Juddering under load after spark plug/ignition coil replaced

[PraiseTheSun]

Morning all,

My 2010 Cupra was having issues last week with engine juddering, due to the famous engine misfiring issues.
The fault codes were for multiple misfires on cylinder 2.

My garage went ahead and changed the spark plugs and coil pack.

This seemed to fix the issue for about day, and now the check engine light is coming on again and the juddering is even worse than before. It seems to be about 4,000 revs when driving hard, but not always.

There doesn't appear to be any smoke or any whine from the engine, it just kinda judders and loses power for a moment.

Any clue what could be going on here? Thank you.

 

[everson38]

Morning all,

My 2010 Cupra was having issues last week with engine juddering, due to the famous engine misfiring issues.
The fault codes were for multiple misfires on cylinder 2.

My garage went ahead and changed the spark plugs and coil pack.

This seemed to fix the issue for about day, and now the check engine light is coming on again and the juddering is even worse than before. It seems to be about 4,000 revs when driving hard, but not always.

There doesn't appear to be any smoke or any whine from the engine, it just kinda judders and loses power for a moment.

Any clue what could be going on here? Thank you.

Do you know what coil pack they used. I've heard after.market can cause issues and better to buy OEM or at least what ever brand was in originally

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[RUM4MO]

Personally, I'd avoid putting that engine into the "zone" that is causing it to misfire as you just end up forcing itself to trash itself, is that not the rev range where both the supercharger and turbo are "working"?

Are you using a garage that understands these fragile engines?

 

[PraiseTheSun]

Hi, thanks for the replies.

Sadly, I do not know which coil pack brand they used.

The "zone" seems to be around 4,000rpm which I can avoid if I drive slowly.

I do trust my garage as I have been going to them for almost 10 years with 4 different cars, but I'm seeing these engines are special snow flakes.

There is a Seat "specialist" in my town, but since they told me my DSG oil never needs to be changed, I don't think I trust them.

Would you recommend going through the actual Seat dealership?

 

[everson38]

Hi, thanks for the replies.

Sadly, I do not know which coil pack brand they used.

The "zone" seems to be around 4,000rpm which I can avoid if I drive slowly.

I do trust my garage as I have been going to them for almost 10 years with 4 different cars, but I'm seeing these engines are special snow flakes.

There is a Seat "specialist" in my town, but since they told me my DSG oil never needs to be changed, I don't think I trust them.

Would you recommend going through the actual Seat dealership?

Yes I would consider seat. I know annoying as they will be more expensive but they should be more clued up. U may want to try find out what parts was put in hour car first from ur garage to have full picture. But then seat maybe next option. Have u looked at all using that affect air circulation. Dirty air filter. Is your maf sensor attached properly? (I actually forgot to screw on my fiance on her corsa) so can be done lol. But no harm in taking it to set just for a diagnosis and then come back here to see what people think.

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[RUM4MO]

It is a bit annoying if you can't/don't trust your local SEAT dealership, but you should contact them about this and find out what if any repair work/upgrades have already been carried out on that engine so that you know what the next step is. If you feel that getting some redress from SEAT UK is possible, using a SEAT dealership to do the initial investigation should be essential, though once the engine has been opened up, if it comes to that, then you would need to fight SEAT UK in respect with getting any help sorting out this engine as it could be that it is well on its way to self-destructing - if what I suspect is going on inside that engine.

Remember that I and many others know nothing about these engines and have never had any actual experience of owning one, but have read too many threads/post about people having serious trouble coming from an initial innocent enough sounding issue on SEAT, VW and Skoda motoring forums. Investigating this quickly might just prove me wrong or allow you to get this engine sorted out cheaper.

 

[Glove]

Could well be another dud coil pack or they could have damaged the wires pulling the old one out. Try a new Bosch pack from eurocarparts in there and see how it goes. A coil pack pulling tool is essential too.

 

[everson38]

Yeah I think your options are 1) Do some repairs on your car yourself that will save on labour and carry out the jobs that any YouTube channel or mechanic will tell to replace / fix when you car judders / misfires. Or 2) Take it to seat and have them try pin point it. Repair it or at least give you info

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[PraiseTheSun]

So I took the car to SEAT.
They tell there are no error codes, which is odd because I 100% saw the check engine light come on.

