2014, Is it the Water Pump Casing? (Broken bolt installing new thermostat)

[rooksstrife]

I literally checked every car part place you can think of from Autozone to Rockauto - none of the thermostats they sell have the gasket. Called the Mitsubishi dealer = have it with gasket for $35. I'll pay that for piece of mind :]

So the whole endeavor was to get the heat working. I really think it's the heater core, but after doing some laser heat readings I started thinking stuck open thermostat even though a code wasn't showing. Either way I was like easy enough swap the thermostat, flush the radiator, and then back flush the heater core... and we all know how that went blaaahahaha

[Dirk Diggler]

I literally checked every car part place you can think of from Autozone to Rockauto - none of the thermostats they sell have the gasket. Called the Mitsubishi dealer = have it with gasket for $35. I'll pay that for piece of mind :]

So the whole endeavor was to get the heat working. I really think it's the heater core, but after doing some laser heat readings I started thinking stuck open thermostat even though a code wasn't showing. Either way I was like easy enough swap the thermostat, flush the radiator, and then back flush the heater core... and we all know how that went blaaahahaha

Wow Mitsubishi actually had a part that wasn't marked up 3000%? I'm shocked OP. That's the Achilles's heal of the Mirage, finding aftermarket parts. This shocks me considering Mitsubishi has sold what? 200k Mirages in North America since 2014? That's plenty of units to have at least some sort of aftermarket system set up IMO.

[Dirk Diggler]

I also agree with Fummins that if you get the bolt out properly, the thermostat gasket which presses on the inner part of the opening should seal it properly. Good luck!
I didn't want to frighten anybody, just don't McGyver it, do it properly instead.

I think its just a cultural thing. What's the old saying, "In England, they'll lie to your face but be polite. In Germany, they'll be honest with you but be a dick about it."

[Top_Fuel]

...I really think it's the heater core...

Go to this post and read the PDF attached. This explains how to identify if your Mirage has a restricted heater core (without reading through 300 posts).

The good news is that people on this forum have had some success with flushing out the heater core with stronger materials. In other words, something like Prestone Super-Flush will not clean the gunk out of your heater core.

[rooksstrife]

So here are the original symptoms. Fan motor 100% (which works) full hot on the blend, after driving for like an hour engine is at 179 per OBD reader | driver vent is 115 (feels like luke warm to hand) | passenger vent is 64 | top radiator hose is 150 | both heater core hoses are about 126 | Lower radiator hose is 120 | direct engine laser read 167 | foggy windows, but not too bad as I've seen before with heater cores. I thought heater core 90% with a possible stuck open thermostat.

[CROSSBOLT]

Everyone has to start somewhere. I was a machinist's apprentice when in highschool so got some training there. Restored a Model A Ford in highschool, too and learned loads about stuck, stripped and broken bolts, easyouts and new, really bad words. The most disgusting learning is when you must retrain when you booger something because you weren't as careful as you were when first learning. Rephrase that with you had your head up your a$$. You is to be taken rhetorically, 'cause I'm talkin' about ME!

Hey! Just because you have landed a plane over 12000 times does not mean you are mistake-proof. You have to do it by the steps EVERY time. Where is the checklist....? Them's who have and them's who gonna...

[Top_Fuel]

So here are the original symptoms.
...engine is at 179
...driver vent is 115
...passenger vent is 64

Well...sounds like your thermostat could have been an issue. But you also have the text-book symptoms of a partially restricted Mirage heater core. So you might gain a little heat output from the thermostat change if it was faulty...but your primary heat problem is almost certainly a gunked up heater core.

So get ready for phase 2 of this repair job when you get the thermostat back in.

[7milesout]

but it beats me how an adult can do something like that.

I've worked on many a car. Brand new, before brand new, used, well used. I've done quite a bit a stuff. I'm meticulous and thorough. I have torque wrenches and a fairly thorough selection of tools. Yet I can f up some crap like that at any time. I applaud the OP for doing it on his own, and working to find a solution to what has happened.

I'm watching, but don't have any good solutions to offer. Working with a machine shop of some kind sounds like something to check into. Those machine shop guys are quite professional and have done a lot of "stuff."

[Fummins]

I literally checked every car part place you can think of from Autozone to Rockauto - none of the thermostats they sell have the gasket. Called the Mitsubishi dealer = have it with gasket for $35. I'll pay that for piece of mind :]

So the whole endeavor was to get the heat working. I really think it's the heater core, but after doing some laser heat readings I started thinking stuck open thermostat even though a code wasn't showing. Either way I was like easy enough swap the thermostat, flush the radiator, and then back flush the heater core... and we all know how that went blaaahahaha

At least there's now an easy way to replace the heater core without removing the entire dash and draining the ac.

[rooksstrife]

At least there's now an easy way to replace the heater core without removing the entire dash and draining the ac.

Go on about this new black magic you speak of...what is this new way without ripping out the dash?