ML 270 Black oil leaking / Piston
 

Hi Everybody

A good day.

I have made a post sometime last year Dec 2007 regarding my 2002 ML 270 problem.

Black oil leaking from the ventilation hose ( Engine to turbo unit ). At that time my car millage was only around 71000km. Merc authorized service center has advised

1)Changed the air filter
2) Clean the manifold & caused the manifold spoiled.

3) Dismantle & checked the engine many time ; For nothing !

3) Change ventilation hose ;Harden ventilation hose, caused the oil ( blow by gas they claimed ) leak from the joint of the ventilation hose.

After changed 2 Brand new ventilation hose, leaking is still persist. Now they bring the compression test machine & test my engine. Result as follow ;

Sorry for the delay in giving you the test result. Please find attached the compression test recording chart (refer fig 1). The result shows cyl. 1: 17.0 bar, cyl. 2: 19.0 bar, cyl. 3: 18.0 bar, cyl. 4: 17.5 bar, cyl. 5: 17.5 bar. Please also find attached the MB standard compression pressure figures. Based on your actual engine compression figures, the normal standard compression tolerance value should be between 29 to 35 bar (refer fig 2). The compression pressure wear limit value should be around 18 bar. Since your engine actual value are between 17 - 19 bar, these figures are at minimum wear limit value.

As you mentioned in your earlier email, there is some engine oil leaks, please arrange your vehicle for us to inspect if the leak is still from the air breather hose or from some other area.

During the compression test done recently, the compression pressure wear value are all at the minimum wear limit value of between 17 - 19 bar. This will increase the blow-by pressure due to some slack of the piston ring. Thus, there will be more blow-by gas escaping from the top breather hose. The top breather hose is originally fitted to the turbocharger air intake hose. The turbocharger unit is cooled and lubricated by the engine oil.

My question

1) ML 270 piston is so fragile ? Only run for 70000km ? I heard many of the ML 270 facing the same problem, is it true ?

2) Blow -by gas / black oil from the engine ; will cool by the turbocharger & work as lubricant for turbo charger ?

3) How true is the figure they have provided ? I'm not familiar with all these. Please help.

Is a nightmare for me to have this ML 270. Suffered for 2 years on black oil leaking problem.

Regards

KS Audio

RE: ML 270 Black oil leaking / Piston
 

Really ? We found tan of problem for ML 270 in Malaysia. Especially piston issue