1.2 TSI chugging on acceleration

[Johnmarsh]

And of course I can just get a coil to eliminate it!

[xman]

Without error codes, its just a swap and try approach.

 

Could I suppose be fuel starvation, partly blocked fuel filter.

 

Or you might have a burnt exhaust valve (compression test to check)

Edited 11 October, 2018 by xman

[Johnmarsh]

yes ok.   Maybe as I have to go into town tomorrow I could keep getting car judder and see if it causes any fault codes.  When the happened to start with and i took it in to VW place they did originally say the fault code came up with spark plug one/lead.  So maybe they won't mind plugging in their diagnostic to see if anything else coming up this time?    I'll ask them as i did pay £130 for the repair which hasn't been resolved!  

Cheers

[Johnmarsh]

Went back to garage today to check what spark plugs they fitted and guy only had a part number but said they were from VW, so should be good.

 

I decided to go and see if they would refund me for their diagnostics as i had paid £127 (£38 for diagnostics) for work that hadn't been sorted.  The engineer said he wouldn't refund it as according to his diagnostics the problem had been sorted and therefore it was another issue.  So I put to him that it was very improbable that another fault has just appeared at the same time as he repaired it!  But he was adamant that when diagnostics pointed out that plug/lead one was shown as fault and that after he had changed plugs and that lead, that the diagnostics showed that the fault had been cleared and when he drove to test it it was fine.  But it has been an  intermittent fault as well anyway.  I can't see the logic in his answer considering that I still have the exact same problem regardless of what the diagnostics says!  It is the same issue I had when I took it in.

 

Anyway, can understand the difficulty of finding faults with cars even  for engineers but I couldn't agree with his answer.  So instead of any refund he has said to take it back in and they gonna have another look at it!  So I am happy with that and hope they find the issue this time!

 

I may still change the coil first, before I take it back just to eliminate that one, not sure yet.   I was thinking that how could it be the coil as it doesn't idle rough or there is no problem with starting and it runs smoothly and why would hard acceleration cause an issue if the car hadn't speeded up (higher revs), but then i saw this online which I didn't think about   " A weak spark is the first sign that the ignition coil may be failing. During acceleration, the air and fuel that is forced into the cylinders extinguish whatever spark there is, which causes the car to stall."   So maybe when i put foot down this could happen with more fuel going in and with intermittent break down of coil as well!    Anyway, you mentioned the coil so still a possibility among all the other things you guys have mentioned which I have a note of and gonna make sure I give the garage all the info. I can re how it judders or stalls (momentarily) but sure they'll check it first anyhow.... it will go in next wednesday so need to keep it running till then!!!

I also looked online and found and interesting video (no sound) about the tsi engine.  Sure you guys don't need to see it but I found it interesting to watch!

 

 

[Ootohere]

?

Can you explain, had they fitted spark plugs already

or have fitted them now, and is there no invoice with the part number you can tell us?

So because they were VW they would be right!

They will be if they are the correct ones, that is obvious.

[xman]

I would have ask for evidence they bought and fitted 4 plugs and not just one and got the part number.

 

From VW is not good enough, because VW has no access to Skoda service database for your car, so they will be just guessing.

Edited 12 October, 2018 by xman

[Johnmarsh]

Yes they had fitted all 4 new spark plugs (well I believe) and lead one when i took it to garage for the first time for the repair.  There is an invoice with cost listee plugs listed for 4 plugs but no details of what plugs they used.  After taking it back for refund the guy in office said he would have to ring them up to find out what the spark plugs were but he did affirm they were from Volkswagon parts.  Ok, I guess I'm truting they are proper parts.  I could, I suppose, take the plug leads off and check them myself, if i can see markings.  If they are all the same then they must have been changed and could see which spark plugs they are!!!

 

My question about them is the competence  of this garage (their technical/electrical -if its that)  to fix the car (as he kind of left me in the lurch about it and was going to send me off to Skoda without trying to sort it)  but I do feel they are trustworthy, but of course not 100% sure.  Is it easy to see markings on spark plugs if I  take leads off?

 

IWhen I take it back he has said he is going to keep car there for the day and if he can't find the fault he isn't going to charge me, 

 

 

[Johnmarsh]

Not sure yet if to change coil before going into garage wednesday.    If I do, I can get a Bosch ignition coil from europarts not too far from me.  But a question or two: 

Can I just swap it for the Bosh one?  Will it be accepted (if it has cpm built in?) by the cpu?  On that not, is the ignition side of things re coil controlled by small module cpm either inside the coil unit or is there another module somwhere or it it all controlled just by main computer cpu?

