2003 C270 CDi Auto with sport pack.

[glaughton]

Hello
I have a really annoying problem any ideas?
The engine makes a metallic ringing noise loudest on very light load and is throttle dependant, and it kicks in as you come off the over-run, its like normal diesel noise but worse and very metallic,almost like pinking.
Over 50mph you can't hear it as the tyre noise is louder but i hate this noise. I bought the car last summer at mercedes direct in caterham. Under warranty they changed the engine management computer (alegedly).
Problem remains. I got a chap to put the autologic computer on it and it shows Fault P1354 Synchronisation between crank and cam EEK.
They guys at Mercedes Direct told me it had this and they had fixed it, YEAH !
SO, if the timing chain hasnt jumped a tooth what does this mean. It drives OK and fuel consumption is OK, just damned noisy.
I read a previous thread on E320 similar issue. I do have a scope and I am electronic engineer but how to test the crank and cam sensors without a wiring diagram and knwing what wave form and voltages I am looking for?
In fact where are the sensors, i cant see them? I have no idea if my noise is caused by this fault or not but its my only hope else i am going to have to sell the car, the noise spoils the drive, its a real shame.
Please help as i am at my wits end with this.:-(

 

[shaungriff]

try this link to help with using your scope mate http://www.swangate.com/picoautomotive/waveforms.html

 

[BlackC55]

Ignore that fault code. You will be chasing your tail if you try and test them. That code always comes up and its nothing to worry about. Your noise is unrelated to this I suspect. Take it back to MB and complain that when you took it in they didn't fix it. You have a case I am sure

 

[glaughton]

thanks guys, I will look at the waveforms. I did take it back twice and they had the car for 7 weeks from last Christmas. They lent me a nice 2006 car so that was OK. Anyhow, they treid to fix it and in the end when i asked for my money back after 7 weeks they just said its acceptable for a used car. Well it might be for a £3000 car but I paid £14000. So its no acceptable to me. Its not that bad but its not right. I know it should be quiter as this is the third one i have owned of the 5 cyl 2.7's the others did not make this noise but i test drove an 04 last week and that had the same noise. So maybe some are quiter than others.
Anybody else have any ideas? It also appears the rail pressue goes upt o 500 Bar on reving to 5000 is this normal? Should it regulate? the computer only tested at lowish revs but when i revved it the pressure goes sky high,not sure if thats correct or not. It may be a red herring.

 

[glaughton]

OOPS I meant 2000 rpm not 5000, it would have exploded I am sure !

 

[BlackC55]

The fuel pressure you are seing I believe is normal.

Has your exhaust got the flexible section at the front. It is like a woven mesh section about six inches long.

These are prone to being noisey and give a metalic noise you are describing.

Have a look underneath.

 

[glaughton]

thanks for your reply
I dont know about the exhaust. I will have a look at the weekend, its lowered so its really tricky to get on my ramps, i will have a go on saturday. Thanks again. Thinking about it, what happens, does it get thin by errosion or something? I think my noise is combustion related, its either pre ignition or post ignition but how can this happen its a diesel, its wierd, but i guess if the exhaust was dodgy it could make this noise. I was told the injectors can get blow by up the seals so atmosphere, but i am worried about taking them out just for a look see in case i damage something if they are stuck in. I am trying all ideas. I will check the exhaust on Saturday after i have changed the oil on my other halfs VW Bora, what fun.

 

[BlackC55]

You don't live that far from me. Do you fancy a trip to Portsmouth? I could have a look for you......?

 

[glaughton]

yes great thanks, are you in this business or is this a hobby for you?
i can come to portsmouth but not sure when, my daughter is at uni in southampton so its on my route. my email is glaughton@btopenworld.com if you can email your phone number or we can do it by this forum. maybe monday or i have a day off on 25th as not sure what i'm doing monday coming. thanks

 

[BlackC55]

Just started as a specialist. Long story..... very long.

Email sent. Give me a buzz soon