Hot 79
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Joined: Oct 2002
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From: wellington fl
Hot 79
I have a nice 79 corvette with 48,000 miles. I have only had the car for a month and came in first place in my class at the Palm Beach fair grounds. My problem is the car is reading 220/230 on the temp gauge when driving 6o plus miles per hour. When I get back in town it cools down to normal temp (180/185). I will list the things that I have replace: Steward water pump, I went from a three row raditor to a four row, new hoses with spring in the lower hose, new fan clutch, I have tried several thermostats 160, 180 and no thermostat. I have also had the temperature guage check and it seems to be okay. I also put all new seals on the raditor. I took it to a couple of shops and they think I may have a crack in my cylinder walls. I person wanted $1500 and the other one $900.00. I was alson told that corvette water pumps go in reverse direction than other cars. If this is the case could Stewart Components, Inc sent me the wrong water pump even though I went through Ecklers. Please help and thank you.
Drifting
Joined: Mar 2001
Posts: 1,411
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From: St. Louis, Missouri
Re: Hot 79 (Bill Jones)
First of all, I think on C5 engines, the coolant flows in the opposite direction of previous engines but no, C3 water pumps do not rotate in a reverse direction.
You seemed to have covered a lot of bases here but are you sure that the car is runnning as hot as the gauge indicates? Is it even overheating? I would try replacing the temperature sender/sensor. It's on the driver side head and comes out with a 15/16" socket. Also, try inserting a different gauge to verify the coolant temperature.
Also, if you has a cracked cylinder wall and coolant was leaking into the crankcase, it would show up on your dipstick as tan colored drops on the oil
[Modified by Neo Fender, 7:21 AM 10/10/2002]
You seemed to have covered a lot of bases here but are you sure that the car is runnning as hot as the gauge indicates? Is it even overheating? I would try replacing the temperature sender/sensor. It's on the driver side head and comes out with a 15/16" socket. Also, try inserting a different gauge to verify the coolant temperature.
Also, if you has a cracked cylinder wall and coolant was leaking into the crankcase, it would show up on your dipstick as tan colored drops on the oil
[Modified by Neo Fender, 7:21 AM 10/10/2002]
Race Director
Joined: Mar 2001
Posts: 11,322
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From: Living in the Hartland
Re: Hot 79 (Bill Jones)
Couple things to check not coolant related is timing, to far advanced or retarded can cause heating issues, and if you are running lean on your main jets, that also can cause high operating temps at cruising rpms.
Le Mans Master
Joined: Mar 2002
Posts: 7,456
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From: Coming home from Luckenbach Texas
Re: Hot 79 (Bill Jones)
I hate to tell you this...but my car behaved exactly the same way -- and it's normal! These engines run hot primarily because of the high rpms at highway speeds (e.g., 3200-3500 rpm at 70 mph), often combined with the A/C running. I'll guess that your car has at least a 3.55 rear end.
So how did I solve my hot engine issue? It was unintentional -- when I swapped out my TH350 transmission for a 4-speed overdrive, the engine temps at highway speeds dropped 20-30 degrees! :yesnod: Highway rpms dropped from 3200 to 2100 @ 70 mph...
So how did I solve my hot engine issue? It was unintentional -- when I swapped out my TH350 transmission for a 4-speed overdrive, the engine temps at highway speeds dropped 20-30 degrees! :yesnod: Highway rpms dropped from 3200 to 2100 @ 70 mph...
