allow it to pick up slowly. 

 

If I drive it up a hill I can keep the throttle as it is and car will of course slow down but without juddering so i then just change to lower gear.  I guess the word judder seems useful if I've not taken foot of accelerator and it tends to stop start (its never cut out yet though). 

 

I havn't really kept my foot down for too long as not sure if the car gonna suddenly go altogether on me or damage anything.  The VW dealer did say, before he changed lead, that it was best not driven in case it had an adverse effect on the (I think) catalytic converter, something about unburnt fuel (if remember that right).  before I had the lead done at garage it did seem worse and after doing the leads today it seems better than it was.  But I'll have to drive it a bit more to find out for sure.  Or it could just be coincidence!  Anyway, will go in to work tomorrow about 10 miles (car gets used regularly) and see what happens!

 

I guess without your expert ears listening to it or feeling what is happening, i can only describe as best I can what is happening. 

 

Have taken note of spark plug info thanks and possible coil and pretty sure plugs are snug in but may get garage to double check them. 

 

 

 

 

 

 

[xman]

Any way you can check all the plugs have really been changed, did they give you the old ones back?

 

Is the fuel fresh?

Edited 4 October, 2018 by xman

[Ootohere]

?

What age is the car, and how many miles done?

 

Sorry if that is in the posts, but i missed reading that if it is.

[Johnmarsh]

Age of car is 2012 and mileage is 60,000.  Fuel us fresh as topped up early yesterday and buy around £35 fuel per week.  They didn't give old plugs back but do trust them in terms of honesty.  Knowing how good they are technically though I'm not sure.  Anyway drove 10 miles this morning and from cold it 'juddered' a couple of times on light acceleration but seemed better as warmed up a bit.  The only things I could do by myself now is changing air filter and coil.  But just have that gut feeling that it will be the same.  Will go back to have chat with local small Vw dealer first.  One limitation with them is that their diagnostics is more limited than the main big Skoda dealer whose diagnostics can extract codes unlike the small Vw guys.  But the Vw garage is half cost labour!   Another but though: about a couple of years ago the steering went on car and took to main Skoda dealer who diagnostics said it was faulty steering pump. Well because out of warranty  (2 weeks!) I had to past and it was around £900 plus £120 diagnostics.  So I got decent low mileage car 2nd hand one and another garage fitted it.  (By the way steering fault intermittent) anyway they couldn't get rid  of warning light.  So I decided to go to another Skoda main dealer who had it for a week to try and find problem.  It turned out that it was a broken wire after all and new dent of changed pump!  So, I'm also reluctant to take it to my main Skoda dealer.  My earnings are quite low which is why I end up getting anxious about car repairs and trying to find most cost effective garage, even if they charge more but st least diagnose it quicker before changing a heap of parts that could cost a fortune.  Maybe I'll take out some warranty!

cheers

[Johnmarsh]

Just been to the small Vw garage and he suggested I take it to main Skoda dealer.  So that eliminates that one!

[Johnmarsh]

update:

 

just found another small local  vw dealer and chatted with him.  He plugged his diagnostics in and said for me to go out on drive so he could record fault.  Well, guess it's sods law that nothing happened!!  Put my foot to floor which usually does it....but was fine, best so far!    So no fault recorded!  The only thing different i did before driving up there was to just wiggle connections around engine including the feed to coil.  So I wonder if it was just a 'loose' connection ?   If it is it could save me several hundred pounds!  The vw guy at this other garage seemed a lot more keen to asses what was happening unlike my previous garage who didn't seem to want to pursue the issue with my car. 

Anyway, will be doing some distance over weekend and will see what happens and if the fault comes back or not!   Will keep you guys updated early next week when back and thanks for all the info so far......

 

[Ootohere]

The Spark Plug and Air Filter change intervals according the the Manufacturers Guidelines is a 40,000 miles / 4 years.

 

So either done or not, but anyone charging for diagnostics should have opened the Air Filter box and looked.

& an Air Filter is £16.

 

Removed the spark plugs and checked, and since out as well to fit new ones with the pre gapped gap checked.

 

It is basic stuff, then you have an idea what you are dealing with.

[Ootohere]

So has the car been checked via the VIN to see if it was one that should have had the Turbo Shim mod, or is that just for earlier cars.

What about the Turbo Actuator issues, there have been cars after 2012 with that problem, when a warranty owners told it needed a new Turbo as actuators where  not available, on back order, difficult to fit etc.

As it is readily available and a tech / mechanic that can be bothered fits them with no problems.

 

http://briskoda.net/forums/topic/445168-12-tsi-charge-pressure-control-actuator-epc-fault

 

Edited 5 October, 2018 by Offski

[KenONeill]

1 hour ago, Offski said:

Removed the spark plugs and checked, and since out as well to fit new ones with the pre gapped gap checked.

I guess by this you mean that, even if fitting "pre-gapped" plugs you should always check the gap?

[Ootohere]

You say it differently from me but you seem to have known what i ment.

So exactly what i meant, check the gap and then put the plugs in carefully.  Also check all 4 plugs removed to see what they were at for the gap.

[xman]

4 minutes ago, Offski said:

You say it differently from me but you seem to have known what i ment.

 

[Johnmarsh]

On 05/10/2018 at 13:47, Offski said:

So has the car been checked via the VIN to see if it was one that should have had the Turbo Shim mod, or is that just for earlier cars.

