4.0L rusted upper intake stud/nut

I’ll be needing to remove the upper intake manifold soon in order to replace the driver side valve cover. In prepping for this the front stud/nut is very rusted, like in the yellow circle of this picture. There is also one in the rear that is not all rusted. Anyway, I’ve been soaking the front stud/nut with ATF to “hopefully” being able to remove it without snapping it. If it does snap, for those that have encountered the same problem on the same stud/nut, what did you do to remove what was left? I do have new studs on hand from Toyota just in case, will pick up some nuts as they don’t come with the studs.
Thanks

 

Not sure how ATF works, but I would just soak it with penetrating oil. I don't recommend heating since the intake is plastic.

I wouldn't be too concerned if you round off the bolt. Worse case you hammer on a smaller socket and then try to remove it. There are only 3 outcomes. 1) You get the bolt off, 2) The bolt and the stud come off together, 3) You break the stud. I don't see the 3rd option happening. Even it it does, you will be able to remove it from the intake manifold later.

 

Living in the rust belt, I have personally worked on and seen many, many fasteners in far worse shape than that one come right off. Keep soaking it with penetrating oil or ATF with a solvent and I think you'll be just fine. Just be gentle when you start trying to turn it and if it feels like it's stiffening up as you go, reverse direction for a bit, then go back to loosening. Working it back and forth will prevent you from breaking something off 90% of the time.

 

Brake fluid also works wonders. Don't get it on any painted surfaces however.

 

After soaking for a bit, can you hit it with an impact wrench? Sometimes the jolt can be enough to break it free.

Good Luck.

 

Kroil Oil. Yes it's expensive. Yes it's worth it.
Also, the intake bolt is a stud, so if the nut is seized on the post, the entire stud should unthread before it breaks.

 

There’s been some great suggestions already. I’ll add a few.

Using atf is better than nothing or something less effective like cooking oil. If you use a penetrant designed as a penetrant, you’ll have better results. Pb blaster is a favorite, liquid wrench is very powerful but nasty stuff so use precautions to keep it out of your eyes and away from the kids.

Repeated application, drive to warm it up, toothbrush wire brush to get it thoroughly worked in and cleaned off.

Use a 6 point wrench so you can see what it’s doing. If you watch closely, you’ll see if the nut is moving away from the stud, or the stud is moving with the nut.

An impact could be good or bad. It might just snap off, or round off the nut, or break the nut loose of the stud. An alternative would be to put your 6 point wrench on, a little lefty pressure, then tap on the wrench to cause percussion. The percussion shocks could cause it to break free.

Another trick I’ve found that works really good is to put your wrench or ratchet on, then tie a string to it to hold loosening pressure on it. Leave it like that occasionally checking the tension on the string, tug on it, make it tighter if needed, leave it.

If it snaps off, hopefully some stud is left sticking out of the mating surface. If not start hunting for a friend who’s good at extracting, hopefully someone with patience. Not the dude who’s every story has “and then I got mad” in the middle of it.

 

Keep soaking it and I would definitely hit it with a small wire brush. Get those threads as clean as you can before you start.

 

Thanks everyone

 

I wouldn’t put brake fluid on that. I’ve seen brake fluid destroy certain kinds of plastics before.

 

Wasn’t planning on it

 

Acetone and ATF are life changers, unless youve some Rost off maxx ice around

 

u need this

https://www.google.com/search?q=bol...ome..69i57.2564j0j15&sourceid=chrome&ie=UTF-8

 

id be a bit worried to use one of these around the plastic intake, but these are magical, been looking at getting one to help rebuild my 67f100

 

Some bolt busters have a different orientation & you would need to come from the side or from straight above. They will certainly melt some plastic!!! My brother wants one for his birthday but fuck are they pricey!

 

Kroil for a couple of days and a bit of heat from a induction heater. It'll pop right off. Don't overheat it, you want just enough heat to draw the Kroil down into the threads. Pop it with an impact on low, you want to shock it, not break it. Replace the nut, do NOT reuse it.

 

It’s a nut on a stud.
It could be worse.
Spray it with oil, take a steel brush and clean the threads best you can.
Then try to remove it.

Don’t sweat it, worst case the stud comes out with it.
That’s better than a broken bolt.

 

Exactly, spray it, let it soak, send it.

I don't think this would break. If it does, easy fix.

 

Just wanted to provide a final update. With all the soaking of that nut/stud they were still rusted together enough that when I attempted to loosen it the stud came out with the nut. No problem as I had a new stud and nut on hand for replacement. I was able to get them apart on the bench.
As a bonus.....here are some pics of under the valve covers and of the lower intake manifold. The cam lobes were smooth/looked good. I was not happy with the amount of carbon build-up/crud but I believe that is due to two things. 10,000 mile oil changes for most of its life and 494,000 miles. I switched back to 5000 mile oil changes about a year ago for my own sanity. Also, kind of hard to see inside the runners of the lower intake manifold but the crud you see is mostly oil residue from the PCV system as I wiped out each runner and they became mostly clean/looked like clean aluminum again.

 

seeing some of that crap build up. think i may install a catch can under the hood.