Heat issues

[BrianSZ]

Hello, I have a 94 camaro 3.4l and the other day the engine started to get hot. It is like 20 degrees up here so I didn't really get it, I tried putting on the heat but all of a sudden its blowing cold air? If the engine is hot wouldn't it blow hot air? By hot i mean the enging is in between the 3/4 mark and the orange dashes. Can anyone help me out with this, Thanks

[NoRiceInside]

well first thing, check the front of your radiator above your airdam. when i got my car there were two plastic bags stuck in there and that will block airflow. second, check the coolant. it might be low or the improper mixture. its supposed to be 50% water and 50% coolant. it might be a good idea to flush the system out.

[My3birds]

check if any of your hoses are leaking, and if its not that, you might have a bad water pump gasket, thats exactly what happened to me recently

[dafirebird]

Maybe the thermostat is stuck closed. In that case, the engine temp. would rise, but not allow coolant to flow through the heater core for interior heat. Just a thought.......

[BrianSZ]

OK, i tried adding 300ml of coolant 50% water to see if that helped anything, but today on the way home its like 10 degrees outside and the heat gauge get to 260+ on the red lines and check gages light comes on, also not only is the heat cold it is also not powerful at all, before there problems occured it shot out heat very powerful now its barely coming out. Thanks

[BrianSZ]

Also dont know if its related but lately car turns for a few seconds before starting, guess my car just hates the cold.

[BrianSZ]

Let me update, I added a bunch more coolant, and for about a week it was running perfect. Now just today it appears there is enought coolant, but problem came back, any ideas?

[V8 Killer]

Keep adding coolant...Get the entire system checked out.

[LwnGy83]

First off... check all your coolant lines and places where coolant could be leaking. On my 94 3.4L I had a very similar issue and it turned out that the timing chain cover gasket blew, which leaked coolant, and it's very very hard to see. But I would first, flush the system thoroughly, then replace the thermostat and get the proper amount of coolant in there. If that doesn't fix it, you have a leak, and you better pray it isn't the timing chain cover, but that was a PITA to replace. You'll have to take pretty much the front half of the engine off to get to it. So, try a good system flush and a new thermo and see if that doesn't help. Good luck.

[BrianSZ]

So today I flushed the whole cooling system, didn't fix the problem so I started looking around and it appears that my radiator fan is malfunctioning.. it never turns on. I could see this causing the overheating but I don't see how this would affect the heat problem? According to my Haynes repair manual if the upper radiator hose is hot then the thermostat is not stuck closed, and it is in fact hot. So the fan?

[oil pan 4]

If it heats up real fast than it is not just the fan.
The thermostat could be stuck closed but it could be cracked, opened just a little bit.
When you drive down the road can air hit your raidator?
Or is air flow blocked like on a fire bird?

[BrianSZ]

I think airflow can hit the radiator, thats why it seems like it should only get really hot at idle whether fan is working or not. Guess I will check the thermometer tommorow, even tho it seems like those two bolts are gonna be a ***** to get out.

[Christian]

Originally posted by BrianSZ:
I think airflow can hit the radiator, thats why it seems like it should only get really hot at idle whether fan is working or not. Guess I will check the thermometer tommorow, even tho it seems like those two bolts are gonna be a ***** to get out.

Update? I'm having the same issue, brand new radiator (less than 2k on it)new H20 pump also......

[HBHRacing]

if your engine is reading normal temps and there is no heat coing from the vents you either have a blocked heater core or a problem with the blend door. I would have to guess it's the first.

Maybe the thermostat is stuck closed. In that case, the engine temp. would rise, but not allow coolant to flow through the heater core for interior heat. Just a thought.......

Thats not true. The water pump bypasses the coolant when teh thermo is closed. It will curculate in bypass mode to teh heater core. this is one for the exact reason of getting heat inside before the thermostat even opens.


But if you have been adding collant I sugest that you also look for a leak. It's not going to really have anything to do with the inside not getting warm but it's still something that you want to take care of.

[arthansen]

Low coolant level will cause the heater to not work properly. I have seen this in many cars and trucks. The heater is above the engine so air in the system will rise and fill the void left by the lack of coolant. It sounds like you have a leak. Have the system pressure tested. Once it is fixed, follow the filling procedure to make sure the system is filled properly (not just a matter of putting coolant in the system, follow the procedure).