I've got a SBC with a aluminum radiator and electric fan. The temp. gets up to about 185 and steam comes out of the radiator but the fan doesn't come on. But if you shut the engine off and let it sit for a couple of minutes then turn the key to the on position the fan starts up. Then start the engine up and everything is fine. What's up?
Cooling Advice
- Thread starter KAA
- Start date
Don'tCallMeJimmie
Member
You've got trapped air that isn't purged, a weak cap, and/or need an expansion tank. 185 isn't enough to cause boil-over.
Trapped air is what I thought but took the cap loose and ran it for a while and changed the anti freeze. I have a tank but how much is suppose to be in it?
Where is the temp switch and what make? Is it a tube that sticks in the radiator, or does it screw into the block, and is it a fixed temp or adjustable? Did it ever work right, or is this a new problem?
And where is the temp sender for the temp gauge? And what is the pressure rating for the radiator cap?
Have you made any changes to any of these items recently?
And where is the temp sender for the temp gauge? And what is the pressure rating for the radiator cap?
Have you made any changes to any of these items recently?
This is a new build. The sender is in the intake. It is a fixed temp. Is there suppose to be any fluid in the expansion tank?
Francis Blake
Active Member
The expansion tank receives coolant when the radiator burps some out but sucks it back when it cools, it doesn't matter if there is a little left in there.
At what temp is the fan supposed to come on? Sounds like when the engine is allowed to sit and heat-soak for a minute the temp at the switch is enough to switch on the fan. So you may not have a problem there. The steam could just be due to a low-pressure cap; what is it's rating?
I'll check tomorrow not sure.
I just put a manual switch on mine and just leave it on while driving. When I used the temp switch it seemed to cycle on and off constantly and drove me crazy. Now it runs nice and cool and never overheats. I'm running a 195 thermostat but it usually runs right around that temp. even in high 90s air temps.
2old2fast
Active Member
Set up correctly & functioning properly you should not need a fan at speeds over 30-40 mph. Fan should only come on at low speeds or idling. If you're having trouble, something's not right in the system. As an example.. my engine is a .060 over sbc stroker [388"] w/ 10.5 compression..I've never seen over 180* on the road , fan comes on at 210*,off at 190* , mainly at stop lites...
dave
dave
Wild Mango
Member
What he said. The electric fan is only there to create a breeze through the radiator when the motion of the vehicle doesn't. The whole idea of an electric radiator fan is that it only runs and consumes power when needed.
Screaming Metal
Active Member
What they said!
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