Whooshing Liquid


I hear whoooshing liquid just the other side of the firewall about were the heator core is. This has happened twice, the 1st time about two years ago, and 2nd time currently.

The first time I added some coolent mix to the radiator overflow tank and the swooshing stopped. Adding coolent the 2nd time did not work.

The cycle; start a cold engine; put in gear; accelarate; whoooshing; reach speed limit; whooshing stops; stop for red light and the cycle starts again till, I believe, the thermostat opens. Then the engine has to be cold before this cycle starts again.

Do I need to Clean the radiator overflow tank and hose or change the radiator cap?

The car is a 94 Mercury Sable 4 Dr. with larger engine. 134K miles. There are no noticable coolent leeks. Thanks


The bad news is that the 3.8 was prone to headgasket failure. This could account for the symptoms you’re having. Take a look at the oil on the dipstick. If it looks like a coffee milkshake, your engine is in serious trouble.

If the oil is normal, try changing the radiator cap. A faulty one can certainly let air into the system.


What NYBo said. That’s step #1. Somehow, air is getting into the heater core. When the engine heats up, it is somehow pressurizing the system enough to displace the air. Hot expands-cold retracts. 134K miles? Betcha it’s the radiator cap. Ensure that you get one as per manufacturer’s specifications for pressure relief ratings, like 12-15 p.s.i. or whatever the manufacturer says. Are you noticing an above-normal amount of coolant mix in the recovery bottle? Change out the cap and let us know of any different results.


I will check the oil to night. I had the oil changed about three weeks ago. No news from the repair person. How do you remove the air from the system once you replace the radiator cap? What about having the system flushed? Also the coolent in the recovery bottle looks the same as when I put it in. Could the cap not be seated correctly?


A nick in the rubber gasket or a weak spring can cause air to enter through the cap.


I checked the oil. It did not have the coloration you spoke off. It was still fresh looking. Thanks