Overheating 2008 fxt onhot day up hill

[moshe_levy]

Hello every one
 
So my car overheated 2 days ago when the out side temp was 40C.
 
It raised up alittle bit from the dead centre,i didn't stop and when the hill ended the gauge gotback to the middle as usual.
 
I have mishi rad,new cups,new pipes,funs working at the right temp,new stat,the only thing i didn't replace is waterpump and HG[emoji26].
 
When i got home 5-7 minutes later i pumped the hood and the coolant raised alittle bit on the expantion tank,than after it cool down it get back to the same spot.
 
I didn't have the monitoring the same day so by the original gauge i think the coolant temp was on 102-104C.
 
The speed of the car was around the 100kmh,it's 4EAT and i have trans oil cooler and engine oil cooler,the temp of the oil cooler was 100( i have warning at this level) and the oil pressur was around 60-70 PSI.
I don't have oil in water or water in oil and i don't lose water.
 
Hope i gave you all the information.
 
What should i do next??
 
I have to say that same hill less temp outside no overheating accur it stays around the 90C.
 
Thanks everyone
 
Sent from my MI MAX using Tapatalk
 
Sent from my MI MAX using Tapatalk
 
 

[moshe_levy]

somebody any suggestion...!?

Sent from my SM-G610F using Tapatalk

[Mr B]

What thermostat ? I tend use only original as aftermarket not so good in water flow design and rated temp opening, you could try lower temp rated thermostat too .
if a 2.5 then head gaskets very common and don't have all the usual symptoms associated with head gasket failures .
 

[moshe_levy]

i'm with stock one, i have mishi one i will try to replace between them,and yes it is the 2.5L, do you think i need to do HG tests?

Sent from my SM-G610F using Tapatalk

[Mr B]

What does the head gasket joint look like from under the vehicle ? totally dry or slightly damp sticky mess ?

In early stages of leaks head gasket leak tests don't always prove anything unfortunately .

[moshe_levy]

there is alittle bit of oil over the joints coolant leaks i don't have and i don't add coolant or oil ever.
some thing i can think of and let me know if i'm right or wrong,is my rear muffler and i'l explain.
i have 3" downpipe decat,3" mid pipe and i replaced my rear muffler with some tiny mini one so i can build mine may be cause the pipe is so small inside it bscome bloked and the engin gases can't be released and it causes the heads to get warm on hot days and when climbing hills?

[moshe_levy]

here is the muffler finished,hope to install it tommorow or sunday

 

 

 

 

[Mr B]

Back pressure in exhaust certainly would not help it, does it build boost okay, does it feel similar power on boost ...

[moshe_levy]

now i'm with the new 3" rear muffler and i feel the difference now,the boost is coming brutality the sound is better and maybe it decrease some degrees of coolant and engine oil.
hope it will solve the overheating also

[moshe_levy]

here it is lnstall on the car