Tasha & Mike

>>Put it on a ramp and let it warm up to 'operating' temp with the rad cap OFF. rev it a few times, make sure the heater is on max, refill raditaor with coolant, confirm o'flow bottle has proper to slightly above max coolant level. Allow car to cool completely. Drive and check o'flow bottle for several drive cycles. I tried that. That's what I was referring to when I said I "burped" the car - trying to work all the air out of the coolant lines. I appreciate the advice everybody's given. I'll let you of any new developments.

Been reading for a while, but this is my first post. One of the main reasons I started reading this forum was to try and diagnose the rushing water sound behind the instrument panel of our ‘99 OB wagon. Without hearing it, a local dealership service guy thought it was probably air in the system. People on this board experiencing similar symptoms seemed to also be getting similar advice. It was about time to change the coolant anyway and I'm no stranger to DIY car repair. To be on the safe side, I found some very thorough advice on this board and followed those directions precisely - nose elevated, squeezed hoses, etc. After topping off the system the next morning, we set out on the first errand of the day and there was the noise, as prominent as ever. It sounds like about a quart of rushing water and it’s centered on the firewall (or maybe slightly to the right) underneath the dash. It only happens on initial acceleration when the car is cold, and the sound is gone by the time I shift into third. From the diagrams in my Haynes manual (nominally covering ‘90 to ‘98, but how different can the ‘99 be?) it seems fairly obvious that the heater core is involved somehow. Cabin heat works fine, nothing appears to be leaking anywhere, no coolant loss, temperature gauge where it always has been. The car has about 82K miles on it. Ideas (other than burping the system, which didn’t help)? Mike