My 96 T/A is spewing coolant out of the reservoir tank, but is not running hot at all. I had an overheating problem, my fans were not coming on, so I wired up a manual switch to turn both fans on high, so now it is not overheating. Then one day it started spewing coolant out of the reservoir, so I replaced the thermostat and the ECT to try and fix my fan problem. The car quit spewing fluid but the fans still did not come on, so I am still using my manual switch. Tonight when I was driving, I parked the car and when I got out I smelled coolant. It was leaking out of the reservoir, but wasn't running hot at all. So I re-filled it, bled the lines, I opened the bleeder screws while the car was running, not sure if that is right or not. So after I filled it up, I was going home, and stopped to get gas, and it was started spewing again. I know I bought the correct thermo, I got a 180, and it was extra long. I am stumped. Sorry so long.

 

Is the coolant boiling hot... or is there an steam comming from the resivour?


What's the highest temperature that your car is reading after your manual fan upgrade?


Only 2 things I know of cause a regurgitating resivour...

1. Over filled system
2. boiling Coolant

 

With the manual fan switch, it generally runs about 185 to 190. Never gets about 195. There is heat coming from it, I am not sure if it is boiling over or just running out, I thought about that to, that maybe my radiator was to full, but I wouldn't think it would leak out this much, When I open the radiator cap, I look down and I can't see any coolant, I know there is some in there, but I can't see it.

 

If you can try removing your thermostat and take a look to see were your coolant level is at on the water pump. That's the best place to check first for low coolant levels. Air usually likes to hide in there.. so it's something to play round with.


When you take the cap off your radiator you should be able to see coolant. less than an inch down from the top.

I would either remove the thermostat... grab a funnel and fill the water pump with coolant.... or fill the car with coolant at the radiator.... If your lacking coolant in the radiator... I'm willing to bet my ZR1's your lacking coolant in the pump.

but you would know if there is that much coolant missing right away... the coolant that spews out will be boiling hot.

I've never had a problem with my fans... but if your fans aren't turning on, than somethings keeping the computer from recognizing the temperature of your water if it's boiling over, and registering 180-195.

 

I will try that tomorrow. Could it possibly be that I have to much water and not enough coolant in the mix?

 

#2 just made me think about the radiator cap. Doesn't it maintain the pressure to prevent the coolant from boiling? Bad cap maybe? May not be it, but at least it's cheap!

 

Yeah, the more a liquid is pressurized, the higher the boiling point is.

 

Tomorrow I am going to try adding more Dex-cool, if it does not fix it, I am going to try a new radiator cap, will one form autozone work or do I need a GM one?

 

The autozones work fine...you just have to make sure thier on securly... but if you can get it cheap grab a GM one.

 

Don't get the autozone cap. They aren't rated to tolerances correctly. I had the 18 # cap, and it was only holding like 6 psi brand new. The car was boiling over from the day I put the cap on (The 10 year old GM cap it replaced was doing better!)

I got a new GM cap, no problems since.

Also, if it isn't the cap, you could have a leak somewhere else, like under the TB, I had a small one there, because the gasket had eroded. Just did a TB bypass to fix that one...

You probably don't, but it doesn't hurt to check.

 

Don't get any cap except a GM one. I went through two O'Reilly caps and neither of them worked. I was having the same problem you are and once I put a GM cap on it was fixed. Try the cap first before you go spending money on more antifreeze and then watch it pour out again.

 

I had the same exact problem you are having in my 96 T/A. I thought there was air in the lines so i bled em a million times and still every once in a while it does it. I was never recommended to change the cap. Maybe i will try that as well and see what happens.

 

I changed my cap out and put a new thermo in, both from Autozone. Well, It was still doing it after both things, but it would still run at a good temp. Today, my thermostat didn't open and I spewed coolant everywhere, the car got up to about 245 to 250 and my check gauges light came on. So I shut it off. I am going to go buy a new GM cap and thermo tomorrow.

 

Just for grins, you could drill 2 small holes in your thermostat and see if that is culprit. You could also put the thermostat in a pot of boiling water to see if it opens up? If you're going to buy one anyways.

 

Yeah, I had the old one that I took out of the car lieing around, so I stuck it back in, it hardly works, but works a lot beter than that other one, and will get me through today until I can get over to the Chevy House to pick up the one I ordered this morning.