Audi A3 - Audi A3 1.8T AGU violent judder/lurch under accele - Nick Mazda 6 TS2

Hi guys,

I have Another problem with my Audi A3. Its a 1.8T AGU Engine with 102,000 miles on the clock.

Its hard to explain but it every so often when I accelerate hard from a slow speed the car violently jerks, almost as if I had jabbed the brakes. It feels like the car is trying to stall but then picks itself up and is fine for a while, it also seems to do it when I am only just touching the accelerator at slow speed. It isn't a continous jerk when accelerating hard, just one big sort of "lurch" but when only slightly accelerating it carries on for longer until I accelerate a bit more or change gear. I have only really noticed it in 1st and 2nd gear, it seems fine at high speeds in the other gears. I also noticed tonight that the average MPG reading on the digital display dropped right down and is gradually building itself back up again.

Due to just buying and doing up a house I cant afford to take it to a garage, my old man who is a retired police mechanic can't figure it out so it's doing my head in!

I have tried various things to sort it, Maf sensor, Lambda sensor, Ignition amplifier module and tested the coil packs but have had no joy! The car is regularly serviced and was serviced approx 6 months ago which included oil, all filters and spark plugs etc.

Any help would be MUCH appreciated!

Thanks Nick

Audi A3 - Audi A3 1.8T AGU violent judder/lurch under accele - Roly93

I dont think it would be any of these (Maf sensor, Lambda sensor, Ignition amplifier ) that would cause this type of symptom especially if the car idles okay I assume ?

One avenue to explore would be an intermittant throttle potentiometer/throtle body, give the highish mileage of the car.

Audi A3 - Audi A3 1.8T AGU violent judder/lurch under accele - madf

Throttle body carbonned up?

Audi A3 - Audi A3 1.8T AGU violent judder/lurch under accele - Nick Mazda 6 TS2

Sometimes when it idles the Rev's drop to almost stall but then picks itself up after a few seconds. I have cleaned out the throttle body with carb cleaner but this has made no difference. If it helps, I noticed last night that the average MPG reading on the digital display had dropped right down to 12MPG since earlier in the morning but quickly started rising back to the usuall 32ish region again...It did this before when it was playing up too!

Its doing my head in as its uncomfortable when it lurches and Im worried im going to break down miles from home eventually!

 

Value my car