My 2014 RDX 2WD 6-cylinder has started getting hot while vehicle is stuck in traffic or when stopped with engine running. It's gotten hot enough once to trigger an engine temp warning code before traffic started moving again. Temps are normal when moving. Coolant level is normal. Fans run when engine is shut off. Haven't verified if they come on when running.

Any suggestions on what to check first?

 

How many miles do you have on your car? Make sure to check if the radiator and if all the hoses are getting warm. Maybe your thermostat is getting stuck open. I would check the basics and see where it leads you too...

 

Might need to flush the cooling system. I have experienced problems over the years from rad's calcifying and loosing capacity to keep the engine cool at time, just as you have mentioned. If there are a lot of miles on the ride, yo might need a new rad
and maybe even a new water pump.

 

both posters are pretty much on the right track!

good job fellas

 

I'd check the radiator first by uninstalling it and running a hose through it, water should come out the other end. if blocked, perhaps the pressure of the water hose might dislodge whatever is stuck in the radiator.
then, since you have already disconnected the radiator hoses, you would have lost some coolant, I would flush or drain all coolant and pour new coolant in.

if everything thus far has checked out, and it's still overheating, i'd check the waterpump and possibly replace.

 

Agree with all the above , and will add,,make sure the electric cooling fan is coming on as it should,,If that fan isn't working properly , your car will heat in traffic and not out on the road.