c1 overheating

[Paul Bowers]

have 57 with new rebuild ,including new radiator, this weekend was at car show were had to stay in line long time ilding car gage reached about 200 degrees and spilled antifreeze thru overflow after shut off, a radiator shop suggested replaced 7 lb. with larger lb. cap with would make car run cooler and prevent spill thru overflow tube, does anyone agree with radiator shop as to making run cooler and stop spill over thanks in advance
paul

[Dave Suesz]

[Mike M.]

Re: c1 overheating

agree with dave. if it was truely 200 deg, it ought not puke coolant unless you overfilled the radiator system initially.200 deg not at all excessive fro a recently rebuilt sbc. mike

[John O.]

Re: c1 overheating

Hi Paul

I had a simliar problem with my 62 vette. It turned out that I had the overflow tank filled all the way and there was no room for the expanded antifreeze to go except out the overflow hose.My gauge read 220 plus...I changed the sending unit and now it works fine.My temp does not go past 190 degrees. I was giving these answers by guys here on this site. I don't know much about 57 vettes. Do you have an expansion tank? If not,is the anti-freeze level where it's supposed to be?.Do you have the correct mixture? What about the thermostat, is it ok? Also I was told that sometimes on a new rebuild,it will run hotter until break in of the engine. I would not recommend going to a higher pound cap.That can cause problems like hose leaks at the clamp areas or even blowouts of the hoses.Use what GM says to use.Well I hope this helps.

Good luck...John

[Paul Bowers]

Re: Bad idea...

thanks all you guys for your responses , but if I did have to much antifreeze in radiator should the level be just at the lower neck of spout when cold or were is a good level
thanks paul

[Roy B.]

Re: Bad idea...

(the level be just at the lower neck of spout when cold)YES! 200 is not all that bad doing what you did , sounds like you need a new Rad. Cap

[Paul Bowers]

Re: Bad idea...

thanks Roy,

while I'm at it I may replace my senscor I bought this one from CC it looks like orginal but it is poss. it may be inaccurate, do you know of a outlet that has orginal looking but are considered really (accurate sensors), also can the accuracy of my dash guage be somehow checked or recalabrated thanks
for imput
paul

[Roy B.]

Re: Bad idea...

If you wont a real one that will work correct , I don't know about repro's look at 56 to 64? Chevy car to truck, same as corvette. They made a million of them and it cant be that dang hard to locate (try Chevy guys, not Corvette guys)for the gage use that heat gun thing to check the water temp.

[John H.]

Re: Bad idea...

First, determine what the temp gauge is really telling you (they're notoriously inaccurate); shoot the upper radiator hose just above the thermostat housing with an I.R. gun and compare that reading with what the gauge says at the same time.

Second, don't fill the radiator up to the top - that won't leave room in the cooling system for expansion of hot coolant, and it will probably "puke" through the overflow hose while it's "hot-soaking" after shutdown. You'll note in the owner's manual that it says to leave the (cold) level at least 2" below the top of the radiator, or leave the cold fill a pint or quart low to provide room for expansion. It'll find its own "happy level", and won't "puke" any more.

[Dennis C.]

Mr. Hinkley, as usual, is exactly right... *NM*