broken thermostat bolt

A mechanic has a big mental tool bag of skills. You need to use AI to get a list of the possible methods. Problem is you haven't the muscle memory of any of these skills and you don't have the tools.


Solutions:
1. Electromagnetic induction heater: Magnetic Induction Heater Bolt Removal https://a.co/d/0ZqvJ1Y

2. Weld a nut onto it and use that plus heat

3. Use grinding wheel to grind bolt flat and used hi carbon steel bits purchase anywhere except harbor freight after using a center punch to drill into that bolt with left-handed drill bits and then an easy out

4. Cut a piece of aluminum off and TIG weld in other piece of aluminum on drill it and start over

 

Eric the car guy weighs in:

 

You are now entering very dangerous territory. Safety is paramount. Please protect your precious organs. You can always buy another Prius, your eyes is another story. I know you know this already, but it helps to have someone else restate it for you.

 

I don't want to be a debbie downer, but I have a bad feeling you're about to wreck this thing. There comes a time when you fold your cards and seek experienced help. F this up and there's no easy or inexpensive next try. I have yet to break a bolt on a Gen 2. Although I have no idea what you may have spent for an amazon welder, it's likely more than it would have cost to have a pro get it out. I wish you the best of luck.

Quick edit.....I am wrong about one thing for sure. I just looked up welders on Amazon...never realized anyone could sell a "3 in 1" welder for 80 bucks. Bet it's a champ, but definitely cheaper than a pro mech or mobile mech..at least in the short term.

 

I agree with Hayslayer. It might even be worth having a reputed mobile mechanic come to you.

 

Well reputable mobile meccie . I'd rather play around on my own dime an expert isnt going to make lotsa difference . He wouldn'tve broken the mess. Toyoda bolts aren't brittle . Good rule on old stuff . Tighten one click first. Then reverse out by hand . Don't always reach for automatic tooling.

 

Yes, but you play with cars all day long. Not the guy who is in a bind. As much as I hate taking my car to a mechanic, I would not hesitate to do so for certain things.

 

Perhaps you only see those people......
As a technician.... I've NEVER seen a car fall on someone.
Busted knuckles is #1.....

I hope your welding works. Perhaps an inductive heater would work better?
Make sure you clean the area of any oils that could catch fire.....


As a long term RN, the #1 way people get seriously injured working on cars is having the car fall on them

 

It's obvious you know what you are doing. Let us know how it goes.

 

For insurance, getting under a car, if it's possible (and it usually is), I push this under first:

 

I like to get it on jack stands at the pinch welds and then I place my floor jack on the front lift point, raised just enough so it makes contact and lock it. Catastrophic failure at 3 points is pretty unlikely.

 

I use alternates to the pinch welds, see oil change link in my signature. (on a phone turn it landscape to see signatures)

Food for thought: if you put the scissor jack at the "pinch weld" location, and start it up, you'll see it's not actually the pinch weld that's bearing on the scissor jack; the jack cradle has a notch that cups around the pinch weld, and the bearing point is on the inside, beyond that vertical seam, just the regular car body sheet metal. And that point dimples in with even one use, as I found, using it just on a rear corner (with a flat, out and about).

Decent pic of the front points I'm using here (in those pics I'm still using pinch welds for the rears, but I've long since stopped doing that as well), and on page 2 of that there's mention of the alternate rear points I'm using. The latter are basically on the humps where the locator pins are during shipping, where you see those oblongs slots with rubber plugs.

 

The problem with beginner welding is you could permanently fuse the bolt into the timing chain cover or melt the aluminum. You have already stated access is difficult.

The advantage an experienced auto shop has is they have plans a-z to get it out, have the best tools, muscle memory based on years of experience and a high likelyhood an easier method like acetylene heating and specific tools will get it out in ten minutes.

 

When you throw in the towel and are at a point where a shop can't get it out, you can change the timing chain cover (removal needed for a head gasket job) or get a replacement engine, especially if yours is burning oil.

A JDM engine replacement would be my choice for value (almost equal to a shop's head gasket job) with no extra cost added for a timing chain cover (maybe $200 on ebay).

Your engine's thermostat mount


A good cover and thermostat housing


My takeaway is don't replace the thermostat unless it has failed based on measurements. Absolutely as last resort if other bolts are rusted.