Cracked head or leaking gasket. The suction is created on the downward stroke of piston during intake stroke.
maybe my radiator is defective
Running it while leaking can cause it to overheat repeatedly, which can cause thermostat damage , along with other problems.
There are 2 fans that would be running while you are driving and that is normal... the compressor fan if you have the air conditioner running and the radiator fan runs to help keep the radiator cool while the engine is on.
Yes, that is good. FYI, if you continue to unplug things while the engine is running you may cause the check engine light to come on.
directly in the radiator while the van is running
over heat
first turn on the car and add the water to the radiator while the engine is running-- this allows the water pump to work and force the water to all the thirsty parts this will help the radiator and the crankcase fill much faster
If the water is circulating, simply fill the radiator while the car is running. If there is an air blockage, a heate hose that loops up, you can install a T fitting in it that will allow the air to escape. Usually running the car while filling will do it.
A bad compressor belt can cause a whistling noise while running the air conditioner. A bad engine can also cause this noise.
Drain radiator, rinse with water or radiator cleaner, then refill. Don't forget to check the leve after running the engine a while.
It is best to do it while your vehicle is running so it will circulate through the system. You should add it to the reserve tank, never open the cap on your radiator (if it has one) while the system is hot.
The engine running will cause air to come out of a running engine. The Internal combustion engine sucks in air, mixes it with fuel, ignites it, and then blows the resulting gasses out. Also the fan in front of the radiator moves alot of air. So unless you are coasting down a hill with the engine off, it's supposed to be blowing air while you are driving.