Possible exhaust leak

sunwolf

New member
Since I installed my LME catted downpipes about 1 year ago I had a sound under partial load that has been driving me crazy but LME assured me was normal. Recently it got much worse and sounds, to me, like an exhaust leak. I just ordered a used corsa catback which I plan to install next weekend and I was thinking about taking off the downpipes, inspecting them for leaks, and replacing the gaskets to see if that fixes the problem. The noise is noticeable at idle, gets worse when put into gear, and is terrible when brake boosting to ~1500 rpm. I had someone brake boost it while I watched the pipes and the entire exhaust drops quite a bit but the flex tubing on the passenger side vibrates a lot more than the driver side. When brake boosting I also see some smoke coming out of the exhaust. Do you think this could be the turbo seals going bad? Can I inspect the seals when I remove the downpipes and what should I look for? Also has anyone ever had the flex tubing leak on LME downpipes?
 
Usually a leak is a matter of doublegasketing the downpipes with new OEM gaskets, and periodically torquing them to spec.  Smoke is what color - black, blue, white, a mix?  I assume blue since you are worried about turbo seals.  Does it keep pouring out or it is just a puff and then gone?  Have you inspected hoses on the top end to see if any have popped off or split?  Checked turbo piping and intercooler for oil pooling?
 
If there is a leak on the pipes, put  some  high temp rtv on the gasket, tighten it and let it sit over night to dry.
 
SHOdded said:
Usually a leak is a matter of doublegasketing the downpipes with new OEM gaskets, and periodically torquing them to spec.  Smoke is what color - black, blue, white, a mix?  I assume blue since you are worried about turbo seals.  Does it keep pouring out or it is just a puff and then gone?  Have you inspected hoses on the top end to see if any have popped off or split?  Checked turbo piping and intercooler for oil pooling?
Smoke is blue and it comes out fairly steady when brake boosting. Hoses have popped off before but I clamped them back down so they don't come loose anymore. Turbo piping has always had a little puddle of oil in it which two dealerships have said is "normal" so I assume it isnt much more than anyone else. Haven't checked the intercooler in awhile so I should do that.
 
SHOdded said:
Don't know if the valve cover is the updated one on your SHO, or if this TSB 15-0086 might still apply:
http://www.ecoboostperformanceforum.com/index.php/topic,3836.msg78980.html#msg78980

But when talking to the dealer, say your turbos are leaking oil, don't mention valve cover, unless they are a "friendly" dealer.  Better chances of warranty coverage.  Are you under 3/36 still?
They are a friendly dealer. I'm at 46k and it is a 2014 with build date some time in February.
 
Mike check to see if there is any signs of H20 on the ground by the Flange area and twards the front of the car preferably on a cold morning start with the car idling for ten min,if so you have an air leak.
 
I checked the throttle body and it was dry so there isn't really that much oil in the lines. I also pushed on the downpipes right at the catback connection while the car was running and found that when pushing on the passenger side in one direction the sound gets worse and the other way must close the leak because the sound goes away.
 
It sounds like they are pretty loose,probably need to retorque those bolts to roughly 100lbs of torque,did they tighten the bolts by hand?  Z
 
And a new double gasket. The motion likely ruined the on on your car. When I installed my DPs we put a screwdriver between them to tighten the bolts on the flange. It made the whole system hang vertically on the rubber hangers near the 3rd cat.
 
I had my brother Rev the car so I could get a better look at the smoke and it looks more white. I will see if I can upload a video tomorrow but what does white smoke mean?
 
Water in the system somewhere.  Usually happens in humid conditions or after car has been sitting long enough for moisture to condense inside the exhaust system.  Should disappear fairly quickly.  A continued outpouring of white smoke would not be good, as that means there is water inside the engine that is exiting in a vapor/steam state, meaning most likely a water pump, head gasket or turbo jacketing leak.
 
I finally got around to installing the Corsa exhaust yesterday and I took a look at the downpipes. Exhaust was leaking at the flex pipe and the gaskets. There was a crack in the right flex pipe. I already called LME and they said they stand by their products and will replace it. Here is a picture although it is kinda hard to see.
 
SHOdded said:
Very cool!  Hope you can put this saga permanently behind you now :thumb:
Hopefully. On a side note do the turbos usually scream when you do catback and downpipes? Now they almost sound like a slipping belt when I really get on it.
 
They shouldn't, esp not with the LME exhaust components.  If the sound is coming from the turbos, you may have a lubrication/cooling issue or a leaky seal issue.  Recently had someone suffer a broken turbine shaft on their front turbo, so should not ignore it.  If the sound is coming from the BOV (have you done this mod?), that may be the tune.  Which version do you have, V8/V9/V10?  What oil/filter are you running?
 
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