cooling problem
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Freshman User
Joined: Apr 2001
Posts: 35
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cooling problem
77 460/f250-About a month ago my temp gauge would suddenly creap up and then go back down. I thought I had a sticking thermostat.I replaced thermostat and problem got worse, 195 vs 180 degree. I took thermostat out completely everything was fine. I thought I had air trapped in system, ran it a day without thermostat and replaced with 160 degree and aftermarket mechanical temp gauge for accuracy. Problem still there, and temp gauge will go from normal to 250 in about 10 seconds then cool back down for a few miles then repeat. I noticed now, duh, that my coolant has air in it. How do I determine if I have a cracked head/block, or a head gasket leaking, or another simple leak somewhere. HELP. This motor was rebuilt less than 15K ago. My first thought is to retorque the heads, any ideas?
Posting Guru
Joined: Jul 2001
Posts: 1,613
Likes: 2
From: Gainesville, FL
cooling problem
JDaniel,
It is fairly common to see foam/bubbles at the mouth of the radiator. Is this what your interpreting as air in the coolant? 1. If I had to guess, your dadiator is either too small or it needs to be replaced.
2. Is your transmission an auto? I recently mixed dextron III with Type F fluid and it caused the transmission to slip which caused the temperature to go up and down rapidly depending on whether I was stopping and going or just cruising at a consistent spped. After changing Trans fluid (type F) and filter everything was fine.
Secondly, Removing the thermostat is a temporary fix for a weak radiator and will take care of a cooling problem for about another year or two. It will not allow your oil to warm quickly which will increase startup wear. Increased oil viscosity will starve HP from the engine.
Good Luck, Have Fun,
KingFisher
It is fairly common to see foam/bubbles at the mouth of the radiator. Is this what your interpreting as air in the coolant? 1. If I had to guess, your dadiator is either too small or it needs to be replaced.
2. Is your transmission an auto? I recently mixed dextron III with Type F fluid and it caused the transmission to slip which caused the temperature to go up and down rapidly depending on whether I was stopping and going or just cruising at a consistent spped. After changing Trans fluid (type F) and filter everything was fine.
Secondly, Removing the thermostat is a temporary fix for a weak radiator and will take care of a cooling problem for about another year or two. It will not allow your oil to warm quickly which will increase startup wear. Increased oil viscosity will starve HP from the engine.
Good Luck, Have Fun,
KingFisher
Post Fiend
Joined: Feb 2000
Posts: 5,130
Likes: 8
From: Brea CA
cooling problem
There is a tester that you can buy for determining if combustion gasses are entering your cooling system. Basically it’s a column of water with a one-way valve that you stick on the radiator neck, a bubble blower. Another way you can check is remove the thermostat, reinstall the outlet but leave the hose off, fill the system with water until it comes out the outlet, remove the belt to the water pump. Now start the engine and let it rum while you look at the outlet. If you see bubbles, you have a leak. I have an exhaust gas analyzer that I stick in the radiator neck to measure any combustion gasses. If you have one and do this, make sure you do not suck up any fluid.
Barry
Barry
Lead Driver
Joined: Nov 2000
Posts: 6,635
Likes: 349
From: Albuquerque
cooling problem
I don't think there should be any bubles in the radiator coolant. An old test for blown head gasket or cracked head is to remove the fan belt and run the engine enough to open the thermostat and look in there for bubbles. If you see any especially if they seem to release steam you have a problem.
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything
1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything
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