Once again my Octavia has gone into limp mode, this time it’s more concerning as I replaced the EGR valve under 12 months ago after much fault finding.

 

This time there felt like a ‘tug’ then the car went into limp mode without any warning lights or workshop message during a 90 mile drive.

 

Some background: The car is used mainly by my wife, she commutes only a short distance to work and generally the car does around 5/6k miles a year. Originally I bought the car for myself with heavier use in mind, however I’ve since had the luxury of a company car. I’m mindful that this ‘under use’ my be an issue with carbon build up or is it more of a dreaded turbo issue?

 

 

You have just answered your own question, The car is only used for short distances, A diesel engine needs to have a good thrash now and again especially to clean the crap out of the turbo, Mine does about 130 miles a week going back and forth to work and the turbo is a constant problem with limp mode, I 've tried every in tank cleaner and none of them work very well.. Get the car onto a motorway and give it a good run, get up to red line a couple of times when hot, It should help,, But short journeys are the best way to kill a diesel...

Sounds like overboost protection, almost certainly the turbo vanes are restricted. This happened to my car (also a low use BKD), but doing the "mr muscle" oven cleaner treatment has solved it and 12 months on it's not happened again.

 

Press on the actuator for the turbo, I bet it's seized.

I use Forte's Turbo cleaner once a year on long trips (100+km). With the engine warm, I'll give it a good run till the red line to clean all the crap (hopefully)

 

So far, my car has never gone into limp mode. Still with the original turbo and 263k miles on it (420k km)

 

Tank cleaners like Forte usually work to prevent, but don't cure it when there is too much carbon build up.

You might try the mr muscle treatment in that case (And from there on I would suggest a regular additive to the fuel once a year or so

+1 for Mr Muscle enema, Lidl oven cleaner works just as well.

another +1 for the Mr Muscle, a couple of years ago I did my daughters and a friends wifes BKD golfs. Both did lots of short journeys and up over 150k on the clock. I've got the routine down as I've had to do my daughters one again since. I have a piece of ply with two blocks on the back so I can wedge it between the turbo and exhaust pipe without trapping the silicon hose that's connected to Mr Muscle. Once I've squirted the oven cleaner in from underneath I can get the open end of a small spanner over the top of the actuator arm and move it a few times, go have a cuppa, move it some more then bolt it up, brake cleaner to remove any excess oven cleaner, and take it for a drive. Lots of smoke and eventually the eml light goes out and its good again until the short journeys cause it to happen again.