Running water sound

[Malibuskier]

I have an 89 C1500 and it is making a strange noise. When I accelerate, I hear water rushing through the heater core. It rushes for about 10 seconds then stops. It does it often. Any ideas as to what is causing this?

Dave

[SageCuda]

That can happen when you don't have your radiator quite full, and you get air bubbles. Fill it up with antifreeze/water mixed and it will stop.

[broughy84]

there is a restricter in the heater hose that can cause this. It is not a big deal just a minor inconvienience...both of mine do it but it doesn't bother me enough to jack with it.