2.0 TDI (DSG) CKFC engine.

I'm hoping someone can shed some light on a starting issue I've been experiencing.

It's happened maybe five or six times in the last six weeks, although I don't drive it every day.

It only seems to happen when it's warm, not when starting from cold.

This morning, I drove about 10 miles into town, parked for about 90 minutes, and when I came to restart, it took three attempts. It turns over and fires, but then stops instantly.

I then drove a short distance to another location, where I stopped for about 20 minutes. It then started fine, but when leaving the car park, the traffic lights on the exit turned to red and stop/start kicked in. When the lights changed, I took my foot off the brake, the engine fired then instantly stopped. Put my foot back on the brake, released it and the engine started.

That's the first time I've noticed it with stop/start, but I quite often disable it, so it's not really representative of what it does.

On the other occasions when it has failed to warm-start (on the key), it normally starts on the third attempt.

I've done an OBDeleven scan, but that hasn't shown anything.

I was hoping someone has seen this before and could possibly give me an idea of where to start investigating.

Thanks.

If you have a multimeter check your battery a lot of starting issues are related to that

That is something I had considered, but I wouldn’t have expected stop/start to be operating if the battery was struggling.

Also, it doesn’t struggle to turn over, it’s the fact that it fires then cuts out that is puzzling.

I think I will try another battery anyway, as this is the original and ten years old.

When I checked it yesterday, it was only showing 12.1v, and when cranking, it appeared to drop to 8v, although it only cranked for about one second before starting.

15 minutes ago, daveo138 said:

When I checked it yesterday, it was only showing 12.1v, and when cranking, it appeared to drop to 8v, although it only cranked for about one second before starting.

Marginal - and if the battery is 10 years old and original, then yes, it should be replaced. You can confirm this yourself by doing a CCA test on the battery. Anything less than 60-70% capacity IMHO means a new battery is required.

One of the issues i had with a weak battery was the car would just spin over automatically, but not fire, second attempt fine, new battery all good, but i had lost stop start a while back.

What does obd eleven say about battery health?

I had a 2.0 TDI (CUNA) behaving similarly, somewhat often while starting warm engine, it cud start easily but shut down immediately, like the starting process had been cut off too early. Few times it did it also with cold engine. Reason was camshaft position sensor. Easy DIY job. Might be that, can not say for sure ofc.

Caught it with VCDS, intermittent implausible signal from the sensor was stored in the engine fault codes memory, even tho engine module was not highlighted as red in auto scan gateway installation list, how it usually is if there is fault codes stored.

Edit. CUNA has variable valve time system and I believe that is why the sensor cud cause such problem. Perhaps check first if CKFC has it too. And it might also be fault in the variable valve system, but I wud expect fault codes from that.

Edited 18 May, 20251 yr by Skodaudi

22 hours ago, Skodaudi said:

CUNA has variable valve time system and I believe that is why the sensor cud cause such problem. Perhaps check first if CKFC has it too. And it might also be fault in the variable valve system, but I wud expect fault codes from that.

If there is ever a reason why you need to regularly change your oil, the above is a good reason why.

This has been an issue with the 1.9 over the years and pops up now and then with the 2.0. When my 1.9 had it I tried all sorts of "repairs". New battery, refurbed alternator, cleaned up earth straps, etc, etc. Some helped, others didn't. The only thing that finally fixed it was a remap. It was totally accidental and I had learned to live with the issue. My approach was to turn the key for one engine rotation, back off and go again. It worked every time. When I got the remap, I did the same but noticed it responded differently on the first rotation. After that it started on the button every time.

The actual issue was to do with the crank speed sensor needing a certain minimum value before the system would start pumping fuel. The starter was only ever able to turn at the required speed when new/clean. It soon lost the ability to crank fast enough. I don't think the 2.0 has quite the same cause but the symptoms are very similar. I am yet to hear of a remap solving it though as very few are willing to try on what they think is a duff engine.

I'm leaning towards more a crank position sensor, or quite likely immobilizer fault. Most of the time immobilizer presents as a start and instantly stop the engine symptom

On 18/05/2025 at 10:25, Skodaudi said:

I had a 2.0 TDI (CUNA) behaving similarly, somewhat often while starting warm engine, it cud start easily but shut down immediately, like the starting process had been cut off too early. Few times it did it also with cold engine. Reason was camshaft position sensor. Easy DIY job. Might be that, can not say for sure ofc.

Caught it with VCDS, intermittent implausible signal from the sensor was stored in the engine fault codes memory, even tho engine module was not highlighted as red in auto scan gateway installation list, how it usually is if there is fault codes stored.

Edit. CUNA has variable valve time system and I believe that is why the sensor cud cause such problem. Perhaps check first if CKFC has it too. And it might also be fault in the variable valve system, but I wud expect fault codes from that.

Don't suppose you've got a photo of where the cam sensor is? Got a cutting out/intermittent juddering issue with mine with some wonky sensor readings so want to change it. Just not sure where it is.

1 hour ago, dmcmylor said:

Don't suppose you've got a photo of where the cam sensor is? Got a cutting out/intermittent juddering issue with mine with some wonky sensor readings so want to change it. Just not sure where it is.

This is from the Golf Haynes manual.

The camshaft position sensor is located at the front of the cylinder head.

Remove the fuel line bracket bolts and move the fuel line to the side.

Disconnect the sensor wiring plug connector and remove the sensor retaining bolt. Remove the sensor.

25 minutes ago, daveo138 said:

This is from the Golf Haynes manual.

The camshaft position sensor is located at the front of the cylinder head.

Remove the fuel line bracket bolts and move the fuel line to the side.

Disconnect the sensor wiring plug connector and remove the sensor retaining bolt. Remove the sensor.

Brilliant, thank you. I'll have a look after work :-)

Quick update:

I fitted a new battery nearly three weeks ago and haven't experienced any more issues, so I'm hoping that's all it was.