Hi guys,

 

My parents have a 2005 Octavia 2.0 TDI (PD140/BKD engine), which recently failed its MOT on emissions with a smoke reading of 0.9 (target required is 0.7) - diagnostics indicate that the turbo is over-boosting due to sticking vanes.

 

Before they look at one of the cleaning services, is there a DIY fix for this?  I've seen Mr Muscle Oven Cleaner recommended elsewhere, but I'm a bit leary of this (purely because it's using it for a purpose it's not intended, even if it's the right chemicals ...)

 

Thanks!

 

P.S. It's run on V-Power (or ESSO equivalent), and has had a dose of Forte Diesel Treatment and an "Italian tune-up".  Other than the slightly higher-than-allowed smoke reading, there's no symptoms of anything being wrong.

You could try some Archoil AR6400-D MAX, which you add to the fuel.  Also is the air filter in good condition?

I had the Overboost/limp home mode issues on my BKD a few months after I got it, and did the mr muscle clean. It really did the trick, haven't had limp home mode in the 4 months since I did the clean.

 

I'm quite skeptical of the turbo cleaners you put in the fuel or air intake, as they need to survive the combustion process and then clean the turbo on the way out. The oven cleaner method sits directly in the turbo for as long as you like, and the results are instant.

 

For the smoke reading, try taking the air filter out for the MOT

 

18 hours ago, wiilydog said:

You could try some Archoil AR6400-D MAX, which you add to the fuel.  

Cheers

 

18 hours ago, wiilydog said:

Also is the air filter in good condition?

Brand new

 

5 hours ago, chrisund123 said:

I had the Overboost/limp home mode issues on my BKD a few months after I got it,

Frustrating thing is, they're not getting limp mode, just a bit more than is allowed of smoke high up the rev range.  

 

5 hours ago, chrisund123 said:

I'm quite skeptical of the turbo cleaners you put in the fuel or air intake, as they need to survive the combustion process and then clean the turbo on the way out. The oven cleaner method sits directly in the turbo for as long as you like, and the results are instant.

I understand and share that scepticism

 

5 hours ago, chrisund123 said:

For the smoke reading, try taking the air filter out for the MOT

Tried that. :(  First time with a new air cleaner, retest without one - didn't seem to make a difference. :(

 

Edited 31 July, 20187 yr by martinch

As you have not seen the main result of sticky vanes (going into limp mode on high demand such as accelerating hard or going up hills) I would look elsewhere for over fuelling. In particular I would clean the MAF. If not that, then look closely for air leaks after the turbo, such as around the air cooler and associated pipe work. 

 

1 hour ago, pikpilot said:

As you have not seen the main result of sticky vanes ... I would look elsewhere for over fuelling. In particular I would clean the MAF. 

The MOT-man had suggested temperature sender.  I must admit, I'd not thought about the MAF - will give it a go - thanks.

 

1 hour ago, pikpilot said:

If not that, then look closely for air leaks after the turbo, such as around the air cooler and associated pipe work. 

The first time it was tested, there was a whistle on throttle-off, and oil around the end of the pipe.  They cleaned the area and replaced the seals in the turbo-to-intercooler pipe, and it went away.  Probably should do some further checking just to make sure the pipework's OK.