I have a '97 Z-28 (I'm the original owner) with 120K. Recently I've had problems with overheating that I've not experienced in the history of the car. The "low coolant" light kept coming on and off. I took it to a mechanic and there was zero fluid in the radiator. He replaced the cracked water pump, leaking hoses, thermometer (twice) and flushed the coolant system. It is getting up well over 210 and sometimes almost in the red. The fan comes on, but it doesn't seem to cool the car down. It is particularly bad idling at stoplights or in stop and go traffic.

I read about a sensor for the cooling system, could this be the problem or what else would need to be replaced or checked?

Thanks for any help!

 

This was copied from the "New Member Intro" forum.

Let's help the new guy out!

 

I assume you paid a pretty penny for the work done. I would take it back to the shop and have them look at it. If the system was not bled of air, that could cause problems. I hope he put the right thermostat in for your car. I have found the easier the job, the more problems some shops have. Our cars have very particular things that only happen with them, so I hope the person working on it knows them well. Start by checking the radiator over flow when hot. Make sure the level is where it should be. I had to keep adding coolant for a while after flushing it.

 

+1 on knowing the nuances of the LT1. I'd start by checking the thermostat. The LT1 uses a specific one, and if a normal SBC one is put in its place, it will cause issues. I assume that whoever did the work made sure there was no debris trapped between the AC condenser and radiator. As mentioned above, the system must be properly bled to prevent air pockets. Welcome to the board, BTW.

 

if it was mine my first thought after a new water pump hoses ect. i would try bleeding the system.then would make sure the thermostat was right. but welcome man im geting better with lt1 cars but these guys have helped me multiple times listen tothem and youll get it right.

 

• What is the hottest you have seen the temperature gauge?
• Is the overflow tank staying at a constant level within the hot/cold range? Check the level cold, then check it hot....
• If you check the radiator(stone cold engine), what is the level of the coolant in the radiator?
• Are all the coolant hoses in the correct spot(easy to mix up the overflow and steam return hose)?
• Rent a coolant system pressure tester from Autozone.....apply it to the radiator on a cold engine....pump the pressure to 10psi.....will it hold that pressure without leaking down? If it does not....don't keep pumping it without trying to find the leak....need to find out where the coolant is going......look around the engine as the pressure is dropping to see if you can spot a leak.
• Does the oil look normal? Is there coolant in the oil?

 

There is a procedure for getting the air out. If you need help, let us know. Very easy!

 

Thanks for all of your help and suggestions. I am thinking it is either the wrong thermostat or the mechanic did not bleed out the air. This is the first time I've let an independent mechanic work on my car, all other work has been done by a Chevrolet dealer. So I agree that maybe he doesn't know the Z-28 well enough to work on issues like this. I know he did a pressure test so there were not any leaks. Also, I've heard another reason could be the radiator cap not being the correct psi. Any thoughts on this? Thanks again.

 

Goes back to question # two I asked you earlier.

Also, a lower pressure cap will cause the system to boil faster. If I recall, 18psi is the proper cap pressure for a 4th gen F-body.

 

From another thread earlier this week.

Coolant fill procedure...and it is going to mostly mirror Shoebox's instructions.

First, the way I fill the system can overflow the radiator, because I do run it with the cap off until fully warmed up. So get yourself one of these....

Lisle 24610 Spill-Free Funnel
http://www.amazon.com/Lisle-24610-Sp...ata/B001A4EAV0

• Open both bleed screws.
• Fill the overflow reservoir to full hot.
• Fill the system until a steady stream of coolant comes out each bleed screw.
• Now close each one when the steady stream develops and don't touch them again during the process. There is no need to go jacking around with them again.
• Fill the radiator almost to the top and put the spill free funnel on the radiator.
• Turn the interior heater to full hot and fans wide open.
• Fire up the engine.
• Let it get up to temp, but don't let it get over 200*. If it gets to 212* it's going to boil and get messy....ask me how I know.
• As the engine gets warm, you are first going to see the coolant level rise. This is where the spill free funnel is worth it's weight in gold....otherwise you would have to fill the radiator half full, and even then, I've had it overflow on me before the thermostat can open.
• When the thermostat opens, the level will fall like a rock....add coolant to get the radiator back full.
• As the engine is getting warm, you can blip the throttle some if you wish. This can help the coolant flow get rid of any trapped air.
• Let the temp get to around 190*...then shut off the engine. Let it completely cool with the funnel still on the radiator.
• Remove funnel, top off the system if necessary, put the cap on the radiator, and you should be done.
• Over the next couple of days, before you fire the car up(engine stone cold) check the radiator level and reservoir. Make sure the reservoir is staying consistently at the same level when cold and make sure the radiator is full. If it's a little low, top it off....but at most you should only have to do this one or twice. Most every time, I never have to add any. If you continue to have to top off the radiator, then you've got a leak somewhere.
  

 

Info on the LT1 thermostat from Shoebox's page.



....and that picture is on this page....
http://shbox.com/1/4th_gen_tech2.html

 

Thanks for all the suggestions and how-to photos. I am unable to work on the car myself, but I did take it to a dealership to be looked at. Guess what the problem was? The mechanic who previously worked on it, forgot to hook up the second fan (!). I guess for those of you who wrote that the mechanic really should have good knowledge of Camaros was absolutely right. Or maybe it was just a bonehead mistake. Thanks again everyone! I'm back out on the road, look out!

 

I am sure it was an honest mistake. I know there are many places who would disconnest something else to get you back for another soaking.