Taking a long time to warm up

[Falcon1772]

2014 Ford Fiesta 1.6 non turbo.
Like the title says it takes a long time to get to 180F. Been monitoring temperature via a bluetooth obd scanner. Takes usually 20-30 minutes driving to get up to 180, it wont get there idling.
I have previously pulled the thermostat and tested it when I first got the car as it overheated on the drive home (was due to a couple pin holes in the lower radiator hose.) And the thermostat opened up at 180F while in a pot of water on the stove.
But the car takes a very long time to heat up to temp. It'll get to about 140f pretty fast but 180 I have to be on the highway for a good 20+ minutes usually. Most of my driving has been this winter and its been from -15f to 20 above.

Are these cars just super cold blooded? Or do I need to replace the thermostat?
On tonight's drive home it was about -15F and it never got up to temp in the 30 minute drive home. I got home, popped the hood and felt the radiator hoses and both were cold, so I would think that means the T-stat didn't open.
Anything else I could look for? Oh and the radiator is about 2/3 blocked off with cardboard.

 

[Falcon1772]

No Codes either by the way

 

[scotman]

The thermostat is a prime suspect. It might be a good idea to go with a "fail safe" type of T stat.

 

[Handy Andy]

Well, let's go a little deeper (SIC) into some other possibilities.

Oil cooler? Working ok? Check the oil, even the dipsticks own condition - when you have cold oil, it tends to gather up moisture from the richer-than-normal fuel mixtures during warm up - which can show up as a "congealed" and foamy deposit on the dipstick along the shaft. The engine needs to have it's oil cooled, yes, but it also needs to be warm / hot enough to evaporate, burn off / remove that trapped fumes and exhaust from the oil itself

You say you drive it 20 minutes on the highway and the upper pipes and lower hoses were not hot - sure sign the radiator did it's job, but the slow leak thru past the "stats" own "stopper" would also show this - from personal experience here.

You'd also have a heck of a time trying to get the motor to idle properly - it has it's own built in pop-up timer motioning this - so it will pop a Check Engine Light on the dash soon enough.

Heater - you getting hot air or just "lukewarm"?

Then it may indicate the thermostat may be "Stuck open" - this long lag or delay even with cardboard sandwiched into the radiator - tells me the Thermostat is on it's way out.

You may "see" it open and close, but if the "stat" doesn't close completely or the "bell/bubble - valve" is missing, that small hole is enough of a leak to push fluid past the thermostat and into the radiator. When you do this test again, set up the stopper so you can lower it into the cold water and pull it out of the hot water with it's ring horizontal, Watch the flow of water thru the stopper. Do this lowering method when it's cold - should be shut completely as you lower it, check that ring - if it's flooded - flows easily past that stopper shows it has no seal - the thermostat is / has - deformed in it's housing. You can try bending the lower immersive holder for it's spring loaded stem as a way to make the stem seat better, it may buy some time - but that may also show it's binding - meaning it's "wax/spring" pressure melt (bourdon tube) is shot

 

[Falcon1772]

heater does blow HOT eventually. But it takes that 20+ minutes on the highway.
If I do go in after the thermostat again, its gonna go in the garbage and a new one will be put in its place. Just kind of a pain since I need to remove the stretchy belt, alternator etc. I'll definitely be getting the tool this time to do the belt right,

 

[econoboxrocks]

Had that issue on my old car, and it was the thermostat. Replaced it, and it worked fine. It was nice to have heat again!

 

[Handy Andy]

It may be prudent to also verify that the new thermostat is / will be - working.

Having personal experience in troubleshooting and their replacement and the "kicking yourself afterwards for not doing this sooner..." - it's a job that is tasking and detailed but well worth the effort afterwards