Another unsimple post from myself about my Octy vRS 07 tdi ( PD170 )

My car sometimes cuts out when driving slow, for eg when slowing down for a roundabout. I won't even feel it, the engine has just turned it self off.

No lights on the dash other than the red battery light. I fire the car back up and it starts fine and drives normal again.

It has been suggested to me to bleed the clutch as it could be causing drag but the car has now done the same ' engine off/dying ' at speed, say 60mph. The revs and speed just start reducing and the engine is off. I can't accelerate but I can still brake and steer so now I don't think it is just clutch dragging and actually something more sincester.

I'm not sure if this is related but twice now when I've turned my ignition on the temp gauge has gone straight to 120c and sat there with the red coolant light flashing - I start the car and the temp gauge goes back to normal.

First occasion - it was a hot day and I had only left the car an hour before driving again and the temp gauge read 90c

Second - it was a cold day and the car hadn't been driven for a good 8hrs and temp guage read 0c

Thanks for any ideas!

Bump

Are your fans running? can you get a VCDS read to see if there is anything listed.

 

Water pump changed with cambelt change? coolant levels okay?

My fans work yes. VCDS shows no faults.

Yes cambelt and waterpump ( inc tensioners, pulleys Etc ) changed at 114,000. Car now on 135,000.

Coolant is on max mark when cold and higher when warm.

What does VCDS say the temperature is? If it says 120C etc then replace the coolant temperature sensor with a genuine spare. Cheap to find out!

I have had the same thing when slowing down at roundabouts etc and a couple of times at faster speeds, had been told could be interrupting a dpf regen but have had it happen twice in 2 minutes so would rule that out I think. Can go weeks or months with nothing then happens a couple of times in a day, I am always checking dash for battery light approaching roundabouts just in case

I'll get the temp sensor checked on VCDS then it's just weird how once the engine is started it reads normal.

Hmm Dave364 I wish we knew what was causing it. I would go dealers but with no fault codes present my car could be in there for many hours with no actual idea what's wrong and it's even worse that I cant even make the problem occur as its random.

Yeah I thought will just put up with it until it gets worse but never seems to get any worse tho, it's the same with me just random times it happens

I have had the same thing when slowing down at roundabouts etc and a couple of times at faster speeds, had been told could be interrupting a dpf regen but have had it happen twice in 2 minutes so would rule that out I think. Can go weeks or months with nothing then happens a couple of times in a day, I am always checking dash for battery light approaching roundabouts just in case

Thought you might like to see this review from honestjohn:

"With DSGs, protective software can delay the message from brake switch to ECU that brakes have been released, allowing car to enter a junction or roundabout on the fuel in the combustion chambers, then momentarily shut off mid-junction."