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Old 06-21-2025, 09:17 PM
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65gto69 65gto69 is offline
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Default 1965 GTO water temp not going over 160deg

Hopefully I can get some help on this. Engine specs are in signature, it's a little over stock build.

Anyway had it today to go to a car show, I am in Pennsylvania, temp today was high 80's with humidity, drove the car for about 20 miles and the temp never went over 160 deg. Thermostat is 192 and I am running 50/50 mix coolant.

Let me know if you need any other info.

What is your thought on this and what should I look for to troubleshoot.

Thanks, Mark

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1965 GTO: 467 (Built By Dan Willever), 400 Block, Eagle 4.25 Stroke, Eagle 6.8 Rods, BRC Pistons, Custom Grind Hydraulic Roller Cam, Edelbrock 72cc Heads Ported, HS Rockers, Doug's Headers, Edelbrock Victor 4150, QTF 850 Carb, AutoGear M22 4 Speed, SPEC Clutch and Pressure Plate, 12 Bolt 3:73 Posi.

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Old 06-21-2025, 09:29 PM
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My first suspicion is the temperature gauge.
Electric, mechanical, factory?

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Old 06-22-2025, 06:30 AM
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T-stat stuck?

  #4  
Old 06-22-2025, 08:05 AM
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Default bad stat

when i did my camswap some years ago i used a gutted thermostat for breakin.
temp was under 150 for whole breakin and then after cooldown took her for a nice
ride and temp stayed 160ish. Drove it that way till fall when really needed to get motor
up to temp. Agree i would look at stat first, possibly stuck open.
Also check temp of engine with infrared gauge to verify accuracy to gauge.

Gerry

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  #5  
Old 06-22-2025, 08:41 AM
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65gto69 65gto69 is offline
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thank you for the replies. Those were the 2 things I was coming up with, temp gauge or stuck thermo.

I will check both today

Gauge is aftermarket sun gauge, about 5 years old and under 200 miles on the car.

Coolant still green in the rad and no corrosion present

Thanks,
Matk

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1965 GTO: 467 (Built By Dan Willever), 400 Block, Eagle 4.25 Stroke, Eagle 6.8 Rods, BRC Pistons, Custom Grind Hydraulic Roller Cam, Edelbrock 72cc Heads Ported, HS Rockers, Doug's Headers, Edelbrock Victor 4150, QTF 850 Carb, AutoGear M22 4 Speed, SPEC Clutch and Pressure Plate, 12 Bolt 3:73 Posi.

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