2.0 tdi 170 under boost issue...

[Ahun7er]

My car is almost in a sort of limp mode as it has no power after 3000 rpm.

I have had the vagcom diagnostics ran on it the other day and it was showing underboost.

I have changed the MAF and EGR within the last 6 months so can almost surely rule these out.

The mechanic is suggesting a DPF clean and forced regen.

Any ideas or suggestions for this?

Thanks.

 

[Jozeph Abuaglain]

Vacuum actuator on intake manifold, Audi offer a repair for it, it’s very cheap. Hope this help.

 

[Ahun7er]

Thanks for that. I tried this last week and it's made no difference. Have had it in the garage who believe the DPF is partially blocked and due to this the turbo can't boost after 3000rpm when the engine is warm.

Looking at a costly DPF

Would the DPF dash light show if this was the case?

 

[Jozeph Abuaglain]

Yes, what is your engine code ? DPF light will show if it’s clogged, how ever you are better off feel deleting the DPF.

 

[AvantMike]

You may be able to have the DPF sent away and '******' clean. Far less costly than a new DPF. Mine had this done almost 12 months ago with a blocked DPF caused by EGR issue.

 

[John Clutton]

before you spend loads replace fuel filter. just did that and what a difference, now I have boost pipe leak. :-(

 

[AvantMike]

That sucks! Mine had a few things done at around the same time, including fuel filter so not sure which one helped. It's certainly nowehere near as bad as it used to be but regen is still obvious on occasion. I was told by one tuner/garage to do two fuel filter swaps in close succession to clear gunk out of the fuel system.
Sorry you're chasing the issue @John Clutton - how easy is boost pipe to sort? (next to no knowledge on my part).

 

[John Clutton]

@ AvantMike I paid £34 for the boost pipe and 20 for a fuel filter. having boost pipe fitted next week filter change has made a real difference in performance......revs freely, no shudder and fuel consumption back to how it should be and very fast. so in all ive had a new throttle body, new fuel filter and then a boost pipe. I hope this helps before you scrap your car (like I was) please change your FUEL FILTER.

 

[AvantMike]

@ AvantMike I paid £34 for the boost pipe and 20 for a fuel filter. having boost pipe fitted next week filter change has made a real difference in performance......revs freely, no shudder and fuel consumption back to how it should be and very fast. so in all ive had a new throttle body, new fuel filter and then a boost pipe. I hope this helps before you scrap your car (like I was) please change your FUEL FILTER.

Thanks John - I had this recommended to me last year so already done, however I think I'll replace fuel filter again shortly along with a few other small jobs.

 

[John Clutton]

just had boost pipe fitted and now need an intercooler.