Check your throttle body (may be dirty), TPS and IAC.

 

Help - I decided to change my thermostat. One of the bolts on the housing was somewhat tight. It moved a couple revolutions fine but then became tough. I carefully went back and forth over and over trying to get it out. Then it did break. I have almost 1/2" of the bolt exposed. What is the best way to try and remove? I tried get a couple nuts on the end to try the "double nut" method to try and get a socket on it but I can't get a nut threaded on. Am I best just to grab the thing with a pair of vice grips or is there anything else I could try first?

 

You can try the vice-grip method, yes. You can also take a dremel or whatever, and grind a slot into the sticky-outy part, and use an impact screwdriver to try and work it out. Before you do ANYthing, though, appy some penetrating oil of your choice, and let it sit for a day or so, then apply it again, let it sit, and so forth. You can also try heating the bolt with a map gas torch. Watch out for setting fire to an oil in the vicinity!

Hope you get it soon! I always use antisieze compound on bolts like that. Just a thought...
Pat☺

 

Thanks for the advice. Yes, rather than try anything immediately I have doused in some liquid wrench. As you suggest, I will give it a few doses through tomorrow. When you say impact screwdriver are you meaning one of those ones you hit with a hammer? What about one of those bolt extractor bits where you drill a skinny hole into the bolt and insert the bit (which grabs) - i could see the shaft of that breaking as well though. I just have a reg propane torch - maybe not as hot as the map one - but maybe worth a try. After several hours and a few applications of liquid wrench and wd 40 I tried putting a pair of vice grips on the bolt stud. It won't move yet. I will continue to let it sit/soak.

 

Spot weld a nut to the top of it... the heat will likely make it almost hand tight...
it's a fool proof method to remove busted exhaust manifold bolts

 

i might consider that but no welder

 

On the impact screwdriver, yes, that's what I mean. Heavy, metal handle, most have interchangeable bits. Sometimes a few good whacks on that with a BFH will do wonders.
Did you try turning the vice grips both ways> that ensures the oils get worked down into the threads.

Yes, an Easy-Out might work, but remember, that they are brittle. Hard, to go into the hole you drilled and bit into the metal there, but their hardness means they're brittle. Be SURE if you use one that you don't apply any side forces to it at ALL. If it breaks, you're just back where you started. At least you're no worse off

Good luck! Worst comes to worst, drill the hole, including the bolt, out. Then you can either put in a Thread-Zert, or use a tap to re-thread it. You do it that way, make sure you make note of the size of the tap you select, so you can get the right sized bolt to go in the new bolt-hole.

Have fun!
Pat☺

 

No, you're much worse off. Your "next" step (as you point out) would be to drill out the bolt. You're not going to be able to drill through an "EZ-out." They're much harder than a drill bit. (There is a type of EDM machine used solely to remove broken taps and EZ-outs. You don't have one.)

For me, I only use an EZ-out if the bolt broke because of impact. If the bolt was rusted in so well that I broke it with a wrench, I'm pretty sure that it will have no trouble breaking an EZ-out.

One method not yet mentioned is a left-hand drill bit. You use a reversible drill motor, and the torque of the drill bit is in the direction that would drive the bolt out. As you get near the tap size of the bolt, the reduced amount of metal remaining might let the bolt start to turn, and back right out.

 

So with the impact screwdriver I would first have to cut a slot or something in the top of bolt - I don't really have anything for that other than say a hacksaw blade. Then of course would have to also find one of those impact screwdrivers. I did try moving either way with the vice grips - no luck. I should have been able to move it in a bit I would that thought because it was turning about 1 -2 revs before it broke. I will try again tomorrow.

 

would a left hand drill bit be similar to the bolt extractor?

 

Put the vice grips on the remaining stub as tight as you can possibly get it, and use one that is thin enough to leave the top of the stub exposed... it maybe a smaller vice grip than you'd normally use... but, get a good grip and put some torque on the bolt while tapping on the top of it, progressively getting more torque and harder taps.... go both directions.

 

I will give that a try. i do have a pair of those long nose/smaller vice grips - not as much strength as the full size but should allow me to tap on top of bolt. I tried just a while ago with my reg vice grips. You may know that this bolt is a little tough to get to - basically, have to come straight down with the reg pliers. I couldn't get it to budge either way. I threw a little heat on the surrounding metal with a reg propane torch. I thought I would be able to turn it in a bit but it won't move (because I did get it rotated back and forth at least 1 full revolution before it broke). I will try the tapping method this evening. I did put some more penetrating oil on.

 

No luck on getting that broken bolt out yet. Have been putting penetrating oil on it for last 2 days. i also tried applying some heat with my regular propane torch - but I don't really think it is getting it that hot. It is also darn near impossible to get a vice grip on it horizontally because of the tight quarters. Mostly I grab it vertically with the vice grips which isn't the best for leverage. Tonight I took a 1/2" socket, applied some ultra grey to the bottom rim of it and set it over the bolt. After it set I filled the socket with penetrating oil so that this thing can soak in it. Maybe that will make a difference - not holding out much hope because that bolt although sticking out 3/8" is so stuck there. I'm not sure how that is because these bolts aren't torqued that tight.

 

might be time to take off the upper plenum, so you can get at it better. perhaps remove the lower plenum, too (with the t-stat boss), and do it on a bench.

 

More heat. Be patient, heat it for several minutes. Map gas is better than propane, oxy/acetylene is better than map gas.
got any spare parts? You could forget about it and swap in a different manifold.

 

Should I be throwing the heat on the surrounding area or directly on the bolt itself

 

the surrounding area.

 

It's not because of torque, it's because of corrosion... it's stuck. Heat and vibration are what's going to get it out. It would really help you to get a nut welded to the top of it so you can turn and tap at the same time.

 

applied 7-10 mins heat from propane torch. got vice grips on horizontally but very very little swing room. managed to move the bolt - it took me no fewer than a dozen or so clampings onto the bolt to make 3/4 of a revolution. the bolt is tight the whole way - its not like it just breaks loose. almost as if it is crossthreaded in there. Anyways, made it to about 1 revolution and didn't want to move again. threw on some more heat for 10 mins. not sure how long this bolt will last with the vice grips going on/off and twisting -its thickness starting to reduce.

 

If it’s going to break anyhow, cut it off with a grinder, drill it out, tap and replace it with a slightly larger bolt. It’s just a bolt. The engine will not know the difference.