So it's happened a few times already where I let the car warm up in the morning, when warm enough i leave for work in a calm manner. After about 2 blocks of driving at about 35-40mph, the car will begin to overheat. I'd pulled over, let the car cool, checked water, oil, and whatever I could check with the little sunlight and time I had. After it cooled, I drove off and it didn't overheat again. This happened two times before I realized that the heater didn't blow hot air in the mornings unless I floored the pedal, driving the speed and RPMs up which seemed to cause a valve or vent to open (based from what I could hear). Almost immediately after hearing that noise hot air would blast through the vents and the car was guaranteed to not overheat. The car is a 2004 Nissan Cube 3 from Japan, if that helps (wasn't a selecting option).
My car has 80000 miles.
My car has an automatic transmission.
Hi there - your symptoms may describe more than one problem. A weak water pump could cause inadequate water circulation that is causing both overheating, and poor heater function. The engine overheat, but not heat until you rev the engine could be a combination of a sticking thermostat (sticking close to shut), and a sticking heater control valve (close to sticking shut also, and limiting the flow of hot water through the heater core. I recommend an overheating inspection and a heater inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.
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