2007 2.0TDI Multitronic - Engine Shake/Judder on Hot Start

**jeboa** · 05-04-2011,12:16 PM

Open to any suggestions here!

My car has covered 80K miles and had a new gearbox 10k miles ago. The wrong oil used during service, and the box was replaced FOC by the (excellent, and honest) independant that carried out the service.

For about the last 5k miles it has developed quite a violent rattle when starting from hot. It never occurs when cold, and increases in severity depending on how soon after stopping the engine you start it again.

The closest thing I can equate it to is a broken engine mount. However, there is NO problem at all when driving or starting from cold. 'Gearchange' (CVT - so more belt moving than gearchagne) is as smooth as normal. No noise/judder under cruise or during acceleration.

Took it back to the independant and he has quoted <>£800 for dual mass flywheel replacement. Thing is, it doesn't seem to match any of the 'known' problems with a dual mass flywheel.

Anyone had any similar experience, or got any other ideas?

**shazbat** · 07-04-2011,02:05 PM

Hi,

I have similar issues - no new gearbox though - nobody else out there experienced this or offer any guidance?

Cheers,

Shazbat

**wolffie** · 08-07-2011,07:37 PM

Hi, my car seems to have the same issue. When warm/hot, when I try to restart the engine, it shakes for a second violently then remains idle or stops. I`ve heard some guys changed the battery and solved the problem. Have you found a solution so far?

**a8 tech** · 08-07-2011,08:58 PM

change the flywheel as this is normally the problem

**shazbat** · 08-07-2011,09:38 PM

It's an expensive fix - is there a definitive test/symptom or even better a VCDS fault code to look for? I'd hate to go to the expense of this and find it's still an issue!
Would value your input...

Cheers,

Shazbat

**wolffie** · 09-07-2011,10:11 AM

Originally Posted by shazbat

It's an expensive fix - is there a definitive test/symptom or even better a VCDS fault code to look for? I'd hate to go to the expense of this and find it's still an issue!
Would value your input...

Cheers,

Shazbat

Hi, Shazbat I thought you solved the problem since your first post was in april. No, the VAG-COM scanner returned that everything is fine at my car (Golf MkV 1.9 TDI 105 HP). Still my battery is a little tired, the measuring device stated: "Battery change recomended" . I`ve searched for this issue and the most successful cure seems to be replacement of the battery with a new one (at least 72 Ah for 1.9 diesels). Don`t know how to explain that but seems to work. Let me quote from another guy with the same problem:
"Hi wolfie.
Mine and sahar problem happened once the was hot and restarted whilst warm. The
engine did shake violently and make a very bad noise but it did not stop it did
always start....well mine did anyway.
I thought it was the starter motor and sahar had a part of his gound down (dont
know what bit) by a garage and they probably re-greased it while it was
apart...and his was ok.
I stripped down my starter and bought a used replacement and it did not sort the
problem. I accidently cured mine when I got a new battery.
If you want to try something for free try cleaning and regreasing your starter
if you can. After that measure you battery voltage see how that is.

hope this helps.."

As you see the guy did sort it out. I have similar answers on a forum in my country: replace the battery. Still, some warned me that may be just a temporary solution as the power of new battery masks underlying problems. Other succeses were on replacing the engine starter (very expensive

) and some claiming that the engine needs software remapping of some starting values as the cold starting fuel mixture differs from hot starts fuel mixtures. Anyway the problem seems to be related on this axis: weak battery - worn starter - bad reporting sensor of engine temperature - resulting in a wroong start.
Let me know if you find a definitely cure, as I will do the same. (sorry for bad english I hope you can understand what I`ve wrote).
My email is vallylupu@yahoo.com (if you want to write directly). This forum won`t allow even to PM if you don`t have at least 10 posts. ***? I am supposed to invent 10 posts just to earn the right to PM other user?

**shazbat** · 09-07-2011,11:35 AM

Battery you think - interesting...

To A8 Tech,

What are your thoughts on this - I know you know your onions when it comes to Audis - would appreciate your thoughts.

Shazbat

**a8 tech** · 09-07-2011,12:05 PM

if the cranking rpm is below 270/250 rpm then the injectors will not open so test the amperage of the starter under cranking and rpm speed (weak starter or battery or poor high resistance at the earth or 50 supply cable)

you can alter the ecu file if you have access to remap software for fuelling when warm in relation to crank degrees but this is not recommended and ruling out the basics would be my advise

if the noise is a clatter then it suggests the dual mass flywheel (mulititronic has this as well as the manual transmission)

also if the engine fails to start and is then followed by lumpy idle and white smoke then coolant is entering the combustion chamber

this caused by either a leaking egr cooler or a fracture in the cylinder head

so does it start first time and clatter > flywheel

or does it take a few cranks > low rpm or cylinder leakage

these are just some common issues and there are more but need specific description

**shazbat** · 09-07-2011,12:16 PM

Thanks for replying so promptly.

I'll warm her up and try to figure out which of the 2 it is.

Will post back with findings.

Again, thanks for your input - appreciated..

Shazbat