The Combine Forum banner

Stuck exhaust manifold.

15K views 50 replies 25 participants last post by  aussie farmer 
#1 ·
2390 we have needs new exhaust gaskets, no big deal I figure, take the manifold off, put new gaskets on and problem solved. Only trouble is I can't get the manifold off. Either all the holes in the manifold have swelled or all the studs have swelled, or someone put a crap ton of loctite on the manifold studs cause I had to heat the nuts up red hot to get them to move( see attached). I've soaked it with wd40 several times a day for the last 10 days and been carefully hitting it with a hammer and a 2x4. I called a local engine rebuiler and he suggested I keep doing what I am only to heat the ear of the manifold to the point of where it is just barely red then leaving it to cool a bit then spraying wd40 on it. When I am heating it there appears to be oil boiling out of the hole but I assume that what I am seeing is the wd40 mixed with dirt or something.
Anyone have any tricks? Other then wailing on it with a sledge till the manifold shatters into several pieces.
 

Attachments

See less See more
3
#3 ·
Try heating the stud itself until its red hot. Go away and had a few beers, play with the wife or something long enough to let it cool.

I've had a bit of luck that way, it gets the stud hot to expand breaking the corrosion then when it cools the part slips off like a prom dress.

Actual results may differ.
 
#4 ·
My advice is to take a pair of new nuts if there is room otherwise one. Get it on the stud till they are flush. Take a shaft and a hammer and lightly tap several times and then take a blow gun and blow around the stud.

Tapping on the studs will do two things, it will help lossen them from the manifold but also the threads. Chances are they will need to be replaced given how they look so you will want to get them ready to come out.

Chances are your really lucky because I could almost guarantee they would have twisted off otherwise.

I think Captain USA is correct but I would use that last if at all possible.

You should be able to beat on the manifold pretty good with a good deadblow without doing damage to it. I don't mean go nuts on it but it can take a pretty good hit that way. I would also consider laying a block of wood against it for beating on.

Good luck!
I mean it to cause your going to need it!
 
#6 · (Edited)
Here's a good one, I tried it today We had a stuck dipstick tube nut and I think it helped, also tried it on a couple ujoint yolks on a shaft, heated them, added wax, went for lunch and they moved amazingly easy.

No guarantees though :D

Good luck.

PS, I discovered this in Whtbaron's thread "Rusty threads".
 
#7 ·
An air hammer is your friend. I'd try using the air hammer on the ends of the studs, one after the other. If you aren't good with a welder the head may have to come off to remove the studs. If you aren't ready to go that far if necessary, leave it as is.
 
#8 ·
I see your problem, first of all you are supposed to break all the studs off flush with the head. This way the manifold falls right off. Then you just have to worry about drilling out the broken studs. This is where an e-z out really shines! E-z outs work best with a slightly beat up cressent wrench that keeps working loose. When the e-z out breaks off inside the hole, this is where you start to realize that the little exhaust leak wasn't maybe so bad.
 
#13 ·
kevlar;2769521this is where you start to realize that the little exhaust leak wasn't maybe so bad.[/QUOTE said:
I know most people are not aware of this but exhaust leaks are huge performance killers on turbo charged engines. It is very common that once the air filter becomes plugged and the engine is asked to run at full load they will score pistons, blow holes in pistons or burn valves.

Yep, just some little exhaust leak can ruin your engine.

I actually am speaking from experience on that one, noticed the leak the morning of the last day of harvest. Just shrugged it off and said that will be fun to fix, ran it with little thought, burned a hole in a piston.
 
#19 ·
Ha, I've got you beat! Twice for me! I was so surprised it actually worked I took a picture of it! I would post it but the pic is on the phone I ran over last fall.:52: Pretty sad when something like that is picture worthy!
 
#16 ·
IF an EZ out breaks flush try to find an edm (electrical discharge machine) shop to remove the ez out out of the head. I haven't had the priviledge but at the manufacturing shops I worked at that's what they would do to save the part (if worth it) when a tap or drill bit broke in the component.
 
#17 ·
Easy outside can and do work. First buy straight spline ones. Then drill the right size hole tighter isn't always better as it swells the bolt.tighter . Next heat the bolt with a torch. If you get it to move work it back and forth while spraying with a good penetrating oil. Wd40 is not a good lubricant pb blaster jb 80 or kroil is better.
 
#21 ·
Thats some serious corrosion between stud and manifold , patients is the only way without destroying something ,
plenty of wd 40 and swap it with inox and other types .
The key is to heat each peace seperately and try to rapid cool each piece seperatly , its the difference in heating and cooling speeds that will break it free , after a week or two of trying that i would be temted to drive it and give it some hard work with nuts just on end of thread.
If that fails maybe a hole saw that fits over stud without a drill bit in it .
You could also try blocking other end of manifold and attaching aircompressor then heat and cool with intermittent bashing with hammer.
 
  • Like
Reactions: daneg
#25 ·
I like the idea of putting the nuts back on so the manifold won't fall right off and driving it -- also the air hammer on the flanges -- but small short vibrations seemed to work the best rather than a big wallop from a hammer . Good luck with the studs after getting the manifold off but a stud into a block will usually come out fairly easy . A stud remover with a cam or wedge type of grabbing system would be my choice to remove studs as you are using all the stud's circumference not just two sides like when using a pipe wrench .
 
#28 ·
Heat is the answer, your pics look pretty bad. Heat the flange around stud till it starts to glow. let cool right down. Also as mentioned use the air hammer to shake things up and break out that rust. Beating with a hammer breaks things. Not sure if sprays do a whole lot till there's a bit of wiggle, maybe something like deep creep would get in there and do some work. WD 40 isn't that great of a penetrating oil in my experience. Once you get manifold off I agree with welding a nut onto the stud if they don't want to come out. One old guy I worked with showed me a trick when a stud breaks off flush. He would get a washer slightly smaller than stud, weld washer to stud then weld a nut to washer. Seems to work well, maybe you get more heat deeper down, little safer too so you don't weld stud to head as easy. Neverseeze the studs when you install your new one so this doesn't happen again.
 
#29 ·
Just an update. Still haven't got it off, found out the centre part of the manifold(crotch part) was cracked. Got the water manifold off finally, I don't think this thing has ever been apart. The only studs that aren't free are the top ones on holes 4 and 5. But they are moving so I am winning. Haven't hit it with a 10 lb sledge yet.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top