Exhaust Leak (close to the engine)

[radiod]

I heard a little bit of a ticking noise when I was around 0 vac/boost on acceleration one day, so I spent a while trying to track it down. After youtubing/googling and searching around I'm pretty sure it's the sound of a tiny exhaust leak closer to the engine. So I went ahead and checked as many nuts/bolts that I could on my exhaust manifold/turbo/downpipe that I could reach at the moment and found one on the exhaust manifold that had backed off a tiny bit, but other than that it was all tight.

It's hard to pinpoint because the only time that you can really hear it is if it's at 0 or pushing a tiny bit of boost. If you blip the throttle at idle from in the engine bay you can get a small glimpse of it but not for long enough before engine/turbo/exhaust noise drowns it out. Anyone know of way I can try and track down where it might be coming from?

The other possibility I came up with is I do have a divorced down pipe. Could this just be the flange between the waste gate and the rest of the exhaust leaking a bit?

 

[StrikeIS]

Check the egr cooler. its on the back of the head, near the firewall. I had this problem and it was coming from there.

 

[radiod]

It doesn't sound like it, it sounds more like exhaust manifold side of the engine rather than behind, but I'll definitely check it out. I sure hope not....that would be a major PITA to get to with the engine in the car :3d_frown:

 

[StrikeIS]

yeah its not fun. ratchet wrenches are your friend with this job. lol. I thought mine was coming from the manifold as well. I even went as far as replacing the manifold and turbo gaskets and having the manifold milled at a machine shop and it was still doing it till I fould the bottom of the egr was leaking. Not a fun day.

 

[radiod]

What's the easiest way to check/confirm where the leak is coming from?

 

[Nick M]

When the Toyota donut goes bad, they have a put put put sound that isn't very loud. The studs don't have to be loose to have the leak.

 

[mkiiichip]

What's the easiest way to check/confirm where the leak is coming from?

Smoke it.
http://www.redlinedetection.com/p-13-smoke-pro-total-tech-w-standard-accessory-kit.aspx
You said easiest, i know its not the cheapest alternative. But any reputable shop will have one of these and diagnosis will be about an hour or less. May be easier than pulling your hair out.

Also a divorced DP (on a internally gated turbo) is just a giant exhaust leak.

 

[radiod]

How would you hook up the smoke for testing exhaust leak? Only time I've used them has been at my old job to try and find leaks in the evap system on vehicles, so hooking it up to the gas tank. I guess you could try and hook it up to the tip and seal around it but with a divorced downpipe all the smoke pressure will come out there, am I not correct?

I know a divorced downpipe would leak, but would it be able to cause the ticking noise I described?

 

[mkiiichip]

Yeah id just hook it up to the divorced DP, then if you find no leaks, you know that the DP is the noise your hearing.

Or plug it while cold, and see if and see if you can still get the same noise while "bliping" the throttle.