1.8 T single hesitation/clunk

[audi5inline]

Hello,

i'm new to the 1.8t engine, my car has a little problem.
Its a a4 1.8t quattro avant with 6 speed manual gearbox, enginecode BFB
When i drive at low rpm there are no problems.
When i, lets say drive in 4th gear with 3000rpm and then shift back to 3th gear 3500rpm and than give some throttle, i can feel a single clunk/hesitation before the car takes of, when i rev the engine to lets say 4000rpm and then go back on the throttle there is almost no hesitation, its only there after a downshift.

what i changed:
-spak plugs
-engine mount
-snub mount
-air filter
-pcv pipe under the manifold
-pcv check valve under the manifold

- Checked diff mount
- Checked gearbox mount

it seems the problem is only present with the engine warm not there when cold. there are no fault codes, idle is also stable

Could this be a bad coil ?
any clues?

 

[vivalacoulter]

If the coils were going then the engine management light would flash to signal a misfire I believe. Do you know when they were last changed?

 

[audi5inline]

They are the original and have never been changed.

 

[vivalacoulter]

Then it could possibly be worth replacing them, but if there's no code coming up I'd be inclined to leave them for now.

 

[audi5inline]

There is indeed no code. The car takes of when i push the pedal, and after about half a second i get a single clunk/hesitation. So i think that rules out the drivetrain mounts...

 

[Ian2012]

if it is coil packs then it's worth trying audi cos there is /was a recall for them, had ours done for free, have you scanned the car codes?

 

[audi5inline]

Yes no codes, i will try new coil packs this week and report back

 

[Mav190sline]

Call Audi. Had coil packs replaced on my 04 a4 2 years ago and 01 s3 3 months ago. Both f.o.c

 

[Mav190sline]

Recall no 28e9 if I remember correctly

 

[audi5inline]

changed coils yesterday and the problem is still there, i'm really thinking this clunk when i go on the throttle could be caused by the dual mass flyhweel...

 

[audi5inline]

any clues ?