Automotive Forums

I have a 95 Firebird Formula with the LT1, I am having trouble with the heater. Basically I can feel warm air but it is not hot like it used to be nor is it near hot enough to warm up the car. the car does not overheat, but I have noticed the temp. get higher than usual when I am sitting at stop lights. My low coolant light keeps coming on,  I have checked the fluid level in both the radiator and overflow and both are full. I replaced the thermostat and it did not help either. I figure it could be one of the following; A clog in the heater core, a bad heater control valve, or maybe a sensor is bad. If anyone has an answer to this I would greatly appreciate some input?
 

you have some good possibilities already add to that possibly the coolant is not a 50/50 mix. Too much water will overheat the engine. Your coolant/antifreeze should read to minus 10 at least.  

Since this has a 4L60E trans , I take it that this has a belt driven fan right or wrong? If it it is a belt driven fan , A bad fan clutch will cause it to over heat at stop lights.  And your other problem with very little heat leads me toward a pluged heater core. Over the summer I have run into a lot of bad theromstats that people installed on there own, most parts stores sell 2 or 3 different quality thermostates, always buy the best one, only a couple of dollars more.  

It has an electric fan, and the programming in the car makes it kick on about 20 seconds after the car has been started. The thermo I bought was a Duralast from Autozone. Would you recommend using CLR or something like it when back flushing the Heater Core? Or is just plain old water fine?  

I took a breif look at the Autozone website for a 95 firebird 6 clylinder.
I looked under reinstalling a thermostat. It said to bleed the system as the last thing to do.
Some cars because of the way they are constructed today--as opposed to earlier engines-- will trap air pockets in the cooling system and they have bleeder valve/s for this. If you have air trapped in the system it will not flow properly. Have you checked or looked into this??

Have you checked for heat in both the in and out hoses for the heater coil? they are right at the firewall.

Have you followed those hoses back to the engine to see if there is a valve to stop and go water to the heater coil?

I mention these things because #1 you did mention occasional overheating. Which might indicate air in the system.And #2 flushing the heater coil in not an option.
When a heater coil gets plugged up its like a catholic marraige--its forever. The only cure for it is to change it over for a new one. And they can be a Bear to replace. Lots of things have to come off to get to it.  

http://www.autozone.com/az/cds/en_us/0900823d/80/1c/ef/6d/0900823d801cef6d/repairInfoPages.htm  

Apparantly posting a link or url to another website is not allowed,,probably to prevent advertising.
You can go to Autozone website and plug in your car for free repair info. Look under electrical section and they have reinstall advice for the heater core plus pictures.  

I have been planning on getting underneath of it and checking the lines, But I have been busy with work. I think I will have to get on it in the morning. I havent thought about air in the system, actually I never had to bleed the coolant because my thermo. is right under the Throttle Body and was high enough up that it did not leak out much fluid. My car has the 5.7l engine though and there may be a difference on thermo. placement between that and a v6.  

I went to Quicklube for maintenance service for my JEEP Wrangler 2001 and they tell me that after computerservice evaluation, the Jeep needs transmission oil change and other services. I accept and they billed me $168.00 (Aprox) for the service. The day after that service, we were traveling in the Jeep, as all sundays, and after an hour of trip, the Jeep began to loose power and turn off. After a waitin period of a half hour, the Jeep restart and we continue coming back home. In a few minutes the Jeep lost power again and turn off alone again. This repeated until we arrive home. The day after, we went with the Jeep to an authorized car maintenance and repair near home and they check the car and tell us than there is a problem with sensors, joints and oil. He bill us, and we paid, over $700.00 for the service but the Jeep continues with the same problem.
By the way, we hear some noises that does't heard before. What can we do?
Were is the problem? Who is responsable for this problem?
Thanks for you attention and any help.