I consistently hear a swishing sound in my dashboard as if coolant is draining. No water leaks exist within the cabin. Coolant levels remain normal, temperature gauge reads no higher than midway and the van operates as normal. Just this weird gurgling sound no matter what the weather condition, hot or cold, wet or not. ANy ideas?
Sounds like you have air entrapped in your heater core.
If the heat and A/C function properly, is there anything serious to be concerned with or should I get the coolant system flushed immediately?
No, you don’t need to have it flushed. You just need to eliminate the air pocket. Some vehicles have a bleeder for this purpose. Others don’t. Air in the cooling system is not good. Air doesn’t cool the engine like coolant does. You need to make sure there is no air in there.
Are you checking your coolant level at the reservoir or in the radiator?
Thanks TSM and McP…
I placed the front of the van on ramps and removed the radiator cap and let the engine warm up enough for the coolant to circulate. The radiator’s coolant looked clean (i.e. green and without residue), the reservoir had enough coolant, and the coolant hose warmed up as well (indicating proper flow).
Then I replaced the radiator cap and took it off the ramp and for a spin around the block (corners, hiils, etc) and the swishing sound is now gone.
Fingers are crossed…
Cheers,
RP
Cool. The angle it was on on the ramps may have been just enough to allow the entrapped air pocket to escape through the system.
Happy otoring.
Good going! One more item: in cars that have a valve to control the amount of coolant that flows through the heater core, it’s a good idea to have the heater set to Hot when draining, filling, or burping the cooling system.
Some cars have full flow through the core at all times, and control heat to the cabin with flaps in the air ducts. Then the above does not apply.
I’ll keep the that in mind Shanonia, especially as I don’t want this to occur again. Digging through my Chilton manual this morning I didn’t come across much in regards to the heater core, other than replacement. Suffice to say I hope this doesn’t reoccur, otherwise I’ll be visiting the neighbor mechanic. 
Cheers,
RP