I'm suspecting a small leak on my 03 Navigator that seals quickly in a minute after starting. How easy or bad it is to replace the exhaust manifold on an Intech 32v V8 (not a Triton) ?

 

Which side?

 

both, I'm thinking that engine needs to be pulled up because of the shock tower.

 

The passenger side is the easier of the two. Remove the wheel and wheel well liner for easier access to the manifold. Once the manifold is out inspect the tranny dipstick tube for signs of perforation.

For the drivers side, again remove the wheel and wheel well liner for easier access to the manifold. This side is harder because the oil dipstick tube, the steering shaft, and the EGR tube are in your way.

 

I thought I had that issue on my 03. When I crawled under it i notice one of the bolts where the 2 meet before the muffler had some out and was sounding a lot like the manifold. put a new bolt in and solved it. Maybe worth checking that first.

 

I did check those already and even replaced the gasket prior to the muffler. I tried smoke test to check the leak but it doesn't work, can't find any that I know of. I suspect that it maybe because of the aftermarket muffler but I kind of suspecting an exhaust leak on the manifold because it ticks like for 10 secs on startup and goes away, step on the throttle and exhaust is loud.