Misbehaving engine after puting petrol in diesel engine

[ianbryant]

Unfortuantly we put petrol into our 1.6 Bluemotion TDI MK6 diesel a couple of months ago, and drove for a while (i.e. until it stopped on the Motorway). The fuel was drained and filters changed, injectors cleaned etc. The Car runs okay for 98% of the time but occassionaly goes to limp mode whist driving (70 on the motorway) and the coil light comes on or takes 30 seconds to start after the start/stop has cut in and then shows the warning message on the instrumentation. If the car is turned off and restarted it runs normally again for the next 100 miles or so. i.e. this happens about once a week typically when the start/stop has cut in on very busy roundabout

My local garage tell me that its the Lamda Sensor gone, but at £150+ to replace as thats whats the computer tells them. Is the garage right, or is the sensor doing what it meant to do and detecting some other fault. Looking at various forums the usual thing to go here is the fuel pump - could it simply be that fuel is not being supplied as expected and hence the sensor detects strange behaviour.

I not sure whether to replace the lamda sensor or fuel pump - both are expensive!

[-M-]

You need to take it to a VW dealer as they can perform the correct diagnosis on your vehicle as well as check for any outstanding recalls and software updates both of which only they can provide.

There may be a problem with the injectors as it is known problem on 1.6 tdi's and there is a software update for this fault.