Heater

[94 formula]

My heater is barely putting out any heat at all. I looked at the heater core and it looks fine no bent fins or anything like that. Any suggestions on what else it might be. I was thinking it might be clogged.

[N20LT4Bird]

Is the blower not blowing hard or is the heat simply not warm?

[94 formula]

The air is just not warm.

[Injuneer]

First.... what temperature thermostat are you running, what are your fan on/off temps set at? What kind of temperatures are you seeing on the dash coolant temp gauge when the engine is at full operating temp?

Next..... when you move the heating/air conditioning controls, does the system respond properly by moving the air flow to the correct position.... floor and or dash? A problem with the vacuum supply to the controls is common. I would rule that out first.

Finally..... when you mention looking at the heater core... how did you do that? It is buried under the dash in a box? What you really need to do is insure the interior of the core piping is not clogged with sludge.... again a very common problem with an almost 10-year old car, if the cooling system has not been meticulously maintained. The best thing to do is try and flush the heater core, by removing the hoses at the radiator end and forcing water through the system with a hose.

[Bry]

Last week my heater stopped putting out heat on my '94 Camaro. I put about 2 cups of water where the engine coolant goes and about 3 blocks later the heat kicked back on. Took it into the dealer to have it checked and it turns out I had a leaking water pump, among other things.

[00 Ragtop Z]

hear any hissing formt eh dash control unit?? if yes, you havea vacuum leak that is preventing teh unit form controlling the heat. Just had the control unit repalced on my 92 RS for this reason. Heater works fine now.

[94 formula]

I know what the heater core looks like cause I had a vaccum leak before and got in there to check all the hoses to see what if they were leaking anywhere in there. It turned out to be the 3 way valve by the CPC had cracked. When I turn it to heat it makes the air a little bit hotter but barley so I'm thinking clogged heater core too. My cars fans are just on the stock setting and my car runs anywhere from 220 degrees to 180 just depends if i'm sitting in traffic or out on the highway.

[Joe K. 99 Zeee!!]

When was the last time you flushed and filled your coolent? If you don't do it at least every 65k or so the leak stopper in the coolent begins to coagulate and will start to clog up your system.

If this is the case I'd suggest reverse flushing the heater core. I did and got some gunk out. Also you may be in danger of losing your low coolent sensor. This is fairly common in people that don't change the coolent as per the manual. I was one and found out the hard way.

[94 formula]

How do I do reverse flushing?

[N20LT4Bird]

Originally posted by Joe K. 96 Zeee!!
If you don't do it at least every 65k or so the leak stopper in the coolent begins to coagulate and will start to clog up your system.

Leak stopper???? Explain.

[Joe K. 99 Zeee!!]

Originally posted by 94 formula
How do I do reverse flushing?

I took my car to a shop to have this done. Basicaly they took out the heater core and flushed it out with a solution in a direction reverse to the normal flow. There was some gunk that came out. It was barely working before and now it's like an inferno.

[Joe K. 99 Zeee!!]

Originally posted by N20LT4Bird
Leak stopper???? Explain.

You can probably find similar stuff in an auto store. It's designed to stop coolent leaks. I'm no expert on the stuff, but it's supposed to coagulate around those small pinhole leaks. The couple of shops I've talked to add it in after they flush the system. It seems the stuff only lasts so long and begins to solidify after a certain period of time....I think that's why we see so many people losing coolent sensors or heater cores.

[94 formula]

What type of coolant should I use?