Topic: STILL RUNNING HOT
in Forum: C3 Cooling and Heating Systems
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
I HAVE THE HOLES ON THE THERMOSTATE, I HAD THE AIR BUBBLES AT FIRST BUT AS THE CAR HEATED UP IT STOPPED. THE ISSUE I HAD BEFORE WAS THE TEMP WOULD RISE AT HIGH SPEEDS, MY RAD WAS 35% PLUGGED SO I RECORED IT. AFTER ALL THE WORK I DID AS I MENTIONED ON MY FIRST POSTING, NOW IT CREEPS UP QUICKLY AND AFTER LESS THAN A MINUTE IT WILL DROP BACK DOWN 40-50 DEGREES IN LESS THAN 15 SEC, IF I LET IT IDLE FOR A LONG PERIOD OF TIME IT DOES NOT MOVE BEYOND 190. IF MY HEAD GASKET WAS GONE I WOULD BE LOSING COOLANT BUT IM NOT, IF IT WAS A CRACKED HEAD WOULDNT THE TEMP STAY HIGH FOR A LONGER PERIOD OF TIME, IT SEEMS TO COOL TO QUICK IF THE TEMP WAS THAT HIGH.
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Here is a pic of my engine compartment. Is your over flow tank in the same location?Hope this helps.
(large image modified to link)Adams' Apple 2008-05-30 05:21:28
(large image modified to link)
(click to see a larger image)
"It Takes A Little Longer To Do It Right"
"It Takes A Lot Longer To Do It Again"
20111115155328r.jpg)
My '78 is still doing this same thing after new radiator and other stuff. Up to 220 - 230 then back down to just under 200. Just replaced the thermostat, no change. Darn, I think I'll pull it out this weekend and drill that little hole and see what happens. Should I stick with a 195 or go with a lower one?
A tip on thermostats...When I replace a thermostat, I always check it before I install it. Submerse it in a pan of warm water and bring the water to a boil and watch how the thermostat opens. Fish it out of the water, carefully!!!! and do a quick measurement and see if it is opening as far as it should. If not, exchange it where you bought it until you get one that is working correctly...took three attempts once to get one that worked right for a VW Rabbit! Unfortunately, I have not replaced one on the Corvette, so I don't know how far it should open.
There is no substitute for low end torque! 
Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
WAS OUT OF TOWN, I WILL BE BRINGING IT IN AT THE END OF THE WEEK, KEEP YOU GUYS UPDATED ON WHAT WE FIND WITH THE TEMP ISSUE!
Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
DID A PRESSURE TEST ON ALL THE CYLINDERS AND NO SIGN OF HEAD GASKET LEAK OR CRACKED HEAD
. GOING TO CHANGE WATER PUMP, THE SHAFT HAS SOME PLAY AND IS MAKING A LITTLE NOISE, I HOPE THIS RESOLVES THE PROBLEM, KEEP YOU POSTED.
. GOING TO CHANGE WATER PUMP, THE SHAFT HAS SOME PLAY AND IS MAKING A LITTLE NOISE, I HOPE THIS RESOLVES THE PROBLEM, KEEP YOU POSTED.Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
CHANGED WATER PUMP AND NO CHANGE, WHAT DO I DO NEXT?
Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
LOOKING AT MY CORVETTE OWNERS MANUAL IT STATES THAT NORMAL OPERATING TEMP IS 210 AND HARD DRIVING OR AT HIGH SPEEDS 220-230 IS NORMAL. DO ANY OF YOU OUT THERE RUN AT THESE TEMPS. HAD IT OUT TODAY AFTER CHANGING THE WATER PUMP, RAN IT IDLING FOR 25MIN IT HIT 205, TOOK IT OUT AND STARTED TO HAMMER IT A COUPLE OF TIMES IT HIT 220-230, TOOK IT EASY ON THE WAY BACK WENT BACK DOWN TO 210. MY MECHANIC IS TELLING ME IT SHOULD NOT RUN THAT HOT, HE HAS DONE ALL THE TESTS ON THE CAR AND IS ALSO BAFFLED. THE OWNERS MANUAL SAYS THIS IS NORMAL.
Lifetime MemberDo you have a front license plate on car? Had to remove mine because of overheating at higher speeds (75-80+). Sounds exactly like what mine was doing.
Former Member
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Canada
Joined: 3/9/2008
Posts: 164
Vette(s): 70 VETTE 350/300HP, AUTOMATIC, ALL STOCK EXCEPT FOR MILD CAM,LAGUNA GREY, 3:55 POSI GEARS
RAISED THE FRONT END OF THE CAR, REMOVED THE CAP ON THE EXPANSION TANK, RAN IT FOR A GOOD 45 MIN. FILLED THE EXPANSION TANK 3/4 FULL, I HAVE TAKEN IT OUT NUMEROUS TIMES IN HIGH HEAT AND SHE RUNS AT 190, HARD DRIVING OR AT HIGH SPEEDS IT MIGHT REACH 210, MUST HAVE BEEN A AIR POCKET! I LIKE TO THANK EVERYONE FOR THERE HELP1
in Forum: C3 Cooling and Heating Systems
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