Golf 118 TSI Engine Failures and Service Campaign 24S4

[skyva]

Doesnt sound good. I know the mods are keen for us not to be canning the dealer but I would not behappy with the result. You are very patient to accept that the engine fault was returned not fixed and the car not properly put together aftwards. I would have not have been sympathetic, however you do need to keep the dealer onside to get the car fixed. Is there any other dealer you can take it to? Does anyone here know of great service center? I am not criticizing the dealer, as no doubt they are trying hard. However I would not accept that after working on your car they could not identify the fault and gave it back to you with problems, and when you call they still have no idea. It may be that another dealer has a more experienced mechanic who can help. After all, not every dealer has the same mechanics, and even doctors send you to specialists.
Unburnt fuel smell is a problem. I believe there are sensors in the exhaust that detect unburnt fuel to adjust the mixture from lean to rich. Maybe one of the sensors might be misreading, but it could be anything. Pinging is also bad. With all the tech involved in these engines, i would have a look at the sensors as the pinging could be pre-ignition, causing incomplete combustion resulting in unburnt fuel and a lack of power. These issues can be hard to track unless you start replacing sensors.

Can they connect up a data logger to the ecu and go for a drive? That would be my request. If you can get the car to repeat the fault while the data logger is attached then they have something to work with. I am guessing that they didn't see the fault themselves when they gave you the car back. I believe that only some dealerships have these data loggers, so they may need to get one in and send you home with it for a days drive or so. It can't hurt to ask, particularly if they are starting to say that they are stumped.
Is there a chance it could be a batch of dodgy fuel? We had some in Melbourne a few weeks back. I would try to fill up with the best fuel you can get, not from your usual source, ideally the best (ie most expensive) BP fuel you can find, I forget the brand name. If the car runs better after that then that may help diagnose the problem, otherwise you can only leave it to the dealer. Less pinging on high octane fuel would suggest pre-ignition.

At least Gerhard doesn't think there will be a loss of value in the car. You can always sell it to him if things don't work out to your satisfaction

[cktsi]

Thanks for the tips Skyva. When I first had the supercharger chirp diagnosed, the Barloworld service manager said that the Mascot workshop had a "gun" technician and to take the car there to verify the problem.

Unfortunately in that instance, it was confirmed they couldn't immediately fix the problem.

But yes, I do have another workshop I can take the car to. Even though FD VW don't like me talking to the technicians, slightly different culture at Mascot where I had direct access to the head technician.

Agree that it's not an acceptable result because it's a breakdown waiting to happen. It may be due to the unburnt fuel still clogging up the exhaust system, but I've got that petrol smell when the engine stops.

Your suggestions are good ones and I think Mascot can accomodate this request.

I think I still need to take it to Five Dock on Monday morning only to put the rear bench back properly. If I can replicate the problem, I'll leave the car there. If not, I'm driving to Mascot.

In the meantime, I will shift the gears myself rather than leave it to the DSG. I do think the DSG places too much strain on the engine by stubbornly keeping higher gears, where in a manual I would be gearing down. In my old Mark 5 2.0FSI I geared up around 2,100 rpm in each gear. From memory the DSG goes

1,900
1,800
1,650
1,650
1,600
1,600

I think 1,650 in 3rd is way too low ! I'd still be waiting for around 2,000 rpm. The higher gears could also do with waiting for another 200rpm before kicking higher.

[logger]

...may be due to the unburnt fuel still clogging up the exhaust system...

I very much doubt that. Run you car for a couple of minutes then grab your exhaust pipe. Temps in there are much too high for unburnt fuel to be pooling and in any case if it was, the smell would predominantly be at the tailpipe and not in the car.
You said they

..didn't put the rear bench back properly & there's some sound deadening cloth poking out...

AND

I've got that petrol smell when the engine stops...

Have you considered why they removed the rear bench? Likely reason to remove back seat could only be to access the fuel tank. My bet it that this is the source of you fuel smell and not the engine. Air the car out with windows open for a few hours. Might take a few days to go completely though. My Toyota Kluger had a fuel pump change about 6 months back which required rear seat removal for access. Took nearly a week for the smell to go.

So to take stock - Assuming you had no fuel smell, because it may just go in a day or two - What problem are you actually left with that makes you think engine failure is imminent?

[cktsi]

To clarify, the fuel smell is outside the car, not inside. However, it does sound like they've done something with the fuel pump.

