A/C makes sloshing water noise

[eric95q45]

Hi,I own a 1995 q45 with 102,000 miles. The A/c makes a sloshing water sound when it's first turned on in the morning. After work, the sound is gone. The sound only occurs with the a/c on. Is this a case of a low refrigerant charge? What service should I perform on this 10 year old system to maintait it? Compressor oil change? Replace dryer? What kind of costs am I looking At? Thanks, Eric

[Q451990]

How do you know it's the A/C?

I'd go in two directions with this... make sure the drain line from the evaporator case is draining properly and make sure there's no air in your radiator coolant. Air bubbles in your coolant will cause a "gurgle" from behind the dash when they flow through the heater core.

If the A/C evaporator case isn't draining properly, it will fill up with water and can cause noises as well. If you don't have a puddle of water on your garage floor a few minutes after parking when the A/C was on, it's clogged. You can use compressed air or a flexible object to clean it out. Just be gentle. I had to replace an evaporator on my truck because someone apparently used a long screwdriver to clean out the drain and poked a hole into the aluminum evaporator.

A low refrigerant charge shouldn't cause the noises you describe - only poor performance.

Good luck!

Heath

[eric95q45]

Well I took your advice and looked for a clogged drain valve. That wasn't it. Then I checked the colant level. It was low. I guess it was swooshing as it filled the heater core. I topped it up with about a pint of coolant and drove to work the next day, (today). As soon as I got home I checked the level again, low again. I searched the valley for leakes, none. Checked the radiator, no leakes. Looked around the throttle body, dry and clean. Checked both radiator type caps, no wetness or residue. What next?

Temp gauge never went above three o'clock. The auxilliary fan did run the first day, now it's quiet. Engine runs fine. The system doesn't seem to pressure up the hoses. Is this proof of a leak somewhere? Or just low coolant?

Please help!

[elwesso]

In LA you dont use the heater much (if at all).. I bet the heater core hasnt been opened much, so coolant will be able to work its way out... I would turn the heater on all the way sometime (probbaly when its really cold out, or when you are not in the car) and let the car run for a little while... A minute or 2 would be sufficient... All this will do will allow the air to escape the heater core. If there are no visible leaks, I am sure this is what the problem is...

Before you go to work or before you leave for home (engine cold, sat for mroe than 4 hours) open the radiator cap and check the fluid level. if its that low then thats the case... The coolant resovoir will only top off an already full system!!

[qship96]

I am under the impression the q heater core is always circulating coolant through it,just the air mix door opens and closes depending on demand for temp change?

[Chally]

No, there is a heater tap. If you read the Workshop Manual, it tells you how to get the tap wide open, but I can't recall it just now.

[Q451990]

There's some debate on this, but I think it's wide open all the time. The HVAC trick that sets the heat wide open is just to pull as much air across the core as possible - I think.

Check your water pump for the leak... there's a "weep hole" on the bottom that will let the coolant drain out when the seals go bad...

Heath

[maxnix]

If you read the Workshop Manual, it tells you how to get the tap wide open, but I can't recall it just now.

From the archives, but haven't tried it personally:

Heater Core Code:

Turn ignition on, press HVAC off button within 10 sec and hold for 5 sec, press hot 3 times, press defrost 2 times, display should read 43, wait 10 sec before turning ignition off. Good luck!

[DAEDALUS]

It appears that procedure would move the air mix door to full hot. I see nothing in the wiring diagrams, exploded views or system description that would suggest a flow control to the heater core. However, in one of the troubleshooting matrices, there is an odd reference to a "water c*** solenoid" but this does not show up anywhere else that I can find.

[eric95q45]

I have an update on the noise. Turns out that the radiator had a small leak on the bottom, passenger side. it was so small it never ran off the bottom cover and onto the street. it was low so the drops never hit anything hot. A new radiator is on the way from Joe, ($398).

[Chally]

It appears that procedure would move the air mix door to full hot. I see nothing in the wiring diagrams, exploded views or system description that would suggest a flow control to the heater core. However, in one of the troubleshooting matrices, there is an odd reference to a "water c*** solenoid" but this does not show up anywhere else that I can find.

Yeah, you seem to be right. The closest thing I got to a tap is on page HA-95 in my manual, which shows a drawing like a tap, but I can't see any mention elsewhere.

[elwesso]

Then I ask

In the MA section, when it says changing engine coolant, why does it say that you need to do the heater core thing.. This would "open" the heater core to allow it to flush..... If it was just a mix door there would be no such thing in the FSM....

[Chally]

Aha, thanks elwesso,

I know I read it somewhere before, but I just kept focusing on the HA section.

Page MA-9 step 6 at bottom of page reads " This step is necessary to allow heater c*** to open wide."

[Q451990]

I read that too, but I distinctly remember Q45Tech saying that the only control for the heater core was the door. I'd also be surprised to have never heard of a failure of this type of valve...

Heath

[elwesso]

Ill tell you what, we'll find out... Over thanksgiving, ill take my dash out and we'll just see if there is such a beast..... No mention in HA...