Alright so I just bought a 1996 Z28 that was sitting for a while. I replaced the thermostat after driving home and realized it was overheating, the coolant was spewing out of the reservoir tank. I then flushed out the system and changed the coolant putting dexcool in it.

It still overheats, the fans are running fine, the radiator seems ok, the hoses arent that bad but could be replaced. The only thing that is left is the waterpump. Do you guys think that it can be the water pump or is there something else I am not thinking about?

Also the display on the factory radio was working during the day but now the light is off, what can be causing this? its just the display and also the lights on the shift box

 

did u bleed the air out of the system? check your fuses. could be the bulbs but would be odd if they go at the same time.

 

I know I just ran water through the radiator with the drain plug out and before that I drained it out from the drain line for the engine... How do you bleed the air out?

 

there are bleed valves on the therostat cover, inline on a coolant hose and at the bottom of the tb. i think three on the 96, there a little flathead screw valve. losen screw to bleed. brass screw. bleed it while u fill the system with coolant (50/50 antifreeze/water)start motor with rad cap off and bleed again filling the radiator as needed. if u can park the car on a incline with the front of the car up while i do all of this. after all this drive it a mile down the road and back, and bleed/check for air and fill to top.

 

I see the one the line going to the thermostat, I havent seen the other two, ill try it right now

 

the one at the bottom of the tb is by where the little hose goes in under there on the driver side. the one in line is on the passanger side by the alternator, a heater hose size hose with a alumimun part to it. the bleeder is in this part of the hose. the one on the thermostate cover is the one to do first. im explaning this from my 93 so yours may be a little different.

 

No I found all three... but its too late to do it now ill do it tomorrow after work, it has a rough start, you think it could be from the cooling system or just a regular tune-up will do the trick?

 

ever change the plugs? that can make a big difference if its been a long while. get some good plugs cause u are not going to want to do it for a long time. are u losing water? check oil for water.

 

I highly doubt I have water in my oil... the only thing is the water will boil up and spew out of the reservoir tank as if its not going through the engine. I just hope the tranny is a small problem, it doesnt shift from 2nd to 3rd when it wants it just revs up, no grinding nothing. I dont think its solenoid because wouldnt it have the check engine light if it was

 

CAR RADIO NOT WORKING:

Did you disconnect your battery? I’m guessing you disconnected your battery to work on your car and it shut your radio off. Like Craby said, check all of your fuses.


ENGINE RUNNING HOT:

You should find the links below helpful. The cooling system in the link is from a ’95 LT1 Camaro and I’m not sure if the ’96 is different.

Everything you wanted to know about how to troubleshoot your cooling system:
http://shbox.com/1/4th_gen_tech2.html#cooling

Location of bleed screws on ’95 LT1 Camaro:
http://shbox.com/1/bleeders.jpg

You had asked if your water pump was the problem or if it might be a different part that is causing your system to overheat. In order to determine what is causing the issue, you need to do some tests and have a good understanding of how the system works.

I apologize if I’m about to tell you what you already know, so skip the rest of this paragraph if you feel you have a good understanding of the cooling system. In a nutshell, the thermostat will allow the coolant to exit from the engine and go into the upper radiator hose, into the radiator to cool off, out of the lower radiator hose, and back into the engine before returning to the radiator to get cooled off again. If the engine gets too hot, the PCM will know via the coolant temp sensor and it will turn the fans on to help cool the radiator (via fan relays). The system must remain pressurized by a spring loaded 18 psi radiator cap and cannot have air pockets for the water pump to properly circulate the coolant through the system. If the thermostat does not open properly, then it will not allow enough coolant to go to the radiator. The temperature gauge sender tells the dashboard gauge the proper temperature. One last thing, if there is too much coolant, it will exit via the coolant reservoir.

That being said, here are some items/tests for you to consider.

- Is the water pump working?
After the engine reaches operating temperature and the thermostat is open, put a glove on and squeeze the upper radiator hose shut as best you can. You should wear a glove because the hose should be hot. If you feel a rush of coolant go through the hose after you let go, it is a good sign that the water pump is working. Other tests you can do include checking to see if the water pump is leaking (it may leak through the weep hole) and determining if it is emitting a high pitched squeal (bearing wears out). The drive belt must have proper tension for the water pump to function correctly. This is because the drive belt powers the water pump’s pulley.

- Is the upper radiator hose hot after the engine reaches operating temperature and the thermostat opens?

- Is the lower radiator hose cold after the engine reaches operating temperature and the thermostat opens?

- Are there air pockets in the system (covered by Craby)

- Are the fans working properly?
You stated that the fans work. By this, do you mean that the PCM does not turn the fans on, but the fan motors work? If the PCM does turn the fans on, do they go at a high speed when the engine gets really hot? Or, did you mean that the PCM properly starts the fans at the right fan speed when the engine gets hot enough?

- Is the radiator cap maintaining the proper pressure?

- Have you observed any coolant leaks at all since you refilled the system with coolant?

- What weight of engine oil are you using and when did you last change the oil?

- Have you made any changes to your car since it started overheating?

- Is this too many questions?