New member here, I have recently bought a 2002 Mercedes 230 CLK in Obsidian Black with 77,000 miles on the clock. Recently the engine management light has come on the dash and the car is returning less than 20mpg from an average of 30mpg+before the light came on. An ex mercedes tech has told me that oil has made it's way through the wiring loom from the variable speed sensor on the crankcase to the ECU unit. He says the seal on the sensor has failed. He also noticed that a clicking noise from the crankcase indicates a broken spring on the camshaft split cog tensioner. He reckons it's an expensive fix. He also reckons the Kompressor is noisier than normal but not to worry about it too much at this time. Are these common CLK problems ? The car's performance seems ok but it's definately not fuel efficient. Is there a simple fix to get the car back to normal fuel consumtion ?A bit long winded but I hope someone can help.

 

Hi,
Another guy had the same problem (oil in ECU) on an SLK230 earlier this year. If you trawl the website you will be able to locate his post.

Since the CEL (Check Engine Light) is ON you need to get the DTC's (Trouble Codes) present on the ECU read? This will give extra information regarding what the problem is.
Looks like you may need a new ECU however.

Stuart