My bosch dishwasher is quite a old one. It has a mechanical timer rather than a electronic one. When its finished it's cycle it seems to be very very hot inside. The plates cannot be touched their so hot and steam whooshes out upon opening. Even on the lower 50c setting its really hot.

Is this normal or has some temp sender gone wrong?

Not too sure but I guess normal.

If I open mine up before its cooled down I dont think I would be able to touch the plates. 50deg is hot hot!!

sounds normal to me, mine is newer and is exactly the same,... except of course I thought that they were to be used for cleaning car parts

Get on the phone to the Bosch technical helpline, there was aservice bulletin a while back for some Bosch dishwashers with a fault that could cause it to catch fire - Very rare only one or two recorded incidents but it would be as well to check it out. Remember you only get steam above 100 degC

steam is invisible, water vapour - below 100C is the stuff that you can see,...

dishwasher superheat water to something like 130 degrees. i dont see how a domestic dishwasher would be able to heat it any higher than this?

dont panic,the fire scare concerned models well after yours and didnt have mechanical timers.
The heated rinse is normally 65 degrees and the residual heat in the washed items drys them .
Do not open the door for thirty minutes after cycle has stopped otherwise the drying process is spoilt.

Yeah, think I'm remembering the temperature in F not C!