I can't figure out where my exhaust leak is coming from. I replaced both exhaust manifold gaskets (all four) and both exhaust manifold to pipe gaskets and it's still leaking out from somewhere, but where?

It's quite at idle but under acceleration it sounds like crap.

I try to listen while driving next to walls or medians and I think its coming from the front of the truck. Hence, the idea to replace all the exhaust gaskets.

Any ideas?

 

SeaFoam induction cleaning. Watch the pipes to see where the smoke is leaking from.

 

Good idea, thanks. I will try it.

 

Or crawl under and look for the tell tail grey/black soot stain.

 

I tried that, Mike and nothing sticks out.

Could it possibly be the SAI system? I checked for any damage to the pipe that connects to the manifold, but did see anything.

 

did you ever resolve this? I am having a similar issue and I believe it is coming from the SAI tube front plug on the pass side. I'm also wondering if this is causing my CEL to come on triggering codes for all four O2 sensors

 

Don't look just at joints and flanges. Could be a crack in an exhaust manifold. Might be hard to see around things like the starter/heatshield.

 

You can take a light piece of paper, tissue, etc... and tape it on a pencil or pen, like a flag. Move it around the system and see where it moves the most....

 

I know that the SAI system is well known for having leaks, usually they sound like a tick coming from inside the engine but, tighten the fittings and it goes away. Good Luck, hopefully that's all it is. A manifold is probably WAY more expensive than turning a wrench!!!

 

I'm resurrecting this thread back from the archives. My exhaust leak has gotten worse. Never took any action to fix it.

I read on here that the unions (on the block side of the SAI tube) that hold the SAI tubes to the head sometimes work loose. To tighten you need an 18mm crows foot on the union and either adj pliers or a large open-end wrench (not sure of size) on the large SAI tube nut.

Will try this soon. I think both sides are leaking. It sounds horrendous.