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Author Topic:   Losing Coolant!
posted April 24, 2004 01:56 AM
Here is the deal. I am running the same cooling system as I did last year and never had any problems. Stock 4 core radiator, stock water pump, 5/8" restrictor and 22 pound radiator cap. Never had a problem.

Well last night was our first race of the season. After coming in from hot laps, the temp was only 185 degrees but I could smell a strong scent of coolant.

Removed the hood and noticed my coolant overflow tank was totally full and I could see how wet the firewall was because it all had come out of the relief valve of the overflow.

Filled the radiator back up and put a brand new 22 pound cap on. Went out for the heat race, temp again only got up to 185 degrees and the overflow again was full. The radiator was almost empty!

What in the world is causing this? I dont see any radiator leaks anywhere but this situation acts like the system is building air pressure, or some kind of pressure, opening up the radiator cap and dumping out all of coolant out the overflow. This is just my theory but I honestly do not have a clue.

Anyone ever have a problem like this? What's going on here? This is a new one to me.

By the way, went out for the feature, was kicking some but, then the clutch went..........oh yea, the overflow again was full and radiator almost empty.


posted April 24, 2004 05:57 AM
Sounds like pressure bleeding past the head gasket or a cracked head. Check compression on all cylinders.

posted April 24, 2004 07:11 AM
i'll second that

posted April 24, 2004 08:18 AM
Get you a pyrometer with engine running and see if the egt's are equal among all cylinders. I'll say you have one about 200 or so degrees cooler than the others. Do a leakdown test on the cooling system. Put 22 pound on her and see if it sets there overnite.

posted April 26, 2004 06:46 PM
No oil in the radiator. No coolant in the oil. Weird. Didnt have access of a pyrometer or leak down tester. I am assuming (hoping) that the head gaskets didnt seal real well. So I am in the process of putting new gaskets on right now. Hope this works.

posted April 26, 2004 10:05 PM
run the motor until warm , pull all the plugs and pressurize the radiator and let it set overnite . have one guy stand on the other side of the motor the next morning and crank the motor , if it is a gasket of head leak the water will come out the spark plug holes of the cylinder with the problem.We had one (406) that the cylinder was cracked at the bottom . It would only burn about a quart of water but would color the redline oil baby **** brown .

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