 

And if I do go ahead and do it I see it is suggested to remove battery connection first..... well, I'd rather leave it on as don't want to disconnect battery (don't know if that causes any problems with settings in cpu if disconnected?)  and I assume the only issue is getting a shock, but if the ignition is off guess that shouldn't happen or I'l be careful anyway!

 

There is a Haas coil but saw that they not so good and would go for Bosch and wonder what VW use? 

 

 

 

[xman]

Just plug and play. Which coil you buy is up to you, they all come with a guarantee surely.

 

Much cheaper from carparts4less.co.uk  which is the same company as eurocarparts £27 for HAAS version with discount code, £55 for Bosch. Often you can persuade ECP counter staff to price match carparts4less.

 

Cheaper options from ebay, amazon etc

 

[AMD87]

judder as in it feels like the engine is about to come off its mounts?

[bigjohn]

22 hours ago, Johnmarsh said:

Not sure yet if to change coil before going into garage wednesday.   

 

 

 

 

Just change the coil pack - they are not too expensive and a very common fail and a very easy fix. Symptoms are when you floor the throttle you drop onto two cylinders as the spark is weak on one coil (there are two coils within it feeding four plugs - which is why it's called a wasted spark coil pack). I have the same coil pack on my Octavia and it seems to fail every 8ish years. For some reason unless really bad (it gets worse and eventyually drops to two cylinders all the time) it doesn't always throw an error code. 

 

Get it sorted asap as everytime it drops to two cylinders neat petrol hits the cat!

 

Image below is when the coilpack failed for the second time on my Octavia 1.416v - well it is 17 years old now! Note the big holes bottom left. Saying that when the first one failed there was no physical signs. PS really easy job - pull off electrical connector and four ignition leads (note the positions) and undo 3 bolts. Took me a couple of minutes.

 

PS Yor money is not totally wasted on the spark plugs/leads (pardon the pun) - the fact it made a difference helping the weak coil pack showed they were probably past there best anyway.

 

This is a picture of the one I recentley took off my Octavia 1.416v - note the big hole bottom left!

 

Edited 16 October, 2018 by bigjohn

[Johnmarsh]

Ok, finally got coil from Europarts and thanks for mentioning the price match as they did Match Carparts4less at about £55 for Bosch which I decided to go for.... was going to let garage sort but last minute decision this morning to go up and buy it!!! 

 

Anyway, have fitted it now, and crikey, it's easier than fitting the HT leads!! on plugs....           

 

So, results so far on test run:    put foot hard down several times, and blow me socks off, not a single judder!   okay, I'm not going to get too excited yet as this has been slightly intermittent too so will have to see now how it goes when i go onto town tomorrow and back and thoroughly test it!    But at least i thought if  was taking it in tomorrow to garage then if I had changed the coil but still doing same thing they could then eliminate coil rather than waiting for them to order and try etc!!!!   But I've changed it now anyway!

 

If it goes well tomorrow morning without any hesitation I'll still take it to garage just in case I need any fault codes removed if any came up, as he wasn't going to charge for looking at it again anyway.   It was also interesting to note that there are two coils in the 'coil' and that one can fail!   So thanks for that bit of info too.   I've been looking up all kinds of info on this and trying to find out how the ignition system works and have learnt a little on the way.  I guess  I'm more wary of touching modern cars with computers or ecu's but in the old days I had no problem in finding electrical faults on distributor/ignition and HT side of things.  Anyway, this has given me a bit more confidence with my car at least at this simple level. 

 

I guess garages that  aren't that savvy on the diagnostics side (which must be quite specialist)  end up changing parts in process of elimination anyhow (though perhaps the more experienced ones have that ability to hear, feel, etc what is going on with engine to find faults).

 

Well, gonna keep my fingers crossed now and hope it stays good and will let you all know what happens in next couple of days.... and thanks guys for all your help, including last minute ones coming in on this!!!

 

 

[bigjohn]

Great stuff, think that's the last you'll have of that issue for a few years - just out of interest how old is your Roomster? Each of my coil packs lasted just over 8 years.

 

[Johnmarsh]

It's 2012 year so about 6-7 years old.....

cheers

 

[bigjohn]

9 minutes ago, Johnmarsh said:

It's 2012 year so about 6-7 years old.....

cheers

 

 

Have a spare to hand in a few years!

 

I'm not sure my old timer Octavia (well my sons now) will still be around then - saying that goes OK still

Edited 16 October, 2018 by bigjohn

[Johnmarsh]

Since I changed the coil it has been running fine after good testing and driving now!  So can relax a bit more now when out and about....

Thanks Guys.....