exhaust leak under power only

[schyawn]

very odd situation. I smell exhaust while driving on the highway above 75mph, but not below. This is with the windows open. Close the windows and can't smell it. It also smells when i accelerate harder than normal. I've tried to find the leak by getting under the car, no leak or smell found at idle. Had a buddy rev the engine for a while, no leak or smell at all then either. Also checked under the hood at the manifold, nothing.

It's pretty aggravating that i'm breathing exhaust when the engine is worked hard, but not otherwise, because it's very difficult to find the leak:( Short of putting the car up on a dyno, which i have no access to. Have any of you experienced anything like this???? I can feel my brain deteriorating from the fumes!

I've replaced all gaskets recently (last month), except the manifold gasket. Was thinking about doing that too, but I don't want to do it, and then still have the same leak.

[ADAMHU]

yeah my turbo car is a pig for leaks....i basically just leave it until i can't stand it anymore..then replace the exhaust manifold gasket..or the turbo gasket..or the wastegate gasket...which ever one it is ...

[cpuls]

I'm having lots of exhaust problems on my turbo KA as well. First go-round I pulled everything apart and found that my Rev Hard manifold was warped almost beyond belief (1/8" off of flat!). I put it on a belt sander for about 45 minutes to get it flat again. I also had warpage on my turbo flange. After putting it all back together it ran great on the road/daily driving. But then at my last track event (Texas World Speedway - 8 sessions of 25 minutes each at max power) - the leaks came back!!!!

The biggest problem seems to be the manifold to wastegate gasket and the bolts backing out. But again I have leaks between the turbo and manifold and the manifold and head. Arghh!!! I guess I'm going to try to flatten it all out again, put in new gaskets and this time use some safety wire to keep the bolts from backing out.

[TomsMR2]

best way to hunt down leaks is by ear.. they make a funny sound, like a swooshing, or distinct ticking sound. listen for ticks or the leaky swoosh, then try to feel around for the exact location. my leaks go inaudiable when i rev, so i check at idle.