Considering X-Pipe and Dumping Test Pipes Questions (AE Exhaust)

[cjm41]

I'm running AE exhaust with Macht Schnell test pipes. I can find little to no info about the exhaust, but my car sounds deep and very bassy, like set off car alarms at idle bassy, and I love it.

Since I bought my car two months ago I swore I had an exhaust leak. Two shops insisted I didn't. A third shop (the best shop I've been to and my new go-to) installed a new driveshaft almost two weeks ago and mentioned a couple issues with the exhaust and that there was cause to believe there was some minor leaks. They mentioned these fitment issues could be solved by going with a full x-pipe.

When they put everything back together the exhaust leak was gone, but it's redeveloped again and it's infuriating to me. I'm super sensitive to exhaust leaks.

So question is... do put a full x-pipe on the car or weld the test pipes on.

I do love the sound of the car. I'm okay with it being louder but I don't want to lose the unique bass-y, muscle car sound. Emissions isn't a concern.

I don't want to spend a lot and be unhappy. And since there is so little info on my axle back (AE) it's hard to get much info/advice on which x pipe would be best (there's YouTube videos for every other combo).

Grr. Anyone selling a reasonably priced x-pipe? General thoughts on killing the exhaust leak otherwise?

[kevin @ eas]

AE was one of the louder exhausts on the market. No longer being made so that probably the lack of information out there. Test pipes are more prone to leaking due to their clamp on design. X-pipes would be a better option for someone more sensitive to leaks. Also an x-pipe will delete the secondary cat with add a few more hp. I'd look at the Macht Schnell x-pipe for a replacement, very reasonable cost. Feel free to PM me for details.

[amrazM]

Get a quality resonated x pipe, get something with four resonators you won’t regret it.

[cjm41]

Originally Posted by kevin @ eas

AE was one of the louder exhausts on the market. No longer being made so that probably the lack of information out there. Test pipes are more prone to leaking due to their clamp on design. X-pipes would be a better option for someone more sensitive to leaks. Also an x-pipe will delete the secondary cat with add a few more hp. I'd look at the Macht Schnell x-pipe for a replacement, very reasonable cost. Feel free to PM me for details.

Originally Posted by amrazM

Get a quality resonated x pipe, get something with four resonators you won't regret it.

Thanks guys. I may poke around the interwebs for 30 days or so looking for a used x-pipe.

@kevin would the Macht Schnell x pipe make the car a bit louder since its deleting the second set of cats? (I'm okay with loud- I prefer loud, wondering if there might be a louder option) I probably just missed some solid Black Friday and Cyber Monday deals.

I appreciate the response, Kevin. If I shop new x-pipes I'll give you first dibs on my money

[kevin @ eas]

Originally Posted by cjm41

Thanks guys. I may poke around the interwebs for 30 days or so looking for a used x-pipe.

@kevin would the Macht Schnell x pipe make the car a bit louder since its deleting the second set of cats? (I'm okay with loud- I prefer loud, wondering if there might be a louder option) I probably just missed some solid Black Friday and Cyber Monday deals.

I appreciate the response, Kevin. If I shop new x-pipes I'll give you first dibs on my money

It will increase sound levels since the secondary cats are being deleted. Secondaries arent a huge restriction but do choke down sound and a few hp.

[Iyzmi]

I had a small exhaust leak around one of my clamps so had my mechanic weld the test pipes for $250. I don't want to run catless and this route is much cheaper than a HFC X-pipe for basically the same result.

[cjm41]

After spending another $350 today I still have an exhaust leak, and I'm just about over it. The car. All together.

The 4th shop the car has been to I basically went in and told them what to do. I wanted my stupid garbage Macht Schnell test pipes welded to the stock midpipe because, quite frankly, x-pipes seem to be a massive rip off after a lot of research.

Now...

Shop 4: I walk into and tell them I want to weld the test pipes to the midpipe, essentially creating a full 1-piece x-pipe. The secondary cats are retained to reduce drone all the while keeping a solid x pipe the M Division engineered. I also brought new gaskets from BMW so when they bolted it back up to the headers we'd be in decent shape.

Nope.

It definitely sounds better, but I'm confident exhaust is still escaping from somewhere else around the front/mid area of the car.

I was around a bunch of other M3s the other day from stock to supercharged, none of them had my exhaust leak sound.

I've been building engines since I was a kid, no I'm not mistaking that light BMW valve tap sound for an exhaust leak. Unfortunately I don't have a lift and the car is low, so getting under it in a parking lot is tricky.

The only place it could be is where the headers/exhaust manifolds meet the head, or where the mid-pipe (now one piece with the test pipes) meet the axleback exhaust. There are new gaskets between the headers and the test pipes (now one piece with the test pipes).

I'm almost on the verge of selling an otherwise nice car. I'm so discouraged I'm about to put a cover on it and forget about it for a while.

So with the issue with the test pipe and mid pipe connection being a non-issue now, does anyone have any ideas?

[BayE30]

Should have went with an X-pipe. your time is worth more than whatever you saved. get the car up on jack stands and get underneath it while running, you will find your leak. If your car is too low to jack up and get under, then who cares, you already ruined it.

[cjm41]

Originally Posted by SFCM3

Should have went with an X-pipe. your time is worth more than whatever you saved. get the car up on jack stands and get underneath it while running, you will find your leak.

I bought the car with the test pipes. If I were plotting this out from the beginning maybe I'd have chosen an x pipe, but at least I didn't spent $1200 on an x-pipe to find out that wasn't the issue this time. I'd be furious. Right now I'm just feeling defeated.

I had plans tonight and cancelled them because I literally don't want to drive the car, for the first time since buying it.

[wfdeacon88]

does the leak sound go away after warm? or is this a permanent leak you hear