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MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3567
Experience:  Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes
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My MLwith 121,000 just started making a horrible knocking

Customer Question

My ML(###) ###-####with 121,000 just started making a horrible knocking noise when it is started when cold It does not do this all of the time . It is way louder than a lifter raqttle
Submitted: 5 months ago.
Category: Mercedes
Expert:  Chad Farhat replied 5 months ago.

Hi my name is ***** ***** I will be assisting you

Expert:  Chad Farhat replied 5 months ago.

is the oil light coming on when the rattle starts ?

do you change oil regularly ?

does the check engine light comes on when that happened ?

let me know thanks

Chad(aka -Jhook1398)

Customer: replied 5 months ago.
oil light does NOT come on when rattleing
Oil changed every 13,000 miles per directory just changed 3000 miles ago
check engine light does NOT come on
Expert:  Chad Farhat replied 5 months ago.

do u experience lack of power ?

any smoke ,using oil or all good ?

Customer: replied 5 months ago.
no lack of power, I shut it off when it rattles wait a minute and rstrt and noise is gone
it has lots of power all the time
The vehicle NEVER SMOKES and uses NO OIL
Expert:  Chad Farhat replied 5 months ago.

it is kind hard to tell for me with out hearing it , i m wondering if timing chain tensioner but you will hear all the time

but when u cycling the switch and going away , it will be intake camshaft solenoid or position sensor , or a module resetting g resetting and gives power back to a sensor or actuator for the timing components , so would say it is more of loud noise from top of engine or bottom or you can tell .

if you have somebody with a capable scanner , you can check for any history codes and run a variable timing actuator test, since you change oil regularly and assuming you use synthetic oil there is no reason for oil pump or oil sludge issue .it is more of electronic than mechanical from what u describing

Expert:  Chad Farhat replied 5 months ago.

how often does it happens ?