Originally Posted by jmarthaler
Hi I just joined this awesome club and am looking for some advice about my 93 vette lt1 that suddenly is boiling the coolant out of the overflow tank. Drove it to the local trans repair shop for a zf manual 3rd gear synchro replacement. The repair was completed and now I can't leave the shop due to coolant overheating and overflowing coolant out the resivor. I replaced the thermostat in the parking lot and refilled tank with spill free funnel. At about 213 degrees the coolant will raise out the funnel and spray out. the funnel has a white residue that is like paperlike feel to it? I am wondering if the previous owner tried to repair a gasket problem with some type of sealer and now it let loose? any help
You could have a break in the line somewhere. Your hitting waters natural boiling point (assuming your gauge is off) and it's boiling. Pressure makes the boiling point higher.
Just to be thorough check all of the hoses, and the connection at the radiator. Particularly on the return side. I had something very similar happen on my 89. Turned out that the plastic nipple on the side tank on the return side of the radiator had broken off inside the hose and pushed the hose very slightly
open relieving the pressure in the system with no discernable leak. Didn't find it when I got in the driveway that night.
It took me going through everything fearing that the headgasket on my L98 finally cut loose, on the hoses until I got to the front end. Squeezing the hose, it plum fell off the radiator and I found the broken shards stuck in the hose.
Not saying that you'll be that lucky but check your hoses etc. Failing that....then yeah probably head gasket.