Cooling/Heating Issue
 

hey guys i have a question, when my car is fully heated up in the morning, the temp gauge acts weird. First off when i am driving he gauge goes down to normal operating temperature, and when i am at a red light or stop for a period of time the gauge goes up, past the half way point. Also the heat goes in and out one moment i am getting hot air and then the next i am getting cool or cold air when the setting is on max hot. I only turn the blower fan on the second or third level too. What i did in order to see if this fixes the problem is put more coolant into the system. hopefully this works, but what does this mean what could be going wrong?

Just off the top of my head, the thermostat maybe?

^Could very well be. Or maybe air in the lines?

As Taz said, consider checking your thermostat.
The interior air going hot then cold and hot is a sign of an air pocket. Was any service to the cooling system recently done? If so, you may still need to bleed air out.

If not, check for leaks (signs of coolant under the car after parking it for a while, anything under the car that's wet with coolant).

Those are your first starting points... And hopefully the problem is easily found.

Only thing I do is add some coolant (dexcool) from time to time, sometimes I find coolant on the back of the exaust. Under the throttle body. I'm gonna try n bleed system, I think I jus need a flattip if I remember correctly?

it's a good chance that it's your water pump. had it happen on my '03, twice. both times the pumps blades had rusted completely off.
the good news is that it's easy to replace them and very inexpensive.
if the car is anywhere near 100k, you should replace it to eliminate that from the equation.

Based on what you just said, you have a coolant leak. You are loosing coolant, getting an air pocket and that's what's causing this.
Best thing to do, get a radiator pressure tester from a auto parts store loan a tool. With the car off and cold, hook it up, pump it to about 13lbs, inspect for hissing sounds and bubbling.

I'm not sure what you mean by "back of the exhaust". But under the throttle body leaves:
- Bad throttle body gasket (if it's dripping from the throttle body, that is probably it).
- Failed UIM gasket
- Failed LIM gasket
- Failed UIM
- Failed t-stat gasket (honestly have not heard of that, but it's possible).

First part is narrowing where the leak is. Any pics of what you see can also help.

i'll try and get some pics tomorrow when im on break hopefully you can see the area where im talking about if not then i'll edit it so i can show the area i mean

im runing on 93500+ right now i dont think its the water pump its not leaking on that side, not a bad 100k tune up job tho

http://i45.tinypic.com/29n6jyq.jpg


http://i46.tinypic.com/5ufmtx.jpg

If you see the pic with the dexcool thats where it drops down at. The coolant resevior is either low or always empty. So could this be reason why my heat goes in and out?