red95ssclone

Its a 1995 lt1 with 116k miles. Coolant is disappearing. I made sure to bleed the air out of the system, replaced the thermostat, replaced the cap. I cant see any leaks around the radiator nor any coolant on the ground. If i let the car sit for about 30 min after driving and turn it back on again the low coolant level light comes on.
At first i thought it might be the overflow not letting coolant back in so i measured the amount of coolant in the overflow before i shut the car off. I came back in 30 min, checked the overflow tank and it was at the same level. Turned the car on and the light was back on. Now it sometimes takes 3 times to start. When i go to start it, it almost acts like it is vapor locked. I pulled the plugs and there is no sign of coolant in the cylinders. There is condensation in the oil fill cap and inside the valve cover that i can see with a flash light, but there is always some condensation there, im just not sure if it is a normal amount.
I am a college student without access to very many tools because they are 150 miles away at the parents house. Any ideas? I need to know asap to avoid more damage to this pos.

Thanks in advance, Red

s10469

Be sure no coolant is in the cylinders becouse coolant doesnt compress and it will cause the wet cylinder to vaperlock and it could hurt the rod or worse.Also, the white stuff under your oil cap is usually a sign that moisture (coolant perhaps)is present in your oil.

red95ssclone

I pulled a plug and there was no sign of moisture.
My description of the vapor lock. When i went to start the car, it turned over maybe an eigth of a revolution and then stuck. a little more suddenly than if you were to stall it.......

s10469

Did you mpull the right plug? Im guessing you did. I pulled all the plugs and put paper over the plug holes, disconnected the coil wire, and turnd the engine over for a couple of seconds and checked the paper to see if any thing came out of the spark plugholes(water,oil gas). You might have a different problem though.

moparman

Just because the low coolant light is on does not mean the coolant is low. It's a common problem with the low coolant sensor. Best place to check for low coolant is the radiator. Check the radiator level a couple of times after the car has cooled off.

red95ssclone

My coolant sensor appears to be working. Everytime the light comes on, the radiator is low. I guess what im gonna have to do is drain the oil into a bucket and let it sit ovenight to see if any water is in it. Thanks for the replies, keep em comin.

LastZ4ME

Mine is doing the exact same thing. I think it's just a faulty sensor cause the coolant level is good after it cools off. Light just comes on sometimes for no reason. Funny, it seems it everyone on this thread has a 95....Hum.

red95ssclone

Any more suggestions?

moparman

Get a pressure tester, Autozone loans them out, and pump up the radiator and see if you can spot any leaks.

red95ssclone

I used a pressure tester for the coolant system and put 18-20 psi in it. Pressure held and there were no signs of any small leaks. I dont believe that pressure would be lost if it was a leak in the head gasket around the combustion area of the cylinder. Im guessing that i would have to remove the plugs so that the pressure loss could be read on the coolant system pressure tester.

If anyone has an idea what is wrong because i really dont have the time to start pulling the heads off, intake off, etc.

Again, The car is losing coolant and it is not going on the ground. The car overheats spuratically. Sometimes after letting the car sit after driving(with temp ok and coolant level ok) I will get back in the car and the coolant level light is on and the level is low. After adding coolant and bleeding the air out of the system, it happens again. The oil level is normal and the oil looks normal.

Thanks alot guys, i gotta fix this tommorow (its raining right now) so i can get to class monday.

red95ssclone

The rain stopped, im gonna try and figure it out. Any ideas?

moparman

I chased after a "mystery" leak for a few weeks a couple of years ago. The pressure would not fall when pumped up. Finally, on a really hot day, after I had driven a few miles to the doctor's office, I came out and there was coolant underneath the car. Fortunately, a buddy of mine had a garage just a couple of blocks from the doctor's office. Drove the car there and put it on the rack. It turns out the plastic radiator tank had a crack in it. Theory is the crack in the tank would only expand when the coolant was hot, and contract when the engine cooled. You might go to looking for a crack in the radiator. I think I've seen some other posts about this happening to others.

red95ssclone

I had the passenger side tank crack on me about a year ago. I will def double check because i didnt think about the expansion of the plastic when up to temp. I dont think that this is the problem because i have kind of checked for water around this area.

oneslowz28

These statements lead me to believe that you have a blown headgasket. Pull all of the plugs and check for moisture. When a headgasket blows it doesnt blow across the whole bank it blows on 1 or 2 cylenders. So pull all the plugs and check.
The blow on the head gasket may be so small that it only lets the water enter the cylender when the car is running and the compression from the piston pushes the head enough to lift up.

You have to pull all of the plugs like I stated above.

93hotZ

I just replaced my radiator because of small cracks in the plastic tank on the passenger side. Cured the same problem you are having. 165 bucks at oreilly's with lifetime warr.

93Z W/all the goodies