Alfa Romeo Repair: Alfa 156 problem list, alfa 156, variator

Question
Have a 2001 156 1.6 with 80k miles on the clock. The timing belt was done at 48k miles.
Hi. I am having serious problems with my alfa, the cam variator needs to be changed i know, but there is a serious roaring noise between 2000 - 2500 rpm, is this related? it makes the car sound truely awful.
Also am i correct in saying that there is a second variator at the back of the engine, behind injectors 1 and 2, some mechanics call it an oil variator pump, or a variator solinoid, its the cylindar shaped device wit a small pin on the bottom that pushes in the spring. But my question is, an alfa mechanic disabled it because i reported it made noise because it was dirty or something was dirty, so it lasted months and know the noise i have now, - at 2k rpm has taken over, i replaced the device, no good outcome. when u connect it, the severity if the noise worsens. any ideas?

Last question, lately i noticed the car temp gauge in the car was jumping up and down depending on the speed, i thought it was faulty, as there was coolant and oil etc, alfa agreed and said a sensor could be fault. the car rarely goes below the 90 temp mark now and the fan is running constant, there is very little time i spend in traffic. I did some hard driving last nite on a motorway, going aroung 70mph, and the temp gauge went off the scale, pulled in after a while and there was coolent and there was no smell of burning or anything unusual. drove another 10km and temp gauge still the same, car suddenly cut out on motorway when the em light came on, mananged to pull into hard shoulder and opened the engine to find the coolent tank empty and the smell of something burning. opened the coolent resevoir and steam gushed out for a good couple of mins, it swelled the coolent resevoir. just left the battery on and the fan blowing for about 15 mins until the car started up again, managed to drive it very slowly another 5km home. engine was not sounding to healthy. can u help with that one please?

Thanks, and sorry for writing a bit too much,
your the best,
Joe Foley

Answer
The first clue that the coolant is low is that the in cab heater is cool.  When checking coolant level the overflow bottle is not an indicator. You must remove the pressure cap to check the true coolant level.  It is probable that the erratic guage was due to a dropping coolant level.  You surely have overheat damage at this time.  Previously, the noises were undoubtedly related to the cam variator. (I hate variable cam timing, it is only for a few degrees and done to elimanate the egr valve whick only works at cruise anyway). And, yes, the bits and pieces for the variator needed to be accurately checked out.