E270CDI engine rattling/knocking sound
Thread Starter
Newbie
Joined: Aug 2020
Posts: 2
Likes: 0
From: Hamar, Norway
W211 E270CDI Avantgarde
E270CDI engine rattling/knocking sound
Hey people,
I've recently gotten a slight problem with my 2003 W211 E270CDI, 180k miles. The engine has started to make a rattling/knocking sound. In the beginning I could barely hear it, but after 2-3 days of normal use the sound was really easy to hear.
First off, I thought it was the injectors/injector seals, so I've changed these and cleaned up the beginning "black death", but still no change.
4/5 injectors were new in 2015, all of them were inspected by a local injector repair shop and they were in good condition.
When I start the engine, the noise isn't there, but then after around 3 seconds it appears (possibly when it gets oil pressure?). It runs and accelerate smoothly with no loss of power. No significant amount of black smoke beyond expected, as it is stage 1 tuned.
Oil service has been done either before or at interval for this car before I bought it. During my ownership oil service has been done every 6200 miles.
No fault codes, no check engine light.
Noise at idle:
Noise during rev:
Anyone got any idea of what this could be?
- Håkon
I've recently gotten a slight problem with my 2003 W211 E270CDI, 180k miles. The engine has started to make a rattling/knocking sound. In the beginning I could barely hear it, but after 2-3 days of normal use the sound was really easy to hear.
First off, I thought it was the injectors/injector seals, so I've changed these and cleaned up the beginning "black death", but still no change.
4/5 injectors were new in 2015, all of them were inspected by a local injector repair shop and they were in good condition.
When I start the engine, the noise isn't there, but then after around 3 seconds it appears (possibly when it gets oil pressure?). It runs and accelerate smoothly with no loss of power. No significant amount of black smoke beyond expected, as it is stage 1 tuned.
Oil service has been done either before or at interval for this car before I bought it. During my ownership oil service has been done every 6200 miles.
No fault codes, no check engine light.
Noise at idle:
Anyone got any idea of what this could be?
- Håkon
Thread Starter
Newbie
Joined: Aug 2020
Posts: 2
Likes: 0
From: Hamar, Norway
W211 E270CDI Avantgarde
We've tried, it sound like it came from the front part of the engine, but we couldn't really hear it coming from the block with a stethoscope. Looks like we were right and that we drew a conclusion to early. If we had just removed the serpentine belt first off, a lot of time would have been saved. The whole problem was the harmonic balancer. At least the injectors are now fixed up 
Thanks for the help!!
Thanks for the help!!
