MmMmmM Donut..

[awthorn]

So I have had an exhaust leak since we dropped the new engine in the truck. I checked all piping and well it was good to go. So i figured it to be the exhaust manifold, egr or donuts.

:help:

Got all the gaskets (OEM) and replaced them and the leak still exists. I think it is coming from the rear most donut. If i place a piece of paper behind it I can feel it vibrating when my wife presses on the gas. Anyone have any advice for these? Should I remove the bolts where the downpipe meets the header again and re-tighten? Thanks!

 

[awthorn]

So, i could not wait until tomorrow. I dropped the down pipe until i could see the little donuts sitting there with probably enough clearance to change them. Then i proceeded to tighten them down in a circle, there are three, to make sure i was applying even pressure. I then torqued them to 25 foot pounds.

STILL have a leak.. what the heck mate!? Any advice would be greatly appreciated!

 

[1985taylor1925]

Misleading thread. I was expecting to see donuts. Now I want donuts and I don't have any in my house. Im so glad that Hostess came back

 

[BrianSD_42]

mmmmmmm donuts


lane:

 

[awthorn]

[MENTION=56756]1985taylor1925[/MENTION] and [MENTION=65101]BrianSD_42[/MENTION] no advice? Lol

 

[papapoopski]

 

[IBallEngineer]

Any possibility you deformed the flange the donut aligns with? It is pretty strong, but once bent it won't retake the shape by tightening against the donut. Also, can you tighten it without the donut to make sure it does go far enough to seal? I grasping for straws here, but I HATE exhaust leaks.

:fro:

 

[Harleydoc]

Is it a new donut??? Sometimes if they have been used they will not seal I would see if you can get a new one and make sure you get the right sized one some of them as small and some are big

 

[T4rUT]

I HATE exhaust leaks.

:fro:

Once had a small leak on my 3VZFE donut in the flange where the downpipe connects right by the bell housing that could barely be heard. It pointed right at the transmission and was small at first so I let it go until it got bad enough, started seeing the A/T oil temp light! Damn rusted exhaust bolts always snap too.

 

[awthorn]

[MENTION=102597]IBallEngineer[/MENTION] I don't think the flange is deformed. Although i cannot see the back side like I can the side/ front. But that sis just remind me I have a bore scope I could use to look at the back side.
[MENTION=81049]Harleydoc[/MENTION] yepp there are two new donuts and a new manifold gasket from Toyota. The fitment around the flanged lip was good. I also cleaned all the services with a brass brush and some carb cleaner. To make sure the mating surfaces were good.

 

[awthorn]

Ladies and gentelmen, without further adieu. The results of the bore scope.



Now what do i do? Do i just torque the heck out of the bolts to close it up? They are already at torqued to spec at 25 ft pounds.

 

[1985taylor1925]

[MENTION=56756]1985taylor1925[/MENTION] and [MENTION=65101]BrianSD_42[/MENTION] no advice? Lol

No, sorry. I don't know anything about this issues. I do however want a sugar glazed from Duncan Donuts. But we don't have Duncan here, so Im still at a loss