Hi all. The guys over at Pistonheads suggested I should post here and ask your views on my piston problem
About 2 weeks ago my car (SL55 AMG, 2002, 96k miles, unmodified, FMSH) developed a misfire which I thought would perhaps be a coil pack or something simple. My local Mercedes dealer diagnosed low compression on cylinder 7, and after further investigation discovered that the piston had cracked in half which is apparently unheard of on these engines.
I'll post up some pics of the cracked piston below. It's actually cracked right across the face (which is 9mm thick) down the sides and across the underneath of the face, including the tops of the holes for the gudgeon pin. The only part that doesn't show any visible crack is the underneath of the pin holes.
I wondered if there are any engineers about? Your opinions would be welcome
Is it likely to be a one off event caused by a slight fault from manufacture? Or what other reason could have caused it? I could perhaps understand it if the car had been running on increased boost and a remap, but it's always been completely standard and meticulously serviced by Mercedes in Weston Super Mare.
Some people have suggested that AMG would want to see the piston to try and diagnose the problem, so I emailed them at "email@example.com" but haven't recieved any reply - does anyone know if that's the correct email address?