Hey there!

Can anyone please tell how can i tell which one i have in my c4 a6? My car originally had 2.6 110 kW, but the previous owner changed the engine to 2.8 142 kW one. He said he took the engine from some c5 generation a6.

But i want to be sure. I know there ain't any VIN on the bay. Are there any detail differences between c5 and c4 142 kw engines?

Thanks!