Leaking exhaust manifold - anyone had luck welding them up on the vehicle?

[jiggletits]

I fully understand the best thing to do is remove these, and replace them... or weld them off the car. However;

I have a small MIG welder. I have two GX's both with leaking manifolds. I do not have patience to pull them both off without trying this first. Also not interested in the DT headers.

Anyone had any luck with this? Clean metal makes for the best weld... but I have had pin-holes welded up on s***ty, rotted out pipes at least half a dozen times on older vehicles and they held up fine without having removed the pipe, cleaned the metal, all that fun stuff that makes for pretty welds.

Has anyone tried this with any luck?

Thanks,

 

[Rednexus]

I think it would be very difficult. The manifolds have a tube at each cylinder and a flange that slides over it. The tube is flared at the end (where it seals on the gasket) and cracks at the flare. The flare is totally under the flange. Exhaust gasses escape at the tube/flange gap. So you would need to completely fill in the gap between the tube and flange, in an extremely tight area. It will still leak unless it is filled. I do not think you will have access for a MIG gun with the manifolds on the vehicle.

If you were willing to pull the manifolds off you could weld them at the actual cracks and reinstall. It would still be a day or two of work unless your fasteners are in perfect shape.

 

[jiggletits]

Gotcha, makes sense. Thanks for explaining. I haven't even pulled the heat shields to look at one yet.

The nuts/bolts on my CA/CO 2003 with 270k come off wayyyy easier than the nuts/bolts on my 2006 that spent some time in NY. Rust crust is the worst. Maybe I'll start with the 03.

 

[Rednexus]

It was a nighmare job for me, read my build thread on it. Mainly due to one bolt stripping (middle, lower bolt on both sides). For the reinstall I ended up making some custom sockets by cutting down deep ones to the perfect length that still allowed a string of U-joints and wobble extensions to fit. Your reinstall will be easier using OEM manifolds instead of headers, but I'd still plan on replacing most of the studs and nuts with OEM Toyota parts. Also, Fel Pro manifold gaskets are exactly the same as OEM and half the price - made in Japan too.