[Bolen67]

Still having a coolent problem, changed the thermostat but still have crazy spikes. It's 6° out and coolent hits 230 before dropping back down to 170ish then will spike back to 220 or 230 then go back down. Oil temp is go to about 215 as coolent goes up then eventually everything will even out. Till I come to stop, then will restart the process. If really cold out. Sometimes it will only spike once. I'm confused .. please help

 

[ArcticDriver]

How recently did you change the thermostat?

The coolant passages can get air pockets in them and you have to run the engine at high RPMs to push the air out. If you have a steep hill in your neighborhood then go drive up and down it a couple times.

The other thing is what brand and part number t-stat did you purchase?

If you bought from O'Reilly then its likely they gave you a short stem t-stat instead of a long one.
As recently as a month ago their online parts catalog was still indicating the wrong part.

 

[Bolen67]

i changed the thermostat about 3 weeks ago.

okay so i found a hill and ran it up and down the hill 3 times kept in high rpms, seemed like it worked? didnt get past 200 degrees just thinking im sure it will do it again right?

duralast, part number 4899
Alternative part number. 51092 got it from autozone

 

[ArcticDriver]

i changed the thermostat about 3 weeks ago.

okay so i found a hill and ran it up and down the hill 3 times kept in high rpms, seemed like it worked? didnt get past 200 degrees just thinking im sure it will do it again right?

duralast, part number 4899
Alternative part number. 51092 got it from autozone

What year Ford do you have and is this a diesel?

EDIT: OK, I have looked over your past threads and see you have a diesel. The t-stat you have P/N: 4899 is the correct t-stat for a 6.0 but not for a 7.3 Powerstroke (which takes a Duralast 4269).

I also see you thought it might be a sensor ?

 

[Bolen67]

Yes 05 6.0 powerstroke. As far as a sensor I'm guessing.. I saw pervious post about bad theromstat sensors but there Temps show under and never see much about over heating then dropping then eventually goes back to normal.

 

[ArcticDriver]

Well if there were air pockets then they can result in that temperature spike you describe.
If you pushed any air pockets out by high RPMs on the hill then you might see a lower coolant level in your degas tank (overflow tank).

Keep us posted.

Did it spike like this before the new t-stat ?

If the problem continues then it is probably worth swapping that t-stat out for a Motorcraft.

Keep us posted.

 

[Bolen67]

For the hill I found I put in 1 gear and ran it to about 3.5 rpms then shifted to 2 and did it again and I noticed it didn't spike. I'm just hoping it stays like that.
If you think I should go to Motorcraft then that's what I'm going to get. I'd rather have the right part so nothing goes wrong.
I got new tstat because it was spiking.. so I got lost of words when it still was acting up once i replaced it.

I really appreciate the help!

 

[yan7gin]

this is the bleeding procedure for coolant systhem

apperantly the screenshot came up to small....

1. Fill the engine cooling system via the degas bottle until coolant level is between the coolant fill level marks.

1. Run the engine until it reaches operating temperature at 2,000 rpm for 5 minutes.

1. Turn off the engine and allow the cooling system to cool.

1. Add the correct engine coolant mixture to the degas bottle until the coolant level is between the "COOLANT FILL LEVEL" marks.

1. CAUTION: If the air discharge remains cool and the engine coolant temperature gauge does not move, the engine coolant level is low in the engine and must be filled. Stop the engine, allow to cool and fill the cooling system as described.
   Start the engine and allow to idle until normal operating temperature is reached. Hot air should discharge from the A/C vents with the climate control setting to full heat. The engine coolant temperature gauge should maintain a stabilized reading in the middle of the NORMAL range and the upper radiator hose should feel hot to the touch.

1. Repeat Steps 3 through 5 until the degas bottle level is OK.

 

[ArcticDriver]

For the hill I found I put in 1 gear and ran it to about 3.5 rpms then shifted to 2 and did it again and I noticed it didn't spike. I'm just hoping it stays like that.
If you think I should go to Motorcraft then that's what I'm going to get. I'd rather have the right part so nothing goes wrong.
I got new tstat because it was spiking.. so I got lost of words when it still was acting up once i replaced it.

I really appreciate the help!

OK so you got this new t-stat because the old one was spiking. I did not realize this.
Maybe some one will suggest some other possibilities with the 6.0 that can cause this?

 

[Bolen67]

Thanks a lot for your help articdriver!

 

[Bolen67]

Yan 7 gin, thanks! I'll see if it does anything

 

[yan7gin]

Yan 7 gin, thanks! I'll see if it does anything

make sure to open heater full blast in the cab when your doing it

 

[ArcticDriver]

If the problwm persists there is valuable info on this thread:

http://www.thedieselstop.com/forums/f27/overheating-01-f250-7-3l-560977/