2011 Fiesta SE overheating/ boiling coolant

Yesterday, after parking it from a short drive, I noticed the radiator fan still running, and a hot coolant smell. Popped the hood and the coolant reservoir was bubbling, a little bit of steam coming off the rad. cap. The reservoir low in water/coolant. Drips on the ground directly underneath, but nowhere else under the car.

This morning, I check it again, cold. Reservoir a little lower. I fill it up with distilled water to the MAX line. I decided at 80k miles, a good time to change spark plugs & wires. Cheap and super easy to get to, took no time at all. With the water filled up and new spark plugs, I let it idle with AC on, with my infrared thermometer, I tried to see if I could measure a temperature differential between the inlet of the radiator and the exit. I was getting 86.3 - 86.7 degrees throughout the radiator, couldn't accurately measure the inlet/outlet pipes.

Drove around neighborhood, and parked, the reservoir rose up from the max line, to where it's at in this picture.

i.imgur.com/AFMZYoA.png

The top tube going in the tank was HOT, boiling water trickling in, and steam coming from cap. After shutting the engine off, a few minutes later the water level when back below the Minimum fill line. Where it was this morning.

>Has gotten warm about 6 months ago
>Water pump and cap changed about 6 months ago
No problems until yesterday

Other urls found in this thread:

fiestast.org/forum/fiesta-st-maintenance/1923-car-overheated-twice-2-weeks.html
twitter.com/NSFWRedditImage

Id lean faulty waterpump.
Even if its new, it can still be out of box failure

Needs a flush you fucking pleb

Thanks, I will try to see if I can tell if it can pump at all

With the motor completely cold, take off the radiator cap/coolant reservoir cap and start it. Look inside the radiator/reservoir and see if you can see fluid moving. Have you consulted the dealer?

>he doesn't monitor his coolant temp with a bluetooth obd2 adapter and torque pro

Rfound this forum post about a 2011 Fiesta ST
Apparently the plastic radiator had an improperly machined tab inside, causing poor flow.
Need a new radiator most likely.
fiestast.org/forum/fiesta-st-maintenance/1923-car-overheated-twice-2-weeks.html

Two likely possibilities

First is that the coolant does not have a sufficiently high boiling point due to poor mixture control. Second is that the cooling system cap is faulty and doesn't hold pressure on the system and allowing the coolant to boil earlier than designed.

Or both I suppose.

Drove around the block again, got accurate radiator temperature readings, at the top, passenger side, went from 190 right after parking, after a bit of idling, went to 210, and I shut it off. The reservoir filled up almost to the top.

Bottom of radiator at both corners, 107 degrees.

I believe this means the water is not flowing. SO either stuck tstat, or water pump is not pumping. What tells the W.P. to come on/ off?

Also thanks guys for the swift responses.

take it to the dealer.

Does the heater work?

see

funny, looking at the FiST forum and seeing the first page FILLED with all the problems MY car has, or has had.

I have a '14 OP, does your temp gauge go up?

Check your serpentine belt for wear. They like to crack badly before failing and could be slipping over the water pump pulley.

Has new belt. 11 don't have a temp gauge.

I'll say it: head gasket.

Made in Mexico

>I'll say it: head gasket.
Please stop with the meme of saying "head gasket" for every problem. It's an old meme and should be retired now. Find a new meme.

Those are signs of a head gasket failure user, sorry but that's what it sounds like to me too.