W164 ML320 Ticking near side engine bay

[Podwas]

Hi All,

I've not long bought a 2007 ml320 with full service history, but have noticed its developed a slight ticking noise from the near side engine bay.
The tick comes and goes and is only audible when at idle speed. Disappears when rpm is over 1000 rpm....any ideas please?

 

[Mark A]

Take the cover off the engine and have a good look for black tar like deposits, could be a leaking injector (search on here for black death - not as bad as it sounds). If nothing else it may help you narrow down where the noise is coming from.

 

[Podwas]

Hi Mark,

Have checked that already.....engine is clean as a whistle. Sounds like it maybe near the ABS control unit. Going to have another listen tonight. Have got an isoft MB fault code reader, hoping this will help identify something.
Have been browsing some forums about this topic....Might be ABS module, AUX Belt tensioner or possibly a cam lifter although I don't think its that as its disappears when revs are slightly increased.

 

[LostKiwi]

A sticky lifter will exhibit exactly what you're describing. An increase in revs is usually accompanied by an increase in oil flow/pressure so the ticking stops.

 

[Podwas]

What's the fix? It's just been serviced too

 

[LostKiwi]

What's the fix? It's just been serviced too

Sometimes they get better by themselves.
Some people swear by a hydraulic lifter cleaner added to the oil.
Other than that its replacement lifter.

 

[malcolm E53 AMG]

I remember 07 cars having a crankshaft bearing problem, suggest you read the thread below so at least you are aware and can check

http://forums.mercedesclub.org.uk/index.php?threads/main-bearing-problem-with-cls-320-cdi.71976/

 

[Podwas]

I remember 07 cars having a crankshaft bearing problem, suggest you read the thread below so at least you are aware and can check

http://forums.mercedesclub.org.uk/index.php?threads/main-bearing-problem-with-cls-320-cdi.71976/

Going to take it to a MB specialist next week. Hopefully it's not to bad! Warranty that came with car will cover it so they tell me

 

[Podwas]

Have taken it to independent specialists and Mercedes dealer and have the following results.
One Independent specialist have reported pulleys and aux belt as possible root cause. Another has said possible cheap oil at service causing tappet issue and main dealer reported crankshaft bearings.

 

[ajlsl600]

Hi Mark,

Have checked that already.....engine is clean as a whistle. Sounds like it maybe near the ABS control unit. Going to have another listen tonight. Have got an isoft MB fault code reader, hoping this will help identify something.
Have been browsing some forums about this topic....Might be ABS module, AUX Belt tensioner or possibly a cam lifter although I don't think its that as its disappears when revs are slightly increased.

could be hydraulic tappet if used on that model .my clk 320 petrol does a similar thing from cold ,once warmed up it goes quiet. would change them, but hardly worth it on a 130,000 mile 01 car