overheats when I turn it off then on

[jimmyess333]

Sometimes when I stop for gas on a really hot day the temp will read about half way when I turn the engine off but the guage will be pinned for up to 30 seconds and the temp light will be on when I turn the engine back on.
If I leave the truck idling it's never a problem, only if I turn it off and on.
It only happens when I stop the engine for a few minutes, if I'm away from the truck for 10-15 minutes or more it's ok.
Is this normal?

After reading some other posts I thought maybe I need a new radiator cap.

 

[jimmyess333]

I just thought of something...
I don't have an actual radiator cap, just a cap on the filler/overflow bottle with that strange purge/flow-thru design.
I have no idea how this actually differs from the old shool design of a cap ON the radiator and an overflow bottle that does not flow through.
So, I could me missing something here.

 

[jimmyess333]

Nobody?
Hmmm, none of my other vehicles did this except maybe my slant six back in the day.
But that temp guage would settle down after 10 seconds tops.
This one does it for 30 seconds or more and even tripped the overheat/limp mode once, where the engine light comes on and it doesn't run on all cylinders until it cools down again.
Is this normal for Rangers?
Do I need to upgrade the cooling system?

 

[cammeddrz]

your engine is hot and has coolant passing through it, the second that you shut of the engine you also shut off the flow of coolant. so the coolant remains sitting stagnant in the engine and picks up a lot more heat than it would if the coolant was moving. that is why once the engine gets started up that coolant that picked up all that heat starts being circulated out of the engine and therefore away from your temp sensor. but it takes a minute of running to circulate out that hot coolant and replace it with colder coolant. that sounds exactly like whats happening

 

[koda6966]

What he said, plus your fan turns off when you turn your engine off.

 

[jimmyess333]

Ok, that all makes perfect sense and I've seen it before but I've never seen it happen this badly before.
I guess what I'm trying to find out is...does this happen all the time with this engine?
I don't want to ignore it if it's not normal and warp the head.
I'm also new to the south so im wondering if I need a bigger radiator here.

 

[mr_wright]

I've had at least 3 trucks that have done this. it's totally normal. Relax.

 

[bcost882]

well see a bigger radiator wouldn't help cause no matter wut the engine stops the flow of coolant when you turn off the engine because of the engine driven driven water pump so think of it as the coolant stopping in its path and just soaking in the heat of the engine. i've never seen it before so hope your sort it out bro going by wut camm said

 

[jimmyess333]

well see a bigger radiator wouldn't help cause no matter wut the engine stops the flow of coolant when you turn off the engine because of the engine driven driven water pump so think of it as the coolant stopping in its path and just soaking in the heat of the engine. i've never seen it before so hope your sort it out bro going by wut camm said

True, but I was thinking the engine would stay cooler before turning it of and maybe not have as much stored heat to soak into the stopped coolant.
Just a thought...

 

[press 1 for english]

I've had at least 3 trucks that have done this. it's totally normal. Relax.

NOT NORMAL
Heat soak to that degree, is not normal.