They did some diagnostics and believe there is low pressure in cylinder 3.

It is a 2010 car so it's possible the piston rings need replacing?

They are going to do more tests today/tomorrow.

I also recently had the car remapped and am now worrying it could be the culprit or at least involved somehow...
I wonder how easy it is to unmap, if SEAT can do that themselves?

As much fun as this car has been I fear it's time to get something new.

 

[Legojon]

Seat can flash a factory file back over the map. I had it done on my previous FR+.

 

[PraiseTheSun]

I just spoke with them, they were a little "upset" I didn't mention it had been remapped. To be honest it completely slipped my mind.

They are going to re-flash the ECU and do the tests again.

Welp, that's £250 for the remap down the drain.

 

[everson38]

I just spoke with them, they were a little "upset" I didn't mention it had been remapped. To be honest it completely slipped my mind.

They are going to re-flash the ECU and do the tests again.

Welp, that's £250 for the remap down the drain.

Lol. How did they convey "upset" to you. They weren't rude were they. Yeah annoying about the remap. I am a big believer of leave electrical things alone. But hey this may provide better / good news. So fingers crosse ld in what it could be.

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[Legojon]

Who was it mapped with? Have you spoken with them? Also, I had mine custom mapped before. Lost it due to Seat flashing it (at my request). The guy said if I'd brought it back to him first so he could note down my settings, he could have put the map back on for cheaps as it wouldn't need dyno/custom setup again.

Weird the misfire codes were for Cyl2 and they said Cyl3 pressure is low.

 

[PraiseTheSun]

Well the error code was originally for cyl2, which was cleared by changing the spark plugs/coil pack.
Then a day later this juddering issue reared its head.

To be honest I don't really mind if they wipe the remap, I am going to sell it as soon as they fix it.

Very interested in Inifiniti and Lexus at the moment - those cars seem bullet proof.

 

[PraiseTheSun]

Lol. How did they convey "upset" to you. They weren't rude were they. Yeah annoying about the remap. I am a big believer of leave electrical things alone. But hey this may provide better / good news. So fingers crosse ld in what it could be.

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I spoke directly with the mechanic. He was very polite but I could tell by his half laughing half astonished voice he was upset, like he’s wasted time or the solution is super simple now.

I’ll hear back in a few days and will update. Cheers.

 

[RUM4MO]

I'd think that it is more likely the piston(s) that are the trouble, seems they usually are and the design was changed, so if a piston needs replacing they will always replace all 4. I suppose that it all depends what in the way of "sorting" has already been done to this engine since it left the VW Group engine plant. SEAT UK could tell you its official history.

 

[PraiseTheSun]

So SEAT just called me. They undid the remap and done the tests again and it’s showing all fine. So the problem was the remap.

Who knows if the company doing the remap ****** it up or this delicate engine just can’t handle being tuned any other way. Either way they says it’s fixed, he went for a drive and gave it loads of welly with no issues.

At least I can sell it now

 

[anz]

my seat leon tfsi fr 2007
while I drive on low revs rpm drop to 800 from 1500 at 20 mph and shake some times violently same when 70 mph from 2500 to 2000.
this happens sometimes but every day when I drive.
I have changed spark plugs, coil pack,pcv valve, high pressure fuel pump, cam followed, breather pipe, maf cleaned.but still no luck.
please help me
no engine light
nothing on the diagnostic machine

 

[everson38]

my seat leon tfsi fr 2007
while I drive on low revs rpm drop to 800 from 1500 at 20 mph and shake some times violently same when 70 mph from 2500 to 2000.
this happens sometimes but every day when I drive.
I have changed spark plugs, coil pack,pcv valve, high pressure fuel pump, cam followed, breather pipe, maf cleaned.but still no luck.
please help me
no engine light
nothing on the diagnostic machine

Following from the above have you had a remap done?

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[anz]

the mechanic solved the problem it was the crank position sensor