What about the Turbo Actuator issues, there have been cars after 2012 with that problem, when a warranty owners told it needed a new Turbo as actuators where  not available, on back order, difficult to fit etc.

As it is readily available and a tech / mechanic that can be bothered fits them with no problems.

 

http://briskoda.net/forums/topic/445168-12-tsi-charge-pressure-control-actuator-epc-fault

 

Don't know if my 2012 has had turbo shim mod.  Did check your link and noticed it said problems here can cause delayed power to engine.  The problem i'm having is not delayed power but an on and off power which makes it judder under acceleration.  It kind of jolts back and forth whilst i have the accelerator pushed down a bit.  Would an actuator or turbo fault make it judder like that? 

 

After last weekend and longer drive it seemed completely fine!  Until, that is, this last Tuesday, just after starting up and leaving home, it did its juddering thing even with low pressure applied to accelerator, so as usual, I backed off accelerator and it was ok.    After being parked up for about 4 hours and also had quick look again under bonnet and just checked electrical connections drove off with no problems at all.  So, think next time I start up engine will try it to see if it seems to be only happening from cold or i suppose it is possible there could be a loose connections on wiring (or broken wire) around engine.  That's what happened when my steering pum was diagnosed as faulty some time ago but it was actually a broker wire!  

 

there's no engine light on, perhaps because I havn't allowed it to judder extensively. 

Re spark plugs:  I would have thought the VW guy would have made sure that ok....... and I don't have a way of removing it or checking myself.  I was only going to get involved with leads or wiring.....

 

Well, at least there is one conclusion so far:  it is an intermittent fault!

It makes me wonder what effect a loose connection (or bad connection) would have on engine.  guess if it was supply to coil it would judder if the wire or connection is making (most of time) then breaking occasionally.  If it was only one HT lead, i assume it would 'misfire' more or just feel like it's running on 3 cylinders for a mo?  Like in the old days with my older cars/bangers......     Or i wonder how the computer works?  Whether it senses something/fault and then cut the electrical  supply to  coil (to shut down engine) but then would it not go into a limp thing?  Would one cylinder/lead problem cause it to feel like all the power has gone momentarily or perhaps that feels like the either the coil at that moment has broken down thus no spark to any cylinders?  Or perhaps as a low voltage problem connection....or would any sensors on the engine that  are becoming faulty cause that momentary judder....I don't know how these things communicate to the engine computer!   And I wonder even if that could be an issue...don't know how reliable they are....

Just one other thought: the VW dealer mentioned one other thing that it could be and said possible injector?  So would on injector problem cause that judder? or feeling that all the power has gone for a fraction of a moment......

 

If it is a wiring problem then it could be difficult to sort, because the last time re pump wiring took Skoda dealer a week to find it as the master Tech couldn't find it himself but only after corresponding with the Skoda manufacturers themselves did they finally find it?  The real funny thing about all that was i had a hunch it may have been the wiring as all that happened on a precious car!!!

 

 

 

Will try it shortly to see what is happening today?

 

 

[Ootohere]

So the Spark Plugs need removed and checked, or ask the person that should have if they did.

 

Anyone that removed Ignition coils had done the first bit, 5 more minutes and the Spark Plugs are out. 

Edited 11 October, 2018 by Offski

[Johnmarsh]

That was meant to say "previous car" lol.

 

[xman]

Yes check all spark plugs were changed and for the right type.

The ignition coilpak is a 4 coils in one, single item supplying all 4 plugs. Its possible it has been compromised by the previously/lead problem, tracking internally and weak spark.

 

Easy to change part no 032 905 106 B/D/E  E is the latest version

 

Available from usual places, eurocarparts, gsfcarparts, eBay, amazon  etc seen them for under £20 new.

 

Edited 11 October, 2018 by xman

[Johnmarsh]

Right just went for drive from cold and its doing the judder thing.  So I let it warm up a bit for about 10 mins on drive and tried again.... still doing it so can't be anything to do from cold.  As I kept putting my foot down seemed to be getting slightly worse.... wonder if its better to do that and make it go completely?  But it may mean I get stuck on the road somewhere!

I can check tomorrow morning what spark plugs they fitted. 

 

Just some other feedback;  if I put my foot down hard on accelerator when car in neutral standing still it seems fine, so it seems to be doing it when foot is hard down and engine under bit of pressure.  When I tried it today it seemed fine on light acceleration so had to put foot max down this time to get it to do the juddering and then started getting bit worse, so not sure if that indicates anything else?

 

If there is a problem with the HT side of things would I not get some 'misfiring' or judder when the accelerator is hard down or not?  As, when I put my foot down the car hasn't at that time speeded up so engine not at any higher revs and it can cruise at 70mph again with no judder....  I would have thought if there was an HT issue that the problem would occur at higher revs when the coil is under more demand and trying to feed those spark plugs?  I assume the coil has greater stress at higher engine revs?  And the leads and plugs too?    Although to be accurate here if i put my foot hard down it doesn't happen instantaneously as, for example, I may be  doing say 10mph and put foot hard down and ok for a second or two but then the judder kicks in at say 20mph maybe in second gear or in third.   I am putting extra stress on engine (wouldn't normally put foot down like that from such low speed in 2nd or third) .  But I'm sure when problem originally happened it juddered immediately when I put foot down.  Phew, this is perplexing!