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Sloshing Sound-Heater Core?

08-27-2004, 08:10 PM

I've been mentioning about a sloshing sound in the front of my car when i accelerate from a stop. I took it in and the dealership said they checked all the drains and none were blocked, but that the heater core could be the problem. The heat does work but he said that when heater cores get older they sometimes hold water like that. Should i believe the dealership mechanic? Have any of you heard of this? If so if i were to leave the water would it damage my car via rusting and mold?

08-28-2004, 07:18 AM
I've never heard of what he's saying. TEh heater core is a series of tubes fed by water under pressure. It is virtually impossible for water to get trapped in a heater core surrounded by air to create a sloshing sound. Teh water and air would be forced out under pressure, so I doubt that's your problem. The only suggestion I have is to find out what exact drains they checked, be sure they checked your cowl drain, and not just the one for the heater box and A/C evap core. The only other place water could be is in the floorboard under the carpet, have you noticed a musty smell in your car? Take the bottom door sill plate off and look under the carpet, there are places water can set that won't necessarily get the carpet wet, but I don't think they could create the sloshing sound you described in your earlier post.

08-28-2004, 10:52 AM
I don't know if the cowl would be the problem because its been raining constantly the past week, like monsoon like and i havent seen any leaking in on the interior.

08-29-2004, 03:11 AM
I heard the same noise. Two weeks later my intake manifold gasket went bad and my engine overheated. Check your coolant levels, and consider checking out those gaskets BEFORE they blow.

08-29-2004, 01:26 PM
When i bought the car the coolant was old so i had them flush it. Im pretty sure i heard the noise before they flushed it. When they redid the coolant they said they noticed the thermostat or something was bad and wasnt working. My car doesnt overheat right now or get anywhere above half way temp wise. What should i do? Where is the water and why is it there? Is there any simple way to get rid of it? Cost?

08-29-2004, 10:35 PM
If i leave the water where it is, will it for sure cause rust and kill my car from the inside out?

08-30-2004, 09:54 AM
The only other thing I can think of is is you have a cracked upper intake plenum, and the water is inside the upper intake, but I wouldn't think that would make a sloshing sound in the car. Do you lose coolant? If you're slowly losing coolant, I would say to have your upper plenum checked for cracks where the throttle body mounts to it. If you're not losing coolant, you have me stumped.

GTP Jeff
08-30-2004, 01:29 PM
I'm betting that it's the evaporator drain that's clogged..It's not your heater core, or you'd smell the anti-freeze.. Sometimes, just "checking" them won't see the problem.. You need to blow back thru it with some low pressure compressed air..

08-30-2004, 06:28 PM
when i run the air conditioner i can see water dripping out of the bottom of my car

08-30-2004, 08:56 PM
I had a leak in my "heater bypass coolant pipe". The water leaking out of that sounded like a sloshing. Nobody can pinpoint your problem online. You need to leak check your entire cooling system.

08-30-2004, 09:53 PM
wow, a mechanic is going to have his way with me because i know very little when it comes to things under the hood of a car...

09-30-2004, 07:34 PM
I may be late to the party but I have a similar problem. I listened to the sloshing for several weeks before I notices the floor in the drivers side was wet.

A couple of weeks later my low coolant light came on. I just ordered a heater core.

That said, I replenished the coolant and my floor has dried up. I'm a bit baffled by the whole thing but I still plan on replacing the heater core this weekend.

09-30-2004, 08:33 PM
Most of the time that leak is either caused by a pluged drain tube or the plastic cowl that needs fixed....when it rains that water goes in the heater box and then drains on the floor board.

Might want to save the reciept for the heater core,since it may not be bad :wink:


09-30-2004, 10:59 PM
how much was the heater core replacement, i heard it as being around 2500 with labor, if i were not to repair it what would happen?

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