Audi A4 2.0 Tdi 140 2006 B7 - uneven tickover

[CharlieG]

Hi folks - my first post!

I have just recently bought a mint Phantom Black A4 Avant 140 Tdi S-Line with 64k miles.

Everything about the car is fine except that the engine has an uneven tickover. If you increase the revs to ~1000RPM, it becomes smoother. Normal driving and acceleration all appears fine.

No error lights are apparent and there is nothing to suggest a fault.

For those of you who have more experience of the B7, what would your advice be? I bought the car from an independant trader and it comes with (limited) warranty, but I am interested in the Forum Member's views and advise before doing anything.

Many thanks.

Charlie.

[CharlieG]

Replying to my own post!

I have picked on the the other existing threads under 'lumpy idle'.

Looks like a few issues to investigate.

I will start with the fuel filter/fuel pump items first though!

Thanks.

[winnie070383]

Replying to my own post!

I have picked on the the other existing threads under 'lumpy idle'.

Looks like a few issues to investigate.

I will start with the fuel filter/fuel pump items first though!

Thanks.

i have the same and have learnt that it is a charitaristic of that engine, most say it is to do with the balance of the flywheel weights, just sit back and enjoy the ride

[a8 tech]

The term is egr bounce caused by exhaust gas recirculation however there are some issues with excess egr or fuel pressure but if these are ok its egr bounce and unavoidable

[mya4audi]

The term is egr bounce caused by exhaust gas recirculation however there are some issues with excess egr or fuel pressure but if these are ok its egr bounce and unavoidable

My A4 also suffers from egr bounce and i have learned to live with it. Can you tell me is there a software update that that sorts out this characteristic?
Sorry to hijack this thread but i wanted to ask A8tech a question.
i recently had a head light problem sorted out and the tech disconnected my battery, since then when my car is hot it is hard to start and makes a terrible noise when starting. I took the car to garage today and the guy said the noise was engine shudder because the engine didnt start, which strangely i felt better about. But there is still the problem of the engine starting intermitently from hot. Todays guy said he thought the problem was probably some thing to do with the egr valve reverting to default setting?? could this be the cause?? if so whats the fix??
Please help

Mike

[a8 tech]

Basic settings of exhaust gas recirculation
MVB 3
1) Start engine
2) Start basic settings
3) Idle speed
The difference
of actual EGR must be between
EGR active and EGR inactive
at least 120 mg/stroke

There are a few sw updates for egr and fueling but I need your current ecu data

poor starting could be early signs of fuel pressure loss which can be checked by taking a sample of fuel from the fuel filter and checking for excess soot.

If the engine cranks slow then check the battery is in order, if there is a noise from the starter or flywheel then this could also be a sign of dmf failure.

In some cases the internal grease from the dmf can be seen around the gearbox bell housing or starter motor which indicates failure or the early signs.

[mya4audi]

Basic settings of exhaust gas recirculation
MVB 3
1) Start engine
2) Start basic settings
3) Idle speed
The difference
of actual EGR must be between
EGR active and EGR inactive
at least 120 mg/stroke

There are a few sw updates for egr and fueling but I need your current ecu data

poor starting could be early signs of fuel pressure loss which can be checked by taking a sample of fuel from the fuel filter and checking for excess soot.

If the engine cranks slow then check the battery is in order, if there is a noise from the starter or flywheel then this could also be a sign of dmf failure.

In some cases the internal grease from the dmf can be seen around the gearbox bell housing or starter motor which indicates failure or the early signs.

Sorry but all that stuff blows my mind. I wanted to know if the suggested cause was most likely causing my symptoms or was it just a stab in the dark. I'd love to be able to give you the info you require but i cant seem to get anyone with Vagcom close enough to me to use their unit. The headlight guy was in suffolk 200m round trip! I'd take it to him if i thought he was able sort this out. I could take it to Audi bromley (nearest) but i'm frightened of the bill!!
The engine turns over at normal cranking speed and there is no grease around the bell housing or starter motor. Dmf failure frightens the s*** out of me.
For the record = A4 Avant 2005 2.0ltr tdi 7 speed auto.
Mike

[a8 tech]

Ok, the multitronic ( 7 speed auto) uses a flywheel/ring gear similar to a dual mass and over time the spring loading plate loosens up causing a metallic noise when cranking and this sounds like your problem.The flywheel is not to expensive but the labour is around 7 hours remove and install.
Best pop into audi for them to look at it

[mya4audi]

Ok, the multitronic ( 7 speed auto) uses a flywheel/ring gear similar to a dual mass and over time the spring loading plate loosens up causing a metallic noise when cranking and this sounds like your problem.The flywheel is not to expensive but the labour is around 7 hours remove and install.
Best pop into audi for them to look at it

Thanks for that A8tech.
I will get over to Audi asap. One final question if it is as you describe it may be,wouldnt the metalic sound be heard when the engine is below 90c. This only happens when the engine is at 90c (normal running temp for my A4) and not b4?
and not every time i turn the key either?

Mike

[a8 tech]

even more likely to be the flywheel