Tale of how I won the exhaust manifold.
99% of Saturn Vue owners with a 2.2 liter engine experience exhaust manifold cracking. Usually everything happens like this: first, the rightmost pin is torn, then the next one after it, and then the collector itself bursts in the middle. This is usually accompanied by a farting sound and twitching of the car. There is an opinion that all this begins with a clogged catalyst.
I didn't notice the crack right away. I didn’t have much sound, but the smell of exhaust was coming into the cabin when parking with the engine running. There were also failures when starting from a place.
Upon closer inspection, I saw a crack in the exhaust manifold. Also torn pins.
Then it was decided to brew on their own. I read literature. I drilled holes, cut a seam with a grinder, took electrodes for cast iron, cooked for half a day, when it cooled, the seam vomited. I couldn’t brew it myself, I thought to fix it with a patch and an asbestos cord, cut the seam again with a grinder, laid asbestos, cut the thread, put on the patch, it turned out even worse than it was (farting sound, smoke, and big engine jerks.
It was decided to take it to specialists, I looked for such a long time, read reviews, found it, brewed it in 15 minutes, without any drilling and furnaces, their device is the size of a small refrigerator.
The plane led. The middle is bent away from the motor by 2 mm. It had to be milled.
After spending 3 days of time and knocking down thresholds, I did not find specialists in our city. Some impotent. Give everyone a direct and small collector, they say we can’t clamp your ...
It was decided to cut himself.
I bought large sheets of sandpaper 300 and 800, pasted it on the table top, fastened the top of the collector to the drawers with an elastic band so that it would evenly stand up without distortions to the sandpaper, and drove with water to grind in 8 figurative movements.
I didn’t bring it out ideally, of course, there was half a millimeter or less left, I was tired, I decided it would do.
Between the two middle legs on the platforms, the thermal gap disappeared after welding. I cut it with a grinder again.
Now you need to make studs otherwise it will tear again. I bought a new gasket, plasticine, a large syringe, soda and nitric acid of chemical purity (it contains the largest% of acid). See photo. I made grooves from pieces of a bottle and plasticine, diluted the acid with water 1 to 1 and poured this mixture into the grooves (without dilution with water, the steel is oxidized and covered with a film, as a result of which it stops pickling). I changed the mixture about every 3 hours except at night. Given the temperature outside, about 12-15 degrees, I poisoned 2 hairpins at the same time for 4 days.
Take care of your hands, I burned mine by negligence a little. Also do all the procedures on the street, as acid fumes are very harmful.
After pickling, we treat everything with a soda solution to neutralize the acid. Studs fit From many cars, including Russians. To install the manifold, I used wide washers and brass nuts instead of native steel ones, smeared all the threads with copper grease before that.
Tightened like a spiral. Starting from the extreme pins to the center. That is, 4 cylinders then 1 then 3 then 2, in several passes. Do not rip off the brass nuts, they are softer than steel.
Good luck to all!
Stud breakage is one of the most common defects that a motorist may encounter. Studs are used in many vehicle components. But if you do not have a car, then this does not mean that you will never get into this situation, because the bolt can also break.
The way to extract the debris, which I will show, it seems to me, is one of the simplest and most effective. It will fit even when the chip is 2-4 mm deep inside.
Removing the pin piece
So let's get started. To begin with, we measure the diameter of the stud by its fragment remaining outside. In my case, it is 8 mm in diameter.
We take a wooden block, and stick 3 layers of masking tape on top of it. Then we make a hole in all three layers with a diameter smaller by one millimeter.
Cut out an arbitrary contour. And we got such a gasket.
We stick it on the hole with a fragment of the stud. This gasket will protect the threads during welding.
Next, you need to take any L-shaped steel corner with a thickness of 2-5 mm. And drill a hole 7 mm in diameter in it.
On the reverse side, use a large drill to make a hole for the cone.
We put the corner on the hole and fix it with pieces of masking tape so that it does not fall during welding.
The holes must match exactly.
welding time. It is advisable to use a semi-automatic welding machine. Well, if not, take the usual one, with a thin electrode.
First, we deposit a layer on the chip.
This is what it looks like after the first time. Let's wait a bit.
We put on another layer for reliability.
Well, now, you can try to unscrew the hairpin.
Everything turned out great. Welding warmed up the chip and it became easier to unscrew.
This is what it looks like up close.
Installing a new pin
As you can see, neither the thread nor the area around, nothing was damaged after welding. We sand the area with sandpaper. IMPORTANT!: I never etched the hairpin, due to "suddenly" revealed circumstances.
In the post, I decided to share my experience: why you may fail when you take on this business and how to make your life easier if the stars are favorable to you.
Since the time is late, and today I was terribly fucked with this hairpin, I will try to be short and to the point.
Background: I have a Suzuki SV650. Not on the move - there is no chain, many nodes are in varying degrees of disassembly. The motorcycle has an L-shaped two-cylinder engine (V-shaped with a camber of 90 degrees).
Due to the fact that I have an awl in a soft spot and I can’t sit still, I decided to unscrew the exhaust pipe mounting bolts in order to remove it. Why I will not describe not about this post. Three bolts with mats came out, and one soured tightly ... DIRECTLY DEADLY. What I just didn’t water him as soon as I didn’t persuade him, but at the next jerk he broke off. There was a small piece left to stick out.
