Air lock

[jim 44-40]

Any of you guys ever have a air lock in the cooling system of your truck? If so what was going on with temperature gauge,heater etc. If anything

[megasupermagnum]

That depends. It should only be temporary. You do need to bleed the system if you do anything to it. If you have a radiator cap, it is easy. Just fill it up, turn your heat on, and run it with the cap off. It is best if you park at a slight incline. Let it idle a while, then run it around 2000 rpm a while. Top off and done. Sometimes you even have a bleeder screw on a water pump, but I've not seen a truck with one. If you have a pressure tank system with no radiator cap, they self bleed more or less. You just fill the tank, put the cap back on, and run it with the heat on.

As for what air can do, generally erratic coolant temperature is the first sign. If you are continually getting air in the system, it can be a leaking hose, bad water pump, or even a blown head gasket.

[elmacgyver0]

I don't think the head gasket part was something he wanted to hear.

[Finster101]

Depends on what truck. The newer GM diesels can be a bear to purge. Anytime we had to open the cooling system we would bring them up to temp and top them off in the bay and then go out and flog it pretty good, bring it back, park it, let it cool down and then finish topping it off. That by the way is the GM Service Information procedure.

[megasupermagnum]

I don't think the head gasket part was something he wanted to hear.

No need to panic just yet. There's a lot of ways air can get into a cooling system.

[.429&H110]

I had a service truck with soft hoses from the radiator.
Everything was fine until we got hot and revved then the hose pinched and we overheated. At idle we cooled off and ran fine until next time. Fleet mechanic changed the hoses.
Could be as simple as that.

[jim 44-40]

Ya, my temp gauge is showing normal.But both fans starting running on high today which is unusual and I only drove a short distance.

[megasupermagnum]

Ya, my temp gauge is showing normal.But both fans starting running on high today which is unusual and I only drove a short distance.

That's a whole host of possibilities, and I'd put air in the cooling system pretty much at the bottom of it. Could be a temperature sensor (often there are multiple, so one can be bad, but still read good on the gauge), could be a stuck relay for a fan, nowadays I wouldn't be surprised if there is its own module for the fans. It could be as simple as having your A/C max turned on.

[Ford SD]

Ya, my temp gauge is showing normal.But both fans starting running on high today which is unusual and I only drove a short distance.

On Some cars/ trucks if you turn the defrost on the fan will come on.

Did you have the defrost on ?

[waksupi]

We used to put clothespins on the fuel line to stop vapor lock in the old days. Gonna need a real big clothespin for a radiator hose, though!

[Jim22]

I dunno if it will help but the heater in my F150 stopped working. Temp gauge showed normal, engine didn't overheat. So I checked the coolant level. It took a gallon and a half of 50-50 mix to fill it. Then the heater started working fine.

Jim

[Finster101]

It might help to know what the truck is.

[abunaitoo]

Many newer vehicles need to be vacuumed to get all the air out.
Sometimes you can get most of the air out be accelerating a few times.
But I would do it that way.

[jim 44-40]

Truck is 2011 f150 V8 5L

[megasupermagnum]

Truck is 2011 f150 V8 5L

Check fuse 63

[jim 44-40]

Check fuse 63

Will do that

[jcren]

Many newer vehicles have the engine water outlet mounted above the radiator, which creates an air pocket that the water pump can't push out. Look for a air bleeder or pipe plug around where the upper radiator hose goes into the engine. Word of caution, my wifes Jeep with the dodge 4.7 V8 has this layout and a small radiator leak lead to a blown motor. The leak allowed air in, air pocket in the top of the manifold kept water from circulating, but the temp gauge probe is in mounted in the water neck and therefore had no water on it to read. Gauge never got above normal, even when the motor siezed at a stop light.

[jim 44-40]

Learned something about my coolant system on f150 yesterday, works great now that it has the proper thermostat installed.I used a AutoZone thermostat and that was my problem.Guess from now on I'll use Motorcraft parts.