C3 overheating
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Joined: Jul 2022
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From: Missouri
C3 overheating
Hope some of you have some thoughts on this. I have a 1978 that has been having overheating issues. I had to have a new engine installed as well as a new radiator. I have taken the car back to the shop and they cannot pinpoint the overheating. They replaced the thermostat and clutch fan but it still overheats. Driving in the city not a real problem but once on the highway after 20 to 30 minutes the gauge get hot.
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St. Jude Donor '22
Hope some of you have some thoughts on this. I have a 1978 that has been having overheating issues. I had to have a new engine installed as well as a new radiator. I have taken the car back to the shop and they cannot pinpoint the overheating. They replaced the thermostat and clutch fan but it still overheats. Driving in the city not a real problem but once on the highway after 20 to 30 minutes the gauge get hot.
Is my vette stock?? HAHA
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do you have the spring inside the lower radiator hose....there are a ton of posts on the subject and it can be anything form timing to bad circulation and a just plain gummed up radiator and cooling system. When was the last time you drained the block from the bottom and flushed all the rust and crud out and back flushed the radiator?
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Things to look into:
Radiator clean/flush, water pump not working, Thermostat not opening, spring in lower hose, fan clutch not engaging, timing, fan shroud not having the proper seals around it.
Before you start car in the morning take radiator cap off, then turn car on and let it run for about 10 minutes. Look into radiator and make sure water is actually circulating.
Radiator clean/flush, water pump not working, Thermostat not opening, spring in lower hose, fan clutch not engaging, timing, fan shroud not having the proper seals around it.
Before you start car in the morning take radiator cap off, then turn car on and let it run for about 10 minutes. Look into radiator and make sure water is actually circulating.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
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If everything is nee then its almost definitely a mismatched sender to gauge or there is no spring. I have yet to buy a new lower hose that has one included
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Hope some of you have some thoughts on this. I have a 1978 that has been having overheating issues. I had to have a new engine installed as well as a new radiator. I have taken the car back to the shop and they cannot pinpoint the overheating. They replaced the thermostat and clutch fan but it still overheats. Driving in the city not a real problem but once on the highway after 20 to 30 minutes the gauge get hot.
Water boiling point is 212F, at 15 psi that boiling point is increased to 249.8F. A 50/50 mix of water and antifreeze will add 11F buffer to those number so in reality the car pukes out the overflow when the water temp is 260F or higher.
Last edited by Mr D.; Mar 30, 2023 at 05:35 AM.
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And new hoses usually DONT have the spring in the lower hose.
ign. Timing???
How much vacuum advance timing are you running.
Does your vac.can have all the timing in 2 inches below your idle vacuum number?
ign. Timing???
How much vacuum advance timing are you running.
Does your vac.can have all the timing in 2 inches below your idle vacuum number?
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Squeezing the lower rad hose should take the OP 3 seconds, and will confirm the absence of the spring. If it is anything else, I'll be surprised. But pick up an IR temp gun to check, too.