Need some help with the next problem

 

So car will be driving along fine with no problems. Then for no reason and with no warnings lights etc. Rev counter only will start to be erratic, speed of car or gear I am in has no bearing. As the rev counter is doing its thing the throttle is unresponsive and sometimes does make the car rev and sometimes doesn't. Car is jerky and engine speed stops dead. Which can be unnerving when doing motorway speeds and car just trys to stop dead.

 

Then after a couple of seconds all is back to normal. Sometimes it cuts out and starts fine straight away and again drives fine.

 

This problem happens as and when it likes no pattern to it. 

 

There are no fault codes had it scanned twice. No lights on dash when it happens. I've changes all filters and fluids recently and problem happened before and after this.

Car is an 2007 Octavis VRS Diesel

Any help or ideas ?

Edited 12 July, 20178 yr by mattcut

I've had a Zafira B do this and it was a bad connection on the fuel pressure rail. Different animal to the VAG TDi though.

 

What are you using to scan the car with?

Two different VCDS from two different places 

Sounds odd; but check the earth connections. Generally underneath the car and can get covered in all sorts of road grime which could lead to intermittent electrical gremlins. 

 

Quick fix if it is - but make sure you disconnect the battery first! 

Thanks will have a look tomorrow.

 

Just another note. On some occasions I can here a clicking noise, sounds like a relay or contact ?

Just to let you all know. 

 

The fault was a faulty crank sensor.