GolfGTIforum.co.uk
Model specific boards => Golf mk6 => Topic started by: Norwichdaz on 01 May 2026, 15:20
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Hi guys,
Its the 2nd time happend in 2 months now, after a sh!tty 45 min city drive in traffic etc starts to get an eggy smell inside the cab.
The engine doesn't over heat or run any differently, but engine light came on (came on 2mths ago and went in a few days)
But say I turn it off then on it struggles slightly.
"Google" says if struggles to turn on once hot could possibly be high pressure fuel pump?
I mean anyone else with that kinda smell would say the cat converter.
Seen somewhere a possible bad o2 sensor too?
Going to obvs get it scanned asap.
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As you say Eggy smell is often a poorly regulated catalyst converter or a running issue causing the cat to smell. A scan will give you more indications.
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Scanned today same things that have come up for a while for some reason...
The mechanic said he thought could be injectors possibly flooding the cylinders and damaging the cat? Mentioned walnut blasting..
Didnt .mention a thing about a faulty o2 sensor etc ..hmmm
As I say runs no different, doesn't seem sluggish, just that smell in heavy traffic and the odd engine light .
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(https://i.postimg.cc/tJgZbTH5/Screenshot-20260518-192421-Outlook.jpg) (https://postimg.cc/sQtD93xQ)
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The same thing happened to my GTI last year, but in my case, the performance was hit too.
After cleaning the injectors and replacing the plugs, the mechanic replaced the pressure control valve (I think that’s what it’s called) and all was well.
I was getting the same P0172 code that you’ve got.
Hope you get it sorted.
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Ah ok mate cheers,
Yeh around 6 mths ago have had all new plugs,coils and pcv tbf.
I know bit of a chore with the injectors if wanted to properly check them.
As I say just if sat around in city traffic, bit random.
Im guessing a bottle of cataclean is jist "gimicky" ? Or worth a shot or running one thru?
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To be honest, I’d give it a shot. In fact, I may still do that.
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Okey doke, the mechanic also said as done 160k , to walnut blasting, but not much change from £450, not sure how that would stop the smell in heavy traffic etc tho? Lol
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I’m no mechanic, but walnut blasting does seem to be clutching at straws. Do you have another mechanic you can try?
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Walnut blasting probably isn’t aimed at the smell itself mate it’s more about fixing one of the likely causes behind it.
On these direct injection GTIs, the intake valves get heavily carboned up over time because fuel never washes over them. At 160k, chances are the valves are pretty coked up unless it’s been done before.
That buildup can cause:
- rough hot starts
- poor airflow
- uneven combustion/misfires
- rich running (your P0172 code)
- excess unburnt fuel going into the cat
That last bit is what often causes the rotten egg/sulphur smell in traffic because the cat gets overloaded and starts producing hydrogen sulphide.
So the mechanic’s probably thinking:
carbon buildup → engine running rich/poor combustion → cat overheating/smelling.
Walnut blasting won’t magically “fix” a dead cat or faulty injector if one’s already gone bad, but on a high mileage it’s definitely not clutching at straws either it’s proper maintenance and could improve the hot start issue too.
Personally though, before spending £450, I’d still want:
- fuel trims checked
- injector balance/leak test
- HPFP pressure checked
- live O2 sensor readings checked
because a leaking injector or failing pressure control valve could also explain the rich code and egg smell.
Finally, if it was me, I would only use a Garage that really knows what they are doing and have the injectors ultrasonic cleaned if they are good or replaced if they are not as well as the injector seats checked for leaks.
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Thx nino as always!!! Great knowledge 👏 👏
Yeh I know might help clean it out etc, as I say runs fine,performance wouldnt say notice much difference..
But obviously in my head if start sitting around in traffic your just waiting for the light to.come on etc..
I must admit its a 8mile trip to work and I know wouldnt just get bad in 8mths or so that iv had it but honestly not thrashed it much at all pretty standard driving since purchased tbf haha...
Also nearly time for gearbox service and a general service... wasnt sure even to keep it still or not as dont have endless cash to keep throwing at it haha...
