When I accelerate, I hear water running under the dash. It doesn't do this after running for 20 minutes. Is this thermostat problem?? or the heater core??
is hoses switch crossed?? any idea??

When I accelerate, I hear water running under the dash. It doesn't do this after running for 20 minutes. Is this thermostat problem?? or the heater core??
is hoses switch crossed?? any idea??

I've had that problem before. Here's what had happened from start to finish. At first I thought I had a radiator leak from inside, but it was a faulty cap. So I put in some StopLeak, and it kinda gunks up your system, and makes it sluggish in accepting any new fluid. I kept filling my coolant tank (with 50/50, not StopLeak, haha), and it kept going down about an inch every other day. Then after a while it stopped, as well as stopped making the swishing water sound under the dash. My Jeep had then returned from a boat back to a car (because every time I'd step on the gas (in park) it would make that sound)

I'd try flushing the radiator if nothing else is working for ya. That's the only thing I can think of that would help.

Well I had this same thing in my 94, swishing sound of water when I would rev the engine. I also had a heating problem, turn the heater on and it would be hot for a few seconds then cool down to a cool/luke warm tempature (altho the temp control was on HI) - This was all due to a clogged/partially clogged HEATER CORE, I flushed and reverse flushed the heater core along with flushing the entire cooling system (including engine block) and all has been good since, good heat and no more swishing noise.

I had some great tips about how to flush the heater core using some washing machine hoses on here, I will find the thread and post it.