Scirocco r misfire

Author
Discussion

Grassymango

Original Poster:

2 posts

30 months

Monday 16th May 2022
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Hello my brother has a scirocco type r we live in guernsey so big car small island. Every 2k miles or so he goes downhill and car starts juddering and gets epc light flashing. Then misfire cylinder 1. Last time was cylinder 3 and before that 2. The car has been to specialist they changed the pcv valve it helped for about 500 miles. He also has to drive it in sport mode we are worried about carbon buildup. I have had the intake manifold off cleaned up replaced gaskets. Also checked plugs they are black?? I dont know what else to do he has been to 3 garages and they keep fobbing him off.
Thanks

ninjag

1,874 posts

126 months

Monday 16th May 2022
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Grassymango said:
Hello my brother has a scirocco type r we live in guernsey so big car small island. Every 2k miles or so he goes downhill and car starts juddering and gets epc light flashing. Then misfire cylinder 1. Last time was cylinder 3 and before that 2. The car has been to specialist they changed the pcv valve it helped for about 500 miles. He also has to drive it in sport mode we are worried about carbon buildup. I have had the intake manifold off cleaned up replaced gaskets. Also checked plugs they are black?? I dont know what else to do he has been to 3 garages and they keep fobbing him off.
Thanks
If the spark plugs are black then that could well be carbon fouling. Were the spark plug gaps checked?

Grassymango

Original Poster:

2 posts

30 months

Monday 16th May 2022
quotequote all
No just replaced. I'm buying a gap checker! Ok for info if plugs are new should you gap them? Also what might you suggest itf that fails? Im getting new plugs in meantime. I like your wisdom thanks Robbie

ninjag

1,874 posts

126 months

Tuesday 17th May 2022
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Grassymango said:
No just replaced. I'm buying a gap checker! Ok for info if plugs are new should you gap them? Also what might you suggest itf that fails? Im getting new plugs in meantime. I like your wisdom thanks Robbie
They normally come pre-gapped, however, last year I put new plugs in my car which were meant to be pre-gapped and I started to notice a hesitation when accelerating moderately up to 2,000rpm. Very mild acceleration or foot to the floor was fine though. I checked my plugs on Sunday night just there and the gaps were all about 0.5-0.6mm instead of 0.7-0.8mm. I re-gapped them and it runs much better now.

I guess it's a simple check so worth doing as part of the process of elimination?


Edited by ninjag on Monday 23 May 15:09

rottenegg

805 posts

70 months

Friday 20th May 2022
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You haven't stated the model year or mileage, or whether the issue occurs hot or cold, or both, whether it's standard or modified but if it's short journey carbon related, the misfiring could be down to clogged up valves/ports upsetting the mixture in stratified injection mode. Very common on TFSI engines that rarely get hot.

If not that, it will likely be one or more injectors.

Farmerpalmer

275 posts

171 months

Saturday 21st May 2022
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Having lived in Guernsey many years ago, i am aware of the speed limits and lack of opportunities to go for a blast. So probably carbon build up everywhere . Suggest take the car off the island and go for a motorway blast

markbmw

120 posts

191 months

Monday 23rd May 2022
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Im fairly new to VW, however a common mantra for the TSi engines is thus; just add fuel and coils.

rottenegg

805 posts

70 months

Monday 23rd May 2022
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markbmw said:
Im fairly new to VW, however a common mantra for the TSi engines is thus; just add fuel and coils.
And oil.



markbmw

120 posts

191 months

Saturday 26th November 2022
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Interesting. In 30k miles, my 2.0 tsi hasn't used a drop of oil.

The 1.4 tsi in my old Golf GT (turbo&supercharged) drank 0.5ltr monthly (150-200miles)
I used to wonder if the service oil changes were a waste !

Dr G

15,403 posts

249 months

Saturday 26th November 2022
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My 2016 is about to click 95k and uses maybe 1-1.5 litres in a year (10k miles). Oil consumption really isn't an issue with these. The older 113 engine did use a bit but wasn't generally excessive without a load of miles or PCV fault.

Early 888 had known piston ring issues that tend to be fine after the revised/pistons rings fitted.

What's the Scirocco like at idle, OP? Little rough/fluttery by any chance?

Tony1963

5,331 posts

169 months

Saturday 26th November 2022
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I think most here would agree that at the very least the poor car needs a bloody good drive. Here on the mainland I’d be going for a 150+ mile drive with a good variety of roads and revs. Only after that would I start trying to diagnose an intermittent fault. Give the engine half a chance, at least!

Guernsey must be an ideal location for an EV?