The other stuff u said to get checked out first tho is definitely an idea 👌👌👌👌👏
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Aye, I get it. cars will always cost money. my Edition 35 is only on 84k but I recently had to replace both my rear calipers due to them binding :(
then the very next day my Windscreen randomly cracked :grin:
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Ah whaaaat ?! Haha
I still think my back left is binding when u release handbrake and pull away u get a clunk then a grind for first few brakes...
But had that checked as caliper etc seemed fine,u less was handbrake etc...
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I did have a cheeky go at some rust on the front arch, rubbed down,primer, different wet and dry, paint, etc and tbh it came out pretty good.
(https://i.postimg.cc/NfhWtnH5/20260430-110844.jpg) (https://postimg.cc/QVb6k0S3)
(https://i.postimg.cc/BQWd3zKT/20260430-182948.jpg) (https://postimg.cc/vDzPL3XT)
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These cars are always going to be a labour of love, they’ll cost us money, we’ll be frustrated, but ultimately, still love them 🤣
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Ah whaaaat ?! Haha
I still think my back left is binding when u release handbrake and pull away u get a clunk then a grind for first few brakes...
But had that checked as caliper etc seemed fine,u less was handbrake etc...
This was mine. (Handbrake was off here)
https://www.youtube.com/shorts/mAjov8hLC4g
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I did have a cheeky go at some rust on the front arch, rubbed down,primer, different wet and dry, paint, etc and tbh it came out pretty good.
(https://i.postimg.cc/NfhWtnH5/20260430-110844.jpg) (https://postimg.cc/QVb6k0S3)
(https://i.postimg.cc/BQWd3zKT/20260430-182948.jpg) (https://postimg.cc/vDzPL3XT)
Increadable work there :cool:
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Haha thx , in person slightly duller white but a lot better than rust lol
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Ah whaaaat ?! Haha
I still think my back left is binding when u release handbrake and pull away u get a clunk then a grind for first few brakes...
But had that checked as caliper etc seemed fine,u less was handbrake etc...
This was mine. (Handbrake was off here)
https://www.youtube.com/shorts/mAjov8hLC4g
Incase you missed this post :)
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Haha niceone ta, yeh not sure... in the hest today after driving for newrly an hour tur ed off for 5 mins went to start and was a hard start had to put accelerator down... otherwise all good lol
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I’ve had the exact same issue today…Started fine this morning, drove around for a while and parked up, came back to the car a while later, took several attempts and a bit of accelerator for it to start. After that, all is well. 🤯
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Hmmm lol
(https://i.postimg.cc/DZ0VD3gN/Screenshot-20260523-194458-Google.jpg) (https://postimg.cc/4KDF7Mjv)
(https://i.postimg.cc/d13MXcBp/Screenshot-20260523-194836-Google.jpg) (https://postimg.cc/TyzHLSBJ)
(https://i.postimg.cc/G2t0NnQW/Screenshot-20260523-194917-Google.jpg) (https://postimg.cc/jWpkw9Bc)
(https://i.postimg.cc/PxJGcn4B/Screenshot-20260523-194941-Google.jpg) (https://postimg.cc/QB2n9Pvb)
(https://i.postimg.cc/ydxq5Cjq/Screenshot-20260523-195051-Google.jpg) (https://postimg.cc/06THM3hZ)
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At this point, I would find a garage that can;
- Perofrm a walnut blast.
- Ultrasonic bath & Clean all the injectors.
- Check Injector seats for leaks.
- Replace anything that needs replacing.
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Yeh will try get pressure tested etc dont quite have loads of money to do a walnut blasting at this minute tbf..
So tricky haha...
Just saw online the cam follower seems easy enough to do but cant see that doing the hard hot start/smell now and again... this hot weather isn't helping tbf probably haha... oil and water temps always fine.
.
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Yeh will try get pressure tested etc dont quite have loads of money to do a walnut blasting at this minute tbf..
So tricky haha...
Just saw online the cam follower seems easy enough to do but cant see that doing the hard hot start/smell now and again... this hot weather isn't helping tbf probably haha... oil and water temps always fine.
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Yeah I totally get that mate, I think all of us are feeling the sqeeze atm.
I did the cam follower myself when I bought my Eddy, its easy to do, just take your time. I followed this guide... (Watch it from 10:05)
https://youtu.be/9LNfqqNWmKY?si=Ep23SfxDrxwZ14OD&t=606
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Ok mate great cheers ... 😃👌