feels like it cuts out / hesitation

[JonA]

Hi

on our a3 2L tdi (170hp) there is a bit of an issue that I am struggling to get to the bottom of.

in usual driving it all runs very smoothly, pulls nicely and all seems well, but when you ask a bit more . ie put your foot down, it pulls really well then at about 3400-3500rpm there is a big hesitation feeling almost as if it cuts out for a split second then back to full power.  If you hold the throttle down these carries on as it accelerates hesitating every couple of hundred rpm or so.

Garage tells me there are no fault codes - the crank shaft sensor was showing a fault but this has now been replaced and all seems cleared.

Anyone have a similar experience and fix or advice?

 

regards

 

 

[Trevor]

It could be turbo related as this is around the rev range that it should go onto boost.

Maybe run some cleaning additives through the fuel and also through the turbo to eliminate it

[BiPolarGhost86]

12 hours ago, Trevor said:

It could be turbo related as this is around the rev range that it should go onto boost.

Maybe run some cleaning additives through the fuel and also through the turbo to eliminate it

I agree with this. There is a company that comes to your home/work and completely carbon cleans your engine. Maybe worth looking into. 

[rbdazza]

I assume you've checked the basics and at least replaced the fuel filter?

 

i wouldn't go paying out for a carbon clean just yet but a bottle of redex or the like certainly would be worth a try. 

[JonA]

Hi

sorry for delay in coming back

I've previously run a liquimoly diesel purge through and changed the filter.  this had no appreciable effect.

 

[Trevor]

Onto the turbo cleaner solution or Terraclean then....that should sort it

[Dan3222]

I actually think it sounds like the turbo impellar is vibrating at higher revs. Just due to wear, it comes into contact with the sides. Obviously first step is to clean but I do think you will to replace turbo before long.

look up Wheeler Dealers Saab turbo episode.

is your car between 60 - 70k by any chance?

 

 

[JonA]

hi

the cars done a little over 100k ....