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erikh09

12-31-2012 05:31 PM

engine temperature question

Hello all,

I am scratching my head and hoping someone can lend a little advice. When I have my truck out for a ride (or just idleing for an extended time) my heater hoses both get hot, both radiator hoses get warm, but my radiator cap stays cold to the touch. Thermostat seems to be working (no antifreeze coming from overflow as if it is overheating) but I am not sure the gauge works. Why would the cap not be getting hot? Is the system working that efficiently?

By the way it is a 350 chevy mild street motor with mechanical fan

Thanks for any advice!

68gmsee

12-31-2012 06:47 PM

Re: engine temperature question

Does the top of the radiator or area around the cap get hot?

I'm not sure why, but the radiator water level may have something to do with it. If the truck is not overheating and level is down, there's not water getting to it.
These trucks, for the most part, run a few inches below the top unless you have an overflow tank that keeps the level full..

erikh09

01-01-2013 05:38 PM

Re: engine temperature question

Nothing seems to get excessively hot. The heater hoses do get pretty hot to the touch but that is it. I will have to go check the level in the radiator to see where it is.

68gmsee

01-01-2013 06:23 PM

Re: engine temperature question

Quote:

Originally Posted by erikh09 (Post 5789509)

Nothing seems to get excessively hot. The heater hoses do get pretty hot to the touch but that is it. I will have to go check the level in the radiator to see where it is.

Radiator probably will be about 2-3 inches low if it's like most trucks that don't have the overflow container. I got a new cap and installed an overflow tube on my GMC to keep the radiator topped.

Andy4639

01-01-2013 06:33 PM

Re: engine temperature question

What temperature thermo does the truck have? Are you sure it's got a thermastat? Anytime you run the truck long enough to get it up to temperature and shut it off if it's filled correctly it should always run water into the over flow and then when it cools should suck it back in to the radator.
Check for level and leaks.

geezer#99

01-01-2013 06:54 PM

Re: engine temperature question

Your rad cap doesn't get hot cause it's isolated from the rad by two gaskets. One on the seal to the flange and one on the pressure releif valve. If you have a non-return system like stock your level should be 1-2 inches below the top when cold. That's called an open system.
If you have a return system with a return bottle your level will be absolutely full when cold. THat's called a closed system.
You can have an open system with a catch can That doesn't return fluid to the rad. Only 1 hose into the can.
A closed system has 2 hoses. One hooked to the rad and immersed in the coolant in the bottle and one that vents to the ground.

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