First: if you have such a problem, do not rush to drill.
If the place allows, try to weld a nut and unscrew it, it helps a lot, I haven’t tried it, because I don’t have a welding machine, I don’t have friends, no one in the area knows how to cook, and yes, in garages, some fans stand to look at the car with a serious view.
Second: if a welding machine is for you, this is an egg boiler, then try to take a thin drill, very thin and drill 2-3 holes in a row in the stud so that you can drive a slotted screwdriver into them (or rather a head with such a screwdriver) and try to screw it all up. I learned this method too late, when there was already one big hole in my hairpin, but everything could have ended so quickly and simply.
Then you can continue the list of methods such as extractors and similar devilry, but I won’t, since all this is only suitable for a simply broken bolt in pure metal or wood.
And I have a tightly stuck M8 bolter in the front cylinder - in a terribly uncomfortable place.
This is where the juice itself begins, as they say.
Attention! Hero of the story. The one below.
He's full face. 
At first, fishing rods were thrown here, on the forum in the sense. I got a lot of advice from the guys, but they almost all boiled down to removing the head and transporting it to the nearest turner or repair plant or turning plant ... I still didn’t understand where I should look for them and most importantly, how can I get the turner there to help me with something, he does not stand in front of the gate with a sign I will waste dviglo. Since for me, in general, removing the head is too much ... since I’m not a corny mechanic, I don’t know the internals, there’s nothing to jack the engine and there are many more reasons “against”, I decided to use the last available anemic method - etching the bolt with acid, nitric HNO3 if I don’t have memory changes.
We climb on the Internet where we subtract that nitric acid dissolves most metals with the exception of gold, stainless steel, platinum group metals, a couple more metals rarely found in the hands of the layman and, most importantly, aluminum from which the engine is made.
That is, if you pour an iron bolt into aluminum can nitric acid, then the bolt will gobble up, and the can will remain intact.
For all this bacchanalia, I needed:
Nitric acid. I live in Moscow, where everything you can buy is concentrated, and what you can’t, you just need to look a little longer. I found it at our chemical store. If you are not from Moscow or St. Petersburg, you need to look for it either in the same stores or at chemical plants.
Since this reagent is very harmful, I needed thick rubber gloves, mask, which has been replaced with a paint job respirator (better than nothing) and protective glasses, they are sure, but the acid did not get on them, but there were splashes a couple of times when manipulating the reagents.
Plasticine, he doesn't care about acid, he molded a funnel from it over a hairpin. Soda- an aqueous solution of soda serves as an acid neutralizer, but their reaction is very violent, from which the splashes described above were caused. A couple of syringes. A couple of containers (jars bottles). Water is normal. Aluminum foil - to protect surrounding places and parts of the motorcycle.
So, everything is there. A few words about the already mentioned acid. The main thing to remember is safety. A broken bolt is nothing compared to chemical burns of the skin and mucous membranes. Acid, even diluted, is toxic, even without reacting it floats - it releases caustic volatile substances. When interacting with dissolved metals, the reaction is very violent with the release of heat. During the neutralization reaction with soda, nitric oxide 2 is released, which is very toxic + intense seething occurs and if such a reaction occurs in a bottle, a “fountain” is possible. Do not work indoors.
Let's continue about the frivolous. With the effort of the fingers, this miracle was done. 
Funnel for acid. At the end of it is a stud drilled with a drill 6.
After reading information on the Internet, I found out that acid in the initial concentration sold in stores ~ 67% can enter into an act of love with aluminum, but diluted to 30% (as well as pure 90%) passivates aluminum, that is, does not react.
Dilute the water with acid. That's right, and not vice versa - pour acid into water as taught in chemistry class. Otherwise, it may splatter.
They mixed it, shook it up a little, took it into a syringe and poured it into an impromptu plasticine bath.
And they went off to drink tea with milk for a while.
Come - WOW! The carving is clean as ... clean in general. There are no hairpins, you can add cognac to tea, although it’s probably rubbish with milk.
…
I also thought it would.
He came, looked, and there, as it was quiet and smooth, it remained, the aluminum of the engine was intact, the hairpin was also nothing like that.
Maybe I think the weak acid turned out very well, they say, I overdiluted it. I went and took the first bolt I came across from the box and threw it into a bottle of dilute acid, from which I only filled the syringe. Twenty minutes later, the bolt was gone, leaving a slight haze behind. And there is silence...
You probably, like me, did not read this sentence very carefully, a little higher: with the exception of gold, STAINLESS STEEL, platinum group metals, a couple more metals that are rarely found in the hands of the layman and, most importantly, aluminum.
Mdya hairpin bitch turned out to be stainless steel, kind former owner American. In general, I filled everything with a solution of soda - plasticine and the remains of 30% acid in the bottle, for which I received a fountain of reactions and wandered home sad.
Outcome: Check what broke off. Indeed, a 30% solution of nitric acid dissolves metal like hello, if it is not aluminum and stainless steel. You won’t have time to blink and there are no hairpins. And if you have broken off an ordinary cheap bolt in aluminum or stainless steel, then this method is very effective and cheap, and most importantly, not very labor-intensive. The budget is about 1000 maximum including everything (protection, acid, accessories). Time 1-1.5 hours.
That's all. Good luck to all. Take care of yourself.
