Busted Thermostat Mount
 

I was changing the thermostat on my blazer this afternoon, and all as going well until the last two bolts. The bolt closest to the air intake decide it would rather die then come out, so die it did. The threaded portion snapped in two leaving about one centimeter sticking out above the thermostat housing, not near enough to grab with pliers.

I have currently left the car in the Autozone parking lot since it was getting cold and a winter storm was starting up. I have very little idea on what to do. I have put everything back together except that bolt and it is not making a good enough seal to keep coolant in. I have not turned on the car yet, but I can freely wiggle the top of the thermostat housing.

So far me and a few friends have come up with 3 attack plans:

A) Use a liquid weld with almost 6,000 psi tensile strength and try to fix the bolt by welding the two end back together and then pulling it out with the ratchet again.

B) Tow it home and disassemble the air intake and throttle body, then drill out the remaining bolt.

C) Just say F**k it and use the same liquid weld from "A" to seal the thermostat in forever.

I really don't want to do C... Any other ideas or advice?

A. Is going to make a mess- and not work.

C. ....well I'm going to pretend like I didn't read that one

B. Is going to be the way to go. Once you get the thermostat housing off and out of the way, you may have enough meat to grab the bolt with a pair of vice grips.

If not, try and find a buddy with a welder to weld a nut on the broken bolt so you can just back it out with a socket. This is usually the easiest and most effective way, the heat from the weld helps break the threads loose.

If that's not an option, grind the broken bolt flat and drill/tap it for a new bolt.

None of my friends here have a welder sadly otherwise I probably would of done that.

By grind it down and tap it do you mean to basically to drill a hole into the bolt and then screw in a new bolt within the stuck bolt, or am I miss reading this?

It is kinda on an angle for the break and I believe some of the bolt is below the hole. Does it need to be perfectly flat, since I doubt I can grind the small bit no longer above the hole.

I can tell you that there isn't enough meat left for vice grips to work.

The guy at Autozone said in order to get a drill bit to the bolt I'd need to remove the throttle body and the air intake. Can I do that in the snow (worried about snow getting into the air intake)?

I kinda need to get this done by Friday...

Currently the winds are hollowing mighty fierce and the forecast has nothing but snow for the next 10 days. Figures my car breaks down in this.

Kinda just came to mind, but can that lower part of the housing that the thermostat sits in be replaced?

Idk why you'd need to remove the throttle body. Intake yes, but throttle body shouldn't be in the way.

Either way, yes you can remove it, just cover the throttle body or hole in the intake manifold with plastic as soon as you open it up. You're going to want it covered anyway so you dont get metal shavings in it.

You're going to want to make an 1/8th inch hole right in the center of the broken bolt. Then gradually step it bigger until you're a couple sizes smaller then the bolt. Then run a tap(same size as original bolt) which should make your threads and shread the last lil bit of the broken bolt out

I know how to get the black cover off, but how do I remove the big silvery thing (yes I know I used "thing")? Or can I just get a very long drill bit set somewhere, I can't recall I've ever seen one though.

I vote for B.

Could you not use one of these bolt extractor kits? https://www.autozone.com/test-scan-a...set/466512_0_0

Otherwise you might be stuck using a Heli-coil fix. A possible problem that would concern me would be if it is hard to drill out the bolt and because it is harder than the surrounding material, say if the intake is aluminum, then the drill bit would shift and go into the surrounding metal.

I had one tow from AAA so I decided to just send to a shop instead and they said it would be 1-2 hours for $70 an hour. They called me today saying they couldn't get it out by the welding method (they are not going to charge me for these 2 hours).

Now they are giving me 2 options:

A) Replace lower intake manifold 4.5 hours + parts (it is still snowing here and in single digits, so I definitely can't do it.)

B) Tap out bolt, they said it would be 3+ hours

Which should I do? I'm kinda leaning towards just replacing lower intake since they are a common thing to go and I have been loosing coolant...

I would go with A so that you have the upgraded, metal carrier, Fel-Pro LIM gaskets installed. (Fel-Pro p/n MS-98002T) Although I'd be a bit concerned if any damage has already happened if your coolant losses have been very much.

Perhaps someone else can chime in on how to know if an internal leak at the LIM has caused any damage yet?

When I did my LIM gaskets I took me several hours each day over a period of a few days to do it all. I'm no the fastest worker but I would think $150-$200 in labor would have been money well spent. Just be sure to have the proper upgraded gaskets installed.