1.6 CAYC rough idle

[lightbreeze]

Hello!
I'm new to this forum and apologise if I missed similar topic in search.
I've got Golf Mk6 1.6 TDI for at least 2.5 years or so...with the problem - wobbly idling. It started about a year ago, I did not notice the problem before. The engine always starts normally but while it's warming up (esp. when the t is below +3°C) and revs decrease from ~1100 to standard 780-800 it snorts and wobbles a bit.
Actually I guess it's all about faulty injectors... There are 03L130277B ones, never been replaced. The mileage is 157k on dashboard, but the actual number is unknown cuz it's been cut down :-\ I took the injectors out and checked them on Rabotti Unitec bench which showed that they are really been worn out. VCDS also showed that injectors work pretty rough. I can attach screenshots later if needed. Btw, fuel consumption is increased a bit in a city cycle.
Occasionally the engine works absolutely normally, but when it's idling and I slightly put accelerator pedal to ~900 revs and immediately release it the engine begins to wobble and sound like a tractor again. And also when it's alright I push the clutch pedal and slowly release it (on neutral gear) the same thing happens. Tr-tr-tr-tr...and so on. It's enough to push on the throttle to make the engine work normally. But it can shake on idle constantly until I restart the engine. ***Here's a video (https://www.youtube.com/watch?v=_steUu8aASM)*** for an example (with a Polo, but it doesn't matter if the engine is the same).

But sometimes the engine runs smoothly as if nothing had happened. It seems that he lives his own life :-| So what's the actual problem?
p.s. Seems there's no EGR and no DPF.

Sorry for my bad English, haven't written in it for quite a long time.
Regards, Nick

[lightbreeze]

Ok, been to dealership:
35512
Seems to be good? The engine's been working absolutely properly at that moment. But the 2nd injector values sometimes fluctuate 0.6...9(!) mg/stroke!!! Thanks to the serviceman who've noticed that, I couldn't almost see this without him.
So after diagnostics he told me all 4 injectors should be changed...Can't believe that's the decision to my problem.

The next day I've noticed this:


https://www.youtube.com/watch?v=iSjyKR60dUw

So what the actual problem I'm worrying about? Now I guess it's not the injectors :-/

[lightbreeze]

And when I start the engine and it's been reducing revs from 1100 to 800 while warming up it shakes bit as well but then it works fine till it's got normal operating temperature. Maybe the problem is in the sensors?

[Crasher]

Has it had the stupid emissions update?

[lightbreeze]

I guess no cuz the issue began for no reason. Never had any updates so far since I'm the owner

[Rob69]

Is it still the original dual mass flywheel?

[lightbreeze]

No mate, it's been replaced to single mass Valeo (model no. 835035) but I should say the actual problem has already been before.
And the clutch and flywheel replacement wasn't in vain actually, the old one Sachs has been pretty battered
But I still don't know was this decision correct or not - there was no time to wait Sachs for delivery...so anyway the clutch's been working good
---
Throttle valve is cleaned, engine mounts have been replaced, timing belt and V-belt replaced, etc
There's lots of videos on YT on this issue and in most cases, judging by comments, the problem is in the injectors. But after scrolling down some forums I've noticed that the problem is software related rather than mechanics

[Crasher]

The CAYC engine was initially built with a solid flywheel but later one was added and a TPI notice issued about converting cars with single mass to dual mass but the injectors are also a major issue and stupidly expensive, they cost twice as much and take longer to replace than an Audi RS6 V10 which is ridiculous.

[lightbreeze]

Ok, maybe it's really the time to replace them. Pity the price is incredible. But I still guess the essence of the problem is different, not the injectors

[AlexTheGrumpyOn]

Hello mate in case of replacing injectors, which is aperently quiet common on 1.6tdi i have got a coding process video that might be helpful. As they need coding to run properly.

Vw Golf 1.6 TDI 2011 injector replacement and coding. How to do it? - YouTube (https://youtu.be/ZHi8nsfhKlo)

Sorry Ill introduce myself as well while im here :)
MY name is Alex and I’m a Vehicle Pro Technician from Kent.
I currently got Audi Q3 2.0 TDI Sline, Skoda Fabia VSR 1.9TDI and Toyota Supra MK4.
Had over 12 VAG group cars in last 4 Years! Most of them TDI.
In 2018 I’ve created a Youtube Channel that got over 170 videos. That include loads and mainly VAG car Problem solutions. Pretty much everything we got on the road.
Aim of my channel is to help everyone with any car issues including buying them as well. Have a quick look at my channel and Subscribe if you think it that it might be helpful to you one day!
Share if you can, as this service is free and my aim is to dedicate myself 100% in to this. Success for me will be opening my little workshop where I can give honest help and advice and also support this channel to provide as many videos and help as I can!
I will really appreciate any support like subscribe, like or share of my channel!

I can provide help in 5 Different languages.
MY Youtube Channel is AlexTheGrumpyOne
Facebook profile is also AlexTheGrumpyOne!

www.youtube.com/c/alexthegrumpyone

[jake310890]

1.6 tdi 2009
Rough idle wen cold Stalls, misfire
seems to have a little miss fire wen warm,
Limp mode
glow plug light
Had air mass sensor last week as I broke down would tick over but not generate any power, code was a
mass or volume air flow circuit range / performance, Reset and replaced the valve no change,
Back to the above symptoms
New codes today

P10100 mass or volume air flow circuit range / performance,
P029900 turbo / supercharger under boost

I fort the rough idle the stalling it was injectors,
But with above codes I’m a bit lost,

Any help is appreciated,

[Crasher]

You need to start your own thread AND most importantly have a proper VCDS code read carried out and post the results using the hashtag code code function in advanced reply. Where was the new Air Mass Meter bought from and do you know the part number?

[jake310890]

New one is a NTK, form TPS was not cheep, the original part number 03L90646- the car currently has no faults it’s just waiting till it throws a code to get a Vag report,

[ingeborgsjon]

1.6 tdi 2009
Rough idle wen cold Stalls, misfire
seems to have a little miss fire wen warm,
Limp mode
glow plug light
Had air mass sensor last week as I broke down would tick over but not generate any power, code was a
mass or volume air flow circuit range / performance, Reset and replaced the valve no change,
Back to the above symptoms
New codes today

P10100 mass or volume air flow circuit range / performance,
P029900 turbo / supercharger under boost

I fort the rough idle the stalling it was injectors,
But with above codes I’m a bit lost,

Any help is appreciated,
I had similar problems recently and the air mass meter code. It turned out to be a failing EGR cooler. And it eventually failed completely with the EGR valve flap falling of it's axle and the car didn't even start so it had to be towed.

So I had the EGR replaced. Not very cheap because it's 4.5 hours of work for a professional. And then about £300 in parts (EGR cooler, gaskets, stretch bolts, etc). Now every symptom is gone except for the rough idle. I think that's because of one or two bad injectors.