Dealer software upgrade. Worth the extra cash??

[storey_3000]

Evening all

My 07 2.0 diesel avensis is due a 90k service soon. Just lately it seems to idol a little low causing the car to vibrate both internally and externally, arm rest and dash rattle inside, exhaust rattles outside (very annoying and embarrassing!) 

Anyway, I normally use the local reputable garage for my services and mots as I don't see the point in splashing all that extra cash at a main dealer on such an old car. 

However, I'm wondering if the idol problem would be something they might pin down with one of the so called software updates that only main dealers car do with the latest Toyota equipments etc. 

Unless anyone has any ideas what could be causing the rough idol? I tend to run the AC all the time just to keep the revs a bit higher to stop it. Car drives lovely and smooth, loads of power, no hesitations or smoke. 

Any ideas? 

[frankie406]

Run a injector cleaner thru and check/clean maf sensor throttle body egr .how's your dmf?

[storey_3000]

Ok I'll try that thanks. 

I assume you mean dual mass flywheel? Umm, I'm not sure really, think it's good ha. How would I know if it's related to that? What are the symptoms? 

[frankie406]

The dmf when going bad goes "off balance" sort of breaking up it shudders/vibration.