Hi there, First post! I have just bought a C450 some weeks ago and have been having issues with power delivery. Apparently a known issue on this model even though I haven’t been able to find anything on it in any forums, hence, this post The symptoms were somewhat difficult to detect, but was basically a varying power delivery. It was only because the power meter wasn’t showing the full 270 kW in all gears that I suspected there was a problem. When the car has not been pushed for a while, it would deliver the full 270 kW (on the power meter) in 1st and 2nd, around 250 kW in 3rd and no more than 200 to 220 kW in all other gears. I have a carly adapter which gave me three error codes but no explanation: P026E71, P026E7A and P026E92. No CEL or any other indication that anything is wrong. Took it to the garage and they have found out that the intercooler cooling system was missing 1,2 liters of fluid and after further investigating, that the intercooler had delaminated internally causing water to slowly leak into the charge air. The codes were related to reduced boost, low fluid level in the reservoir and the circulation pump for the separate intercooler cooling system, but none of them resulted in a CEL, just reduced boost and thus power delivery. Fortunately, there was no engine damage as the leak was slow and the water has most likely just evaporated in the engine, however, the technician was concerned that if they refilled the reservoir, a more severe leak could develop, so they kept it and gave me a C200 loaner. They are replacing the intercooler (£400) and the circ. Pump (£200) which seized due to no fluid. Should have it back monday. Anyway, as I couldn’t find any info on the issue online, I wanted to share my story. So look out for a slightly sluggish throttle response and an empty reservoir (the one on the front of the engine, under the cover on the left side). Anyone else who have experienced this?