Thanks for the info!

[D'Animal]

After reading this thread https://forum.ih8mud.com/showthread.php?p=2629925#post2629925 and the great info posted up, I decided it was time to fix the exhaust leak on my FJ40.

It was missing one of the exhaust studs. I bought a new 10x1.25mm x 60mm stud and the exhaust donut.

I found the exhaust downpipe was cracked 1/2 way around right below the flange. I removed the entire exhaust system so I could weld it up properly. The crack was in the engine side.


I welded it up and reinstalled it along with the new stud.

Here is the old donut.

 

[D'Animal]

I assembled everything but still had the major exhaust leak.

After closer examination, I found the intake/exhaust gasket was blown.

I took the intake and exhaust manifold off and found this.

 

[D'Animal]

So I clean up the head and the mainfolds and assemble the engine completely.

I start it up and still have a major exhaust leak, no change in the sound at all. WTF!

I take everything back a part and find this.

 

[D'Animal]

I had to travel all the way across my shop to grab some OEM gaskets. LOL!

I cleaned the mating surfaces and checked them for trueness and put this assembly together kind loose. I will tighten it down after it is installed on the head.



I don't know why, but I blame/thank Cruiser Drew. He owes me a friday night. If he had not posted in the other thread about this I would have put off the repair for another year. I never would have known how bad everything was.

 

[D'Animal]

Put it all together for the fourth time and I still have a slight leak between the manifolds and head.

Time to double gasket.

 

[nat]

Fun work

Do you have a good straight edge? Are your manifolds very warped?

 

[kellyo]

Man, what a pain in the ass. These things are so much fun sometimes. Good luck with it.

 

[greenfox]

That's the first place I look Dan next time you will check that first

 

[D'Animal]

That's the first place I look Dan next time you will check that first

LOL!

Check what first?

 

[D'Animal]

Fun work

Do you have a good straight edge? Are your manifolds very warped?

Well lets just say that I've had an exhaust leak for so long that the exhaust manifold is worn where is was leaking.

If this was my DD I would have had it machined. I have another 2F I going through right now that will replace this one. I will do the swap in the "Off Season".

 

[Colorado Boy-74-FJ40]

That's exactly how mine looked. and when I took my manifold off I found the down-pipe was cracked 3/4 around the pipe just below the donut. It was about ready to fall off, that's how bad it was leaking. I would recommend to everyone running a stock F or 2 F to take a good look at their exhaust, it may be in pretty bad shape.

 

[D'Animal]

Original.

New Gasket after taking it apart 4 times and still having a leak.

Another new gasket.

Wife asking why didn't Toyota put wing nuts on it since it has to be taken apart so many times = Priceless.

 

[fjatheart]

Original.

New Gasket after taking it apart 4 times and still having a leak.

Another new gasket.

Wife asking why didn't Toyota put wing nuts on it since it has to be taken apart so many times = Priceless.

Did you use permatex at all?

 

[Poser]

Get the manifolds resurfaced where it seals to the head and you will not need to stack gaskets.

 

[nuclearlemon]

moral of the story....
never start a project because it just snowballs

 

[65swb45]

Wife asking why didn't Toyota put wing nuts on it since it has to be taken apart so many times = Priceless.

Best laugh of the evening there Dan!

Can't tell from the photo if the ex mani is a single piece or three piece setup. If it's a 3 piece, it shouldn't be too hard to get the center section cleaned up with a file to sealable condition. If it's a single piece, I'd think about replacing it anyways.

Milling really is the best solution.

Best

Mark A.

 

[Spud]

D'Animal...Did it seal up after installing the 2nd gasket?

I am having the same issue. Pulled mine all apart and replaced the gasket, I did file it a bit and reinstalled, also used copper coat on both sides of the gasket. All back together to find I still have exhaust leaks and Vaccumm leak!

So I was thinking of the dbl gasket...Did it work out for you? Did you also have vaccumm leak issues?

When inspecting my manifold, it appeared as though one section of the intake stepped down from the adjasent exhauset manifold section. Looks to drop down about 1.5/2mm. Then step back up for the next section. Is this typical of how they "warp"...Anyone? In the 2F motor manual the spec says OK for up to 2mm of warp.

Pulling it apart....Again.

 

[D'Animal]

I took it all apart and fixed a few other things as well as installed all the smog stuff.

The double gasket did work for a short period of time.

 

[Spud]

I took it all apart and fixed a few other things as well as installed all the smog stuff.

The double gasket did work for a short period of time.

Short period of time eh'...
So what is your next plan...machine it? Or live with it?

Do you have vaccumm leaks due to the manifold?

I ordered a wingnut kit...Ha Ha.

 

[D'Animal]

Short period of time eh'...
So what is your next plan...machine it? Or live with it?

Do you have vaccumm leaks due to the manifold?

It sealed up and worked great for a few months.

I began having other problems so I had to take it back apart. The EGR block off plate came loose. I found a plug in the manifold that had a hole in it, etc. I think we found 9 areas that had leaks.

I removed the Holley Carburetor and went back to the stock carb and emmission stuff. I don't have it all back together yet so I cannot tell you how it runs.