compressor hot and fridge/freezer noisy

[Continental]

My 18 month old AEG frost free fridge freezer has begun making horrible 'grinding and scraping' type noises from somewhere within the freezer unit. They seem to continue throughout the night mostly. I've no idea how the unit 'knows' it's night time, perhaps it's because the door isn't being opened much then.
A few months back (also just out of the warranty period) the whole thing overheated during a warm spell of weather and both temperature displays (+4 and -18 deg) went well above their set values. I noticed the single compressor unit was getting too hot to touch (about 50 deg C) and since then I've kept a fan blowing on it. If I remove this fan the compressor gets very hot and I'm worried the whole thing will fail again but maybe I'm actually causing some kind of problem and leading to all this noise. Can anyone help? Thanks.

[spimps]

You may have a defrost problem of some sort,it's likely the circulation fan catching on a build up of ice behind the back panel in the freezer.
You could unload and switch off and leave with doors open for 24 -48 hours to enable the ice to melt.
Should start up OK but you may have to look to see if the defrost element and sensors are OK if it happened again.
BG

[Continental]

You may have a defrost problem of some sort,it's likely the circulation fan catching on a build up of ice behind the back panel in the freezer.
You could unload and switch off and leave with doors open for 24 -48 hours to enable the ice to melt.
Should start up OK but you may have to look to see if the defrost element and sensors are OK if it happened again.
BG

Thanks. Will try that.

Are compressors meant to get that hot though?

[spimps]

The compressor will likely have been running constantly, they will normally reach temps of 55c plus but could go slightly higher if running constantly.
They are fitteed with an overheat cut out.