2006 E320CDI Injector Question
Now I have a slight engine vibration that bothers me.
Engine mounts were replaced with Lemforder 48,000 km 30,000 miles ago.
My Independent Mechanic thinks they have failed again but also tested the injectors with the star diagnosis and found the injectors 3 and 6 were constantly fluctuating, or being adjusted constantly by the computer.
Being less expensive and also rationally making sense the motor mounts and transmission mount were replaced and solved 80% of the vibration. Lemforder parts again.
Being a perfectionist I would like it perfect. QUESTION are injectors 3 and 6 operating normally as the computer optimizes there performance constantly?
QUESTION are injectors 1, 2, 4, and 5 completely out of specification and the computer is adjusting them to the maximum and they are still out of specification so they are not fluctuating around the optimum value? Or are injectors 3 and 6 faulty?
Do I replace 3 and 6 or replace 1, 2, 4 and 5 or do them all or live with it?
Is there another test that should be performed or another component that should be looked a first? Fuel filter is 3,000 km 1,900 miles ago.
In summary should I do all injector, some injectors, test more, live with it or look elsewhere?
Thanks, Wishing all a very Merry Christmas and a Happy, Healthy New Year.




But my take on MM replacement is "if in doubt- replace them".
what at this mileage I would also extend to injectors.
Merry Christmas.
If you have European connections, you can have Bosch-certified rebuilds for about $100
Last edited by kajtek1; Dec 24, 2025 at 05:55 PM.
Sorry to hear about the short-lived Lemforder motor mounts. Are those OE for your vehicle? I have heard grumblings about Lemforder quality declining over the last several years, but not sure how accurate that is. (I just overhauled our front suspensions for our GL and e90 3 series with Lemforder parts so hopefully the quality is great!). I’ll be doing motor and transmission mounts on our GL soon, and probably will go the genuine part route.


