recently, after my long commute to and from work with the heat going, when I turn the truck off, coolant overflows from the radiator cap.

2 weeks ago I replaced the overflow tank and radiator cap. About a year ago I flushed the cooling system, ran restore through the system and refilled with distilled water and no silicate green coolant.

I am really confused, since the truck doesn't overheat and the coolant and oil temps show normal on the scan tool.

 

Stupid question .... this is a 6.0L your talking about, correct? If so what silicant free "green" coolant did you use?

Need year, miles, mods if any, to better help.

 

seriously?

It's the truck in my signature, 212,500 miles. It's stock, except for a SRL tune.
Napa coolant.

 

Sorry can't see signatures on my mobile phone.

 

Uhmm probably another reason he asked is because of your forum name .................

The green coolant is really not recommended for the 6.0L - lots of folks reporting cavitation of the front cover from using it.

Also - they are really not overflow tanks the way this system is designed - flow passes through them to allow gasses to separate from the liquid - they are called degas bottles.

Tell us how full do you fill the degas bottle? The best move next would be to put a pressure gauge on it.

 

If you look in the tech folder there is a full write up on coolant loss diagnosis procedure. What are your eot/ect deltas?

 

never heard that about green coolant. maybe I need to flush again and refill with Cat ELC.

degas bottle is filled the MAX line.

 

You want to use Motorcraft Gold coolant or after a complete system flush, ELC coolant. "Green" coolant is not for this engine and is going to cause problems like what you are describing and some other nasty stuff. Gotta get that stuff out of there.

 

don't remember the numbers, but I can put the scan tool on it again and look.

 

You should only fill it to the minimum line. Ford issued a TSB about that. The heat was causing enough expansion of the coolant to "pop" the relief valve (cap) when it was at the max line. In the early days, this made people start thinking of head gasket or EGR cooler failure, when it really wasn't.

As far as the green coolant goes, it is somewhat debated, but most mechanics I know shy away from it in the 6.0L because of the reason mentioned above (I know a few Techs on here have seen the cavitation).

So, there is no release of fluid until you shut down? Definitely unusual! Do you still have the EGR system? Definitely let us know the ECT's and EOT's. I have a pressure gauge on the tank - it is a very handy tool in troubleshooting coolant loss.

 

ok, looks like the coolant level is over full. I will get the level down and keep monitoring the situation. when It warms up, I will get all the green coolant out and switch to the Cat ELC.