Beretta.net

Okay here is my problem.  Recently my engine has begun to run a lot hotter than it used to.  It heats up to 3/4 temp. in the first five minutes of normal driving.  I replaced the thermostat and even took it to a mechanic who ran a pressure and electrical test and still nothing.  He said it was running properly.  
Now just this week it has started knocking when I am stopped and pressing on the brakes.  It's only when the car has heated up though.  Any thoughts on the knock or the quick heat up?  
Thanks.  Hopefully someone can help because I love my Beretta and want to keep her around for a while longer.

what motor is it?

Better to know the motor, but in general that is a pretty warm engine and fast warm up.  With overheating you can get a knock, especially on an old engine if there are deposits on the chambers heating up.  Check the coolant flow to see if it is restricted and causing excessive heat.  The knock is possibly just one cylinder so it goes away when revved or not under load because the other cylinders drown it out.

The engine is a 3.1 L V6.  I'm pretty sure they checked the radiator flow when I took it in but just in case how would I check that?  Thanks for the help.

is it a 3100(94 and newer)? If it is, has the intake manifold gaskets ever been replaced?

if you think something is plugged just get it flushed should be just over a hundred