Previosly, 5-10 mins after start engine hot air go thru ventilation.
But last couple days when start engine, hot air start go thru ventilation after 30-40 mins even temperature lever is in full hot position.
Problem?
Solution?

 

Thermostat stuck open or system needs to be bled. How long does it takes to get up to operating temp?

 

yep try replacing the thermostat, cheapest place to start. probably stuck open as said

 

to operating temp, just usually. aprox 10 mins.

 

Make sure the the (heater) valve on the firewall, in the engine compartment, opens all the way when temperature switch is operated on the inside. The valve has two vacuum hoses that open and close it.
If you have a VG motor, there is a 10mm screw on top of pcv valve for bleeding air from the system. You could try these before getting into the thermostat.

 

does radiator cap maybe a problem?

 

I've been having similar problems on a 97 maxima. I've tried nearly everything else within reason, and now am looking forward to trying the heater control valve. So when testing the heater valve, if i understand you correctly, does it open as soon as the climate control gauge is turned to heat? Is there anything else I need to look for?

 

You need to make sure that the coolant level in the radiator is full and that you have no air pockets in the engine. Check the coolant level in the radiator when the engine is cold. Remove the radiator cap and the radiator should be completely full to the top.