What is the best way to determine where an exhuast leak if coming from? I went NS on my turbos this winter and everything is boosting well and running great except I have a little tick, tick, tick coming from the hotside of the engine bay. I know i heard this initially when I first fired the car up so I figure it may be 1 stud not fully tightened to spec as the sound definitely is sourced from the turbo area. It can also be heard on my dyno video, but disappears as I hit Higher RPMS.

I am going to tear into the hotside one more time this week to see if I can determine where this is coming from and was curious if you guys have any tips for determining where an exhaust leak origniates from before I tear into it one more time. Will there be visible signs as I take things off where the leak is coming from?

 

Exhaust leaks are my worst enemy and because the turbos are torqued pretty low it's wise to replace the gaskets and studs but they are pricey so if you think yours still look really good you may get away with it atleast in the short run. However after already bolting them up and getting an exhaust leak I'd advise on getting atleast new gaskets. BTW I probably have a new turbo gasket set laying around so I'll check it out and if you need a set give me a pm.

It's sounds a little weird but some folks advise on using a long feather to find the leak hehe but you can use a piece of paper etc....just don't catch anything on fire

 

Yep, it's just tricky to find a leak.

My low-tech method is to put the car on jackstands when it's bone cold, start the car, and use my hand to feel around the flanges. You can easily feel an exhaust leak, even a small one. Of course, you have to work pretty quickly before things heat up too much.

Also, many thin-wall stainless downpipes will have a "tink" sound to them that sounds like a slight exhaust leak. No way around that, ceramic coating doesn't help that either. I believe mild steel downpipes are better in that regard.

Dale

 

I like the feather Idea. Before I tear everything apart I think I will put the car up on stands and see what I get. It may very well be the downpipe, but i need to get in there for sure.

Funny thing is I used new gaskets pretty much everywhere...

 

i put seafoam in my car and watch the smoke pour out of all my leaks.

 

I was just thinking about that idea.

I recall being told to spray soapy water to find the leaks - that's a bad idea on a car with an exhaust this hot. Especially when you're looking up at the exhaust from underneath.

Take care that aftermarket exhaust components usually have poor flange flatness. THe stock 2-bolt design is just awful for making a gasket seal which makes it that much worse.

Also, if you re-use your stock hardware with the nut fused to the stud, it's ok buy only if the nut bottoms out before the threaded end of the stud. I would add a washer under the nut if you re-use your stock hardware for that reason.

 

the trick is to pressurize the exhaust system from the muffler using a shop vacuum /leaf blower/etc. this will force air upstream. using a soapy water solution, spray all the mating surfaces. the bubbles will appear, similar to finding a leak in a tire

 

couldn't pressuring your exhaust potentially cause damage to the engine?

 

I dropped the cash on new studs from the engine to the downpipe with new Mazda Nuts, so they shouldn't be fused together and I think I wil be ok here.

I have some seafoam..... If I remember correctly, I feed this through the UIM ?

 

don't some shops shoot smoke up the exhaust system to check for leaks?


Seafoam freaks me out. I wouldn't ever use it. Just my phobia.

EDIT: They do.

http://www.youtube.com/watch?v=ISWtCKHl0YE

 

Feather/paper trick worked pretty well... looks like (with out being underneathe the car, it is the turbo to manifold gasket. I used Pineapple Racing Graphite Gaskets, but torqued them to stock spec... I think I remember reading that they need a lil more torque due to being graphite.

I am a pro at taking these turbos on and off now

 

this is rather old..but im replacing the manifold to turbo and turbo to manifold gaskets..and its a pain in the ***. i've ogtten it down to the turbos, heat shield, and trying to get the exhaust pipe off the turbos, busted a bolt, and one stud is too long so the pipe wont come off without hitting the steering rod...any references onto how to remove and install stock turbos for the sakes of changing out gaskets? pm me please