270 CDi

[MercedesLV]

Hello!

So I have this problem with my 2.7 CDi engine: since I bought it 4 years ago, engine has been running perfectly fine. ~ 2 years ago engine started to tick. There is this annoying tick coming from top of the engine (cylynder head area).

Jobs I have done to stop the engine tick:

• 3 times the injectors were taken out, rand on test stand and repaired if some of them were faulty. Tick still existed after these repairs.
• One time the rocker cover was taken off and the camshafts replaced, because one of the lobes had gone round. Week after this repair tick appeared again.
• Replaced the faulty accessory pulleys (alternator, belt tensioner etc.) because I have read, that they can cause some weird sounds too.
• Recently added and oil additive which, as mechanic suggested, will solve my ticking problem. Problem still exists.

The engine oil is changed every 11K kilometrs and only BOSCH filters are used. When I was draining oil, did not see any metallic particles in it, which would suggest of worn engine.

Engine does not "eat" oil. I'm using only good oil (MOTUL).

Solutions I have heard from people:

• Change hydraulic lifters, but it was done when cam's were replaced and week after that sound appeared again
• Flush the fuel injectors, because they could be noisy and cause ticking (and to be honest tick is coming from injector area)
• Change timing chain or the chain tensioner only. But as far as I have heard, timing chain on these engines last a lot
• Just drive the car and ignore the noise. If engine fails, replace it with another... not the solution I wan't

So I want to hear your opinion what to do with that engine...

Inserting video of engine sounds so you can understand what I am talking about.

Noisy engine.

Thanks in advance.

 

[BlackC55]

That does sound like a mechanical tick. Like a lifter. It sounds twice the crank speed.

 

[Yuri84]

Hi. What i would do if suspected injectors is disconnect one at a time while engine is running and that should point out faulty one if its there.
What i think might be your problem is either lifters or actual seat in the head where lifter goes. It is possible that seat is worn and lifter wobbles in there.
Also it is very possible that new lifter failed,especially if it was not high quality bits.