Noticed engine temp was rising. after stopping, checked coolant reservoir. had to add to top off line. next morning, before even starting engine, noticed coolant was back down to almost nothing. filled again (only drove 6 miles the night before).
there are no leaks on the floor of the garage; nothing spits out when hood is up and engine running; did a pressure test on radiator, resulting in tester showing radiator didn’t hold pressure; hose from radiator to engine was soft when engine running, but could be tightened up to “hand pump” coolant into engine while engine running;
ALSO fan only runs intermittently, not all the time after 3.5 mins of not running.
comments?
I think you need to do an (engine) coolant pressure test, you MAY have a leaking head or intake manifold gasket.
I would run the car on the highway till hot, pull over and shut off the engine. Lift the hood. The cooling system pressure will rise with the engine shut off and an exterior leak will likely show itself. Look everywhere, including under the car, and inside the car for a possible heater core leak. If there is no external leak, you will likely have an internal leak (head gasket?), which will reveal itself most likely as white smoke out of the exhaust. The coolant has to go somewhere!. Agree that a cooling system pressure test is necessary. A third possiblity is the coolant somehow finding its way into the transmission through a leaking transmission cooler in the bottom of the radiator. However, your transmission would be ruined by now with all that coolant in it.