When I say "breakdown waiting to happen", I refer to the fact that the symptom that lead to the breakdown is still there i.e. tick tick tick noise from the engine followed by a plume of unburnt fuel from the exhaust.

If the symptom is still there, I think the problem is still there... ergo: the car will probably breakdown again because the root cause is still present.

The service centre guy does want to diagnose the problem, but he's saying only if there's something to diagnose. Skyva's suggestion to use a logger is a good one - though they will probably want to keep the car than let me run off with their data logger :p

[logger]

Fair enough. I suppose if there is any consolation, the intermittent nature suggest there is not something mechanical broken in the guts of the engine which would show as a hard fault. I imagine they were investigating the fuel system looking for contamination & or blockages.

[skyva]

If they cannot diagnose the problem and you can replicate it, then insist on having a long term data logger put into the car. By long term I mean 72 hours or so. I have only read about it, but from what I hear, not every dealer has one, so they need to book it in for you to take away with you. It may mean you have to record the exact time you experience the problem so they can match the time in the data logger. A problem with data loggers is that they record huge amounts of data, and data that is normal, for example, going up a hill in low revs, may not be normal for freeway driving.
It may not be relevant, but in my (very) old car we made sure we gave it a caning every now and again, as there could be a build up of carbon in the cylinders. When carbon build up is present, bits of it heat up and cause pre-ignition, resulting in poor combustion. There are so many computerised parts on these new engines that it is not possible to say if this is the case, but if you do a lot of driving where the engine lugs (low rpm, high load), then my thoughts are that it might benefit from a high rpm blast.
Also, it may depend on how you drive. Modern cars have an adaptive throttle control, where it monitors past driving and adapt shift points. This means that if you regularly thrash your car, the computer recognises this and sets the throttle to be sensitive, with higher change points. If you regularly drive conservatively, then the throttle control and transmission may choose to change up earlier than you like. This may cause the change up issue you mentioned and some carbon build up. You used to be able to solve the problem by disconnecting the battery and turning on the ignition key and holding it on for several seconds. Nothing would happen of course, but the charge in the electrical system would deplete, wiping the adaptive memory. I am not sure how VW's work in terms of adaptive control, it may take the dealer to reset it.
If you are not happy with the change points your car chooses, may I suggest asking the dealer whether there is a way to reset any adaptive throttle control memory so it starts from scratch and you can drive it to encourage higher rpm change points.
It would be great if someone familiar with these systems could add some advice as I am really only guessing on the specific system used by VW.
It sounds like everyone is trying to help so that is one positive step.

Good luck.

[cktsi]

Would carbon build up in such a new car & in less than 3 months? Sounds a bit soon to me.

I was also wondering if any other 118TSI drivers experience the same issue. They may not be reading this thread, so may be worthwhile starting a new one (not that I like clogging up forums with bad news or anything).

Yesterday the car was fine (really nice having a car with a sunroof in really good weather).

Today there was the same ticking & unburnt fuel belch. It seems to happen when I'm accelerating uphill (i.e. under load) in 5th or 6th gear and the engine is revving from 1,600rpm.

I'm also certain the engine is now a little rough under heavy acceleration between 2,000 - 3,000 rpm (and wide open throttle) where before it was smooth.

Other than those hiccups, the car was behaving itself... and yeah... really good to have a car with aircon & sunroof in Sydney this weekend Also nice to use the remote to open the windows & let the hot air expel before I enter the car.

Oh... I also did try to use the turbo more today to 'unclog' any carbon build up by building revs slowly to 3,000rpm... then when the traffic in front clears I let loose. Boy what a feeling when the turbo flies !

[cktsi]

Looks like there's a Jetta with the same 118 TSI 1.4 engine with the same issue in the Mark V forum. !

[pologti18t]

Can't you put the DSG in Sports mode? That should raise the gear shift points.

I noticed this in your remarks

Do you happen to notice a plume of unburnt fuel out the back by any chance when this happens?

HOw do you see an plume of unburnt fuel? Is it dark grey smoke?

[cktsi]

Can't you put the DSG in Sports mode? That should raise the gear shift points.

I noticed this in your remarks


HOw do you see an plume of unburnt fuel? Is it dark grey smoke?

The problem with sports mode is the gear changes are too aggressive for suburban driving. Fine for open road twisties.

It wont shift until at least 5,000rpm is reached. If i accelerate moderately it will red line. I dont really want to constantly thrash the car.

The unburnt fuel is not smoke. Just a brownish cloud of fuel. Same thing you see in any car under heavy acceleration.