Engine system fault and black smoke!! Disco 3 2009

Hi new to this forum as recently bought a 2009 disco 3 4 months ago. All good for 3 months then I started to hear a quiet 'screeching ' like sound when I was slowing down without brakes using gears. After few weeks suddenly engine system fault warning came on and smoking like mad!! No screeching sound now (you could hardly hear it anyway) but engine system fault comes on now and again then she smokes heavily. When fault not showing she still smokes but not as bad. Until all this happened you could boot the hell out of her and no smoke whatsoever. My fitter away on holidays and it's due in next week but wondered if anybody had any pointers for me to tell him as I know sometimes these sorts of things trial and error and my wallet doesn't appreciate that!! Thanks all any more info needed let me know but I'm no machanic!!

Could be a multitude of things, you need to get it scanned first as a fault like that should have recorded a fault code. You could check the basics first water / oil levels etc to see if anything has dropped low.

Most likely one of the egr valves faulty , unless it's a simple split hose

thanks guys, went in the other day and it was the intercooler, seem split it was hard to see. changed and all running spot on