Overheating in subzero temps...

[Ford4life32]

Started my truck this morning, it was about 2 degrees out and i let it run for about 10 mins before i left for work. Driving to get my coworker the truck was heating up to normal temp and there was no heat blowing out of the vents just cold air even at norm temp. Then all of a sudden the temp gauge just started going up and up so i had to pull over and let sit until it went back to normal to then park it at my buddies house. after work drove it around to see if it would happen again was driving for like 15 minutes it was fine at norm temp heat blowing out the vent... so i hit the gas not wot but close to it. That made it happen, gauge started to rise so i turned down a side street and it went back down but would then fluctuate between norm temp and 3/4ths of the way up then it just stayed at 3/4 line... im confused, any help at all would be appreciated thanks! :thumbdwn:

 

[2000StreetRod]

diluted antifreeze?

The first thing I can think of is the antifreeze is too deleted for the temperature and the radiator is partially frozen.

 

[07LTDDSM]

thermostat?

 

[drdoom]

I agree with streetrod, your system is freezing up. Not good.

 

[Rickademus]

If you antifreeze strength is ok . Then I would replace the waterpump you have to suspect the the impeller is free wheeling on the shaft.

 

[Ford4life32]

Thanks for the input guys! Heres an update. I took it in to our mechanic that we go to and he had it running for an hour and a half, drove it for 8 miles never went over normal temp. He tested the antifreeze and its good for -12 and he checked the level of the antifreeze and its full.... so now im lost. I dont think it was the water pump because you would think it would have overheated on him.

 

[2000StreetRod]

stuck thermostat?

Since your antifreeze tested good then I agree with 07LTDDSM that your thermostat stuck closed.

 

[Rickademus]

I would be keeping a close eye on your cooling system from now on coolant level heater fan blowing hot etc

 

[Ford4life32]

Streetrod, Is the thermostat then bad if it stuck closed one time? I dont know if it would be the thermostat because it was replaced less than a year ago when my thermostat housing went. It hasn't overheated since, I'm going to get a coolant flush just to be on the safe side. Maybe it was just too cold for the coolant.. And i will definitely keep an eye on it for a while now thanks Rickademus

 

[Tech By Trade]

If it was too cold for the coolant you have a cracked block because that what happens when water freezes. It probably is the thermostat as they stick closed when they go. Easy to change, just let a couple gallons of antifreeze out, pop off the thermostat housing, swap the thermostat, torque down the thermostat housing and put the fluid back in. Probably should cost you about 10 bucks and 20 minutes of your time.

 

[2000StreetRod]

normal warm up?

Does the engine warm up normally now? Some thermostats fail stuck open when overheated.

 

[pzy3339]

I don't think a bad thermostat would cause the loss of heat in the cabin. Doesn't the coolant route for the heater cores run on the main loop of the coolant system??

As in not between the engine block and radiator.

You get heat in the cabin long before the thermostat opens up.

That said, the thermostat is a 5 minute, $20 job. Easy and cheap to rule out.

 

[Ford4life32]

Yes the engine warms up normally and stays at normal operating temp. Have not loss heat in cabin since the overheating and it has not overheated since then. I will replace the thermostat just to be on the safe side

 

[07LTDDSM]

:

...Probably should cost you about 10 bucks and 20 minutes of your time.

Thats why I said it. Cheapest fix first.

 

[Ford4life32]

So i thought i would throw an update in this thread. i didn't replace the thermostat since i just didn't have time and it never happened again. I ended up getting a coolant flush at the corner oil change place and everything seemed fine until it got real cold again.. like -15 -25. I would start it to go to work i would drive 20 miles to work with no heat at all but the truck would be at normal operating temp. this happened 2 days in a row.. the second time i had no heat i was pissed and fed up so i thought something was just clogged somewhere so i hit this "jump" in the road pretty fast and as soon as i landed boom heat came through the vents. that weekend i went to drive up to Atlanta MI to visit some family and i had started my truck and as i was loading things up i heard a weird noise coming from the front end looked underneath and coolant is leaking on the ground.. Looked in the overflow reservoir and it was frozen... had to take Gfs jeep up north, you could say i was pissed. After that i obviously needed to address this problem it finally worked out in my work schedule to take the truck in to a shop where my buddy works. Tested the coolant it was only rated for 10 degrees above zero..... Got it flushed and tested there it was good for -37 degrees. everything is running as good as new now you could say i had a few choice words for the shop that did my previous flush..

 

[MotorCityFats13]

they gave you a flush and fill and it only tested for 10f... they must have tried to save money and fill the system with a 20% mix i would avoid going there again and tell everyone you can... my heat in my 07 4.0 is terrible and anything below 10f it gets worse... I think the core is clogged because the thing had a leaky tstat housing when I bought it and I think they were trying to use stop leak to fix the problem..... I changed the housing like 3 days after I bought it because the top of the engine was a green lake and grill would steam off and on...