I have been having a little heating probs lately as well.. I replaced my stat and still have it... another culprit could be the fan clutch...

I am still working on my situation... the only things I havnt replaced is the rad. and water pump

 

The T'stat is an easy job, but be sure to test ALL new t'stats before install. Many are defective and many just plain are crap, no matter what brand.

 

"Back to straight-up temp!!"

"If you can STOP your cooling fan with a T.V. Guild, then you probably need a new fan clutch. I had a BIG TIME overheating problem and a $42 fan clutch from Smoto-Zone got my temperature BACK ON THE STRAIGHT UP!!!

 

A cool radiator and a hot engine means low or no water flow.

Could be a water pump or a T-stat. Since you radiator is new it is most likey OK.

Try testing the T-stat by removing it then see if the radiator gets hot as the engine temp increases. Then if there is no change from your current condition then go for the water pump.

Don't run your engine without a t-stat. Remove it just for short term for a system test.

 

go for the Nissan tstat. I've had nothing but problems with aftermarket ones in the past.