replied 8 years ago.
Hi there, flushing the radiator is definately a great idea and spot on, by the sounds of things this may possibly be blocked, but may i also suggest reverse flushing the engine block, do you know the last time that this was done, or the coolant replaced, the reason why i say this, is if you flush your radiator and your engine block is full of corrosion then your hard work will be to no avail, if i could suggest perhaps ,using a cooling flush additive to do this, pour it in and let it run in your motor for approxiamately 1 Hour or so with the engine running, make sure you have your heater in the cabin switched to hot (all the way).
Upon doing this then proceed to drain the coolant, by detaching your lower radator hose and/or also look for a drain tap in the botttom of your radiator- do this with the engine is off, and cooled down, and have a massive container to catch the coolant.
Once drained, with the engine cooled, totally, remove your thermostat and run a hose into the motor, (make sure the engine is off), and under light to mild water pressure, flush out the engine block- you may wish to detach both radiator hoses at this time. If you find rusty water coming out flush unil its all clear and clean, then do the same to the radiator- flush also until clean and clear.
Upon doing all this reinstall the thermostat, ( if the thermostat has a small hole in the steel surrounding ring, make sure its positioned at the top, this helps to bleed the motor of any air pockets in the coolant-failure to do this can cause over heating, but it may not have a small hole-if not dont worry, just install.)
Then re-install your radiator hoses, ensuring they are secure/tight, and fill engine with coolant concentrate, dont use premixed,as this is merely coloured water, and not as effective as a concentrate, being a v6 you will need approx 3-4 litres, of concentrate, then fill the rest with water.
once filled run the motor with the radiator cap off until warm, on the temp guage, stand by with a container of water to top up when needed, also make sure your heater switch in the cabin is still switched to hot, run the motor until the engine is warm on the guage or you hear thermo fans cut in- if your model is equipped with these.
This process may take a while, so you can idle the motor steady at 1200rpm (holding- dont free rev) and this will speed up warm up times, then once warmedon the guage, or thermo fans cut in relax the idle and top up if needed and then reinstall the radiator cap.
Road test down the street,for a couple of miles perhaps 3-4 just to make sure all is ok. If you find upon reading this that your not confident in doing this, thats ok, you can speak to your local radiator specialist or your mechanic, or Dodge service dept and they can do this for you, ask them to reverse flush the motor and the radiator, and renew the coolant.
If this problem still persists, you may have to have your radiator cores inspected, for hard -core blockage, by a radiator specialist,-(large peices of grit, lodged inside the cooling fins stopping water flow).
If you have any further questions please dont hesitate to ask!!
Best Wishes; Matthew (aka;Matt0302)