Trapped air in the cooling system?

[LaGrasta]

Is trapped air in the cooling system a reality? If so, how do you get it out? I vaguely remember a "bleed" screw on the side of the block.

 

[66 Fastback]

Yes, I have had it on other cars but it has not really been a problem on my inline Fords. I am not aware of an air bleed on the coolant system for the inline Fords.

But to get rid of it, I take the cap off, start the engine and run it till it is warmed up and the thermostat opens. Then raise the rpms and allow it to circulate the air out. Don't reve too high or you will surely overflow. Also, if the engine runs hot anyway, you can expect it to overheat when doing this operation. On some vehicles I have put the front wheels on ramps and run the engine in this position which helps make sure the radiator cap is at the high point of the cooling system, just in case it is not.
Doug

 

[wallaka]

Right, the radiator cap is the high point, so just burp it out with the cap off. The block bleed screw isn't high enough to do any good, mostly air gets trapped in the head.

 

[Henning_1966]

I have never had problems with my inline not wanting to burp. But I have had problems with my van not wanting to burp. I find this funnel to be a nice tool to help. http://tinyurl.com/4lgdo7

 

[LaGrasta]

thanks, i'll see what happens with that.

 

[wsa111]

Drill a small hole .060 at 12:00 on the thermostat flange. That will bleed most of the air when just filling the system.
Or
Open the thermostat by hand & place 1 or 2 aspirn pills to keep the thermostat open before you start the engine. After the engine warms up the pills desolve & the thermostat works normally.
I will check at work tommorow cause some oem thermostats have a poppet valve at 12:00 on their thermostats. Bill

 

[Asa]

the radiator on my mustang has a provision for an overflow tube, i just hooked it up to a water-bottle w/coolant in it for a makeshift overflow container, that way it'll burp itself and you don't really have to ever worry about it

 

[grocery getter]

it's a strong reality on newer cars. in the 80's, honda put a bleed by the
t-stat housing. a guy at work has to bleed his 2002 sentra a couple times a year.

 

[LaGrasta]

I'm starting to think I don't have air in the system. I already have the 1/8" hole drilled in the stat as well as an overflow set-up that seems to work as it should.

I questioned this in the first place because I have been running hot on any day over 85°. At speed it seem runs hotter than stopped. I have an electric fan as a pusher that will run even at speed thus actually blocking clean air. I'm starting to think I need my mechanical fan back...

 

[66 Fastback]

When I have had a significant amount of air in the system the temp guage will read normal until the engine warms up and then a while later it will spike very hot. I think it is because the temp probe is stuck in air and then once the thermostat opens a slug of hot water or steam hits it since the coolan flow is reduced with the air in the system.
Doug

 

[ludwig]

I wonder if the impeller on your water pump is slipping. Also, maybe you don't have enough fan to cool well. That and a shroud of some sort. The fan is only necessary at low speed or stopped, as I understand it. So maybe you have enough fan, but the water is not getting around. Are the hoses to your heater hooked up? That will add cooling.