Heater Core Flush?

[BlazerLT]

Originally Posted by Phoenix69

This airlock you speak of, is there a good chance i can solve it by the methods you listed? Mechanics tell me that the heater core typically needs to be replaced? Is this usually the case or does a thourough flushing/cleansing take care of it most of the time?

Needs to be replaced when?

[blazee]

Originally Posted by Phoenix69

This airlock you speak of, is there a good chance i can solve it by the methods you listed? Mechanics tell me that the heater core typically needs to be replaced? Is this usually the case or does a thourough flushing/cleansing take care of it most of the time?

Sounds like they are trying to screw you, it should only be replaced if leaking. I haven't seen one yet that couldn't be unclogged. They will probably back flush and tell you they replaced it.

[blazee]

Originally Posted by chcknugget

They might have done the flush incorrectly, but chances are you have airlock. I agree that you shouldn't use "ghetto flushes" to make up for neglecting your cooling system, but if you have maintained your fluids well or even payed a shop to flush and fill, more flushes might not get the air out of there.

Any air in the system will be removed by a properly working rad cap:

As the coolant circulates the air moves to the radiator (the highest point). As the temperature increases the coolant expands, this expansion causes pressure when the pressure reaches 16psi the air pushes past the cap and goes into the overflow which is vented allowing the air to escape. When the system cools back down it draws coolant back in from the overflow. After repeating this process several times all the air will be evacuated from the system.

If the cap is defective instead of drawing coolant in from the overflow it will leak around the cap pulling air back in to the system. That is why a properly working cap is crucial for a healthy system.

[Rick Norwood]

Phoenix69, First, I think you need to give us a few more symptoms of what exactly your problems are.

Second, If you are living in an area known for its hard water (like Phoenix), Radiator corrosion and plugged radiator/heater cores are much higher. If you perform a good thorough clean/flush as described by Blazee and install a new CLOSED LOOP Rad cap you should see improvement. Don't buy the AC Delco Cap! A new cap will force the air out automatically. You can easily verify this in the morning when the engine is cold. Open the rad cap and the observe the coolant level. It should be full to the very top of the radiator.

I would not just run out and drop $200-$300 for a new heater core. This is just a hungry mechanic trying to make a fast buck by screwing you.

Try disconnecting both heater hoses and attaching a garden hose directly to one of the heater core fittings, you might need a hose clamp. Turn the water on full force and see how much water is flowing through your heater core. This will blow any loose crud out of the core and might solve your problem. If you observe limited flow, or if you're having still having problems after the flush, Then it may be time for a new core.

[Phoenix69]

I have read that if you turn it on full force you risk a chance of blowing a line, and also that if you run your engine while running cold water through it you run the risk of warping internal aluminum components from the great difference in temperatures.
Before i bought my car i saw that the coolant was in poor condition and thought that a good flush would fix it. When i did the test drives i didnt notice the sloshing noise. After i brought it home a few days later i noticed the noise. When my dad brought the car back for the flush that the manager had agreed to my car thermostat/thermometer blew out. I'm not sure if that has anything to do with the flushing or if it was just already dead. But anyways the flushing seemed to possibly have made it worse. I talked to another mechanic about the problem and he said that he's seen it several times with all makes of cars and that he flushed a mans system 7 times and it did not solve the problem, and that the system had to be replaced. He said that this may be the case with me, he told me this not looking for work (didn't say come back here or anything, seemed honest).

****The symtoms my car has are as follows:*******

1.) When the heat it turned fully up I get luke warm air from my blower even when the engine is fully warmed up (told that a clean system should almost burn your hand).

2.) Whenever I accelerate or take a turn/accerlate I can hear a sloshing noise, as if alot of water is going through tubes, sounds like a good gallon+ worth of water in front of the dash, perhaps moreso on the passengerside of my car.

I originally thought that the water noise i was hearing was a drain that had become blocked up or possibly a water filled cowl and started to retain rain water. Another thing that made me think this possible was a hole in the weatherstripping around my windshield at the bottom/passenger side. It seemed that after a rain storm the sloshing became louder (perhaps imagination). Mechanics said that they checked and did not find any blockages. I too checked the HAVOC box and other drains and have not found a blockage. All mechanics and other people on forums have directed me towards the conclusion that I have a clogged up heater core. It seems as if my 1997 Grand Prix has never been flushed. The car has 50,000 miles on it if that has any importance.

[Rick Norwood]

O.K. let me clarify. The actual flushing is done with the engine turned OFF. I kinda doubt the part about cold water warping engine components. How cold do you think the water is when you start the car in the morning when it is freezing outside? The worst that would happen is that the engine would probably run rich. However, to the point, make sure the engine is not running when you perform the flush.

If you diconnect BOTH heater hoses and connect a garden hose, you should get some flow through the core, and very little pressure build up. If you don't get any flow through the heater core, it won't matter as the core is plugged solid and probably shot.

Have you replaced the Radiator cap yet?

[chcknugget]

Your core is probably not even clogged if you have been through all those flushes. Airlock in the heatercore is very common. While you car is cold do the heatercore flush that has been outlined.

[BlazerLT]

Sounds like the rad cap is leaking in air.

Replace with anything other than a AC Delco, Stant is the right brand at Autozone.

Also, did they reverse flush the heater core?

[Phoenix69]

I'm not sure if they did reverse flush on my heater core. Can you help me pick of the exact rad cap that i need?

[BlazerLT]

Go to autozone and use their application guide to get the right stat for you.

[blazee]

The Autozone in my area doesn't sell Stant. Around here you have to go to Advance Auto. Autozone doesn't sell them online either.

[Phoenix69]

Would Pepboys have it?

[Rick Norwood]

Probably. Any other brand name except AC Delco will do just fine. I'm running whatever the generic brand name is that Autozone sells. The AC Delco's leak air, that's why you don't want them.

[97blazr2]

i had the problem of cold heat, i flushed my radiator today and its awesome, try that see how it works

[DaveLance]

97blazr2, did you get the radiator or the heater core flushed?