Biggiebound

I am trying to figure out a coolant problem now. I just ordered a water pump and after replacing a thermostat, didn't correct the problem of burping the system and it still pukes out coolant when the temperature gets hot. I was told burping the system would correct it but after two tries it just kept puking out. I noticed it would cycle coolant for about 10-20 seconds and then stop so I thought maybe the water pump wasn't working correctly. I am also replacing the temp sensor while The water pump is out. I noticed that my temperature gauge is at the right temperature when driving and cooling is fine but when I stop at stop lights for a little bit the temp gauge rises to about 220-230 but when I take off an drive a little distance the temp goes down but rises again when I stop. If any suggestions on this would also be appreciated. Thanks again for all the replies.

Fatdog2

Are you loosing coolant? This happened to me on my old 93 formula and the waterpump was leaking through the weep hole at the bottom of the waterpump onto the distributor(optispark) when warmed up and I had to feather the car home only to discover a puddle of antifreeze on the ground.When I got on it the car would spit and sputter but when I let off the gas it cleared up.Injuneer is right about the fuel test(when you go the doctor the very first thing they do is take your blood pressure before doing anything)so should be the same for cars I think.Also some previous members did not buy the correct (exact thermostat needed for these cars.It sounds like your coolant problem and running issues could be this.Hope this helps.Also I would replace the gas filter ,check your coil wire and check the coil terminal for white corrosion stuff.The coil wire is a weak link in these cars.If you have an accell coil replace it .I blew one up 10 minutes after install(stuck on freeway lots of fun).My 02 Whew.

Injuneer

https://www.camaroz28.com/forums/lt1...1/#post6975626

Biggiebound

I did get the thermostat that is 180 degree. Autozone said that was the recommendation for that car, I have read that it should be a 160 decree one but the guy at AZ said that the 180 degree was what I needed. My radiator cap seems to be holding pressure but I did notice yesterday that when I leaned my hand on it it sounded like it spewed a little bit.

Injuneer

Stock t'stat is 180*F. A lot of people use the 160* and reset the coolant fan on/off temps in the PCM, and tweak the ignition timing to pick up a few extra HP. Temperature isn't important as being the correct model, with the seal for the hole in the water pump, as shown in Shoebox's photo.

Sounds normal, with a 180* t'stat and stock fan on/off programming. The system was designed to run at 210*F, the center of the gauge. Stock fans come on low speed at 226*F, and high speed at 235*F.

If you are using the correct 50/50 mix of coolant/water, and the pressure cap is holding, there is no way the coolant can boil on its own at 230*F. The boiling point is over 270*F.

Biggiebound

So I need to get the 160*F thermostat because I know it will be the proper fit?

Injuneer

No. The make the correct t'stat in both 180*F and 160*F models. They will look identical to the one in Shoebox's photo.

Many parts stores hear "Chevy V8", and give you the standard t'sat that has been used in the small block Chevy engine for decades. Problem is, the LT1 is a "Generation 2" SBC, and uses a different t'stat.

Biggiebound

Ok, I will get the thermostat, and explain to the people at AZ that there is a difference. I am going to try to get the water pump in tonight. I also wanted to explain myself about the coolant gushing out. I was burping the system and when the temp got up, the coolant would start gushing out and it looked like a volcano erupting. I had my radiator cap off trying to get the air out of the system.

Injuneer

Follow Shoebox's guide:

4th Gen LT1 F-body Tech Articles

Gushing is normal.... that's when you put the cap on.

Biggiebound

Ok I was told to let it Gush because that would ensure all the air was out and then I could fill it back up and then put the cap on because it would settle down and that's when I would know all the air was out. From now on you are the guys I will be seeking info from and not the ones at AZ. Thank you so much for all of the help you guys have provided. I will repost the outcome when I finish the install of the right thermostat and water pump.

Biggiebound

Ok I got my new water pump installed, new correct thermostat installed, and no leaks. I let the temp get up, and seen the thermostat open and added more coolant to top it off. I put a new radiator cap on and went inside the car to see what the temp was, it was Almost to the orange marks on the temp gauge. I shut the motor off and let it cool down. I am still noticing the gurgling in the system. I relieved the pressure from the radiator cap and it stopped after I relieved the pressure. I used water to just try the system out because if I didn't get my problem solved I wouldn't have wasted $35 on dex-cool coolant. Would this make a difference? Also I took my cooling fans out and tested them and they both worked. When I got everything back together the fans would only kick on when I turned the air on. Not when it got up to the 210-230 temp. If anyone could give me advice I sure would appricate it. Thanks so much for all the great info. Fred, shoebox, and injuneer you all have GREAT info and step by step options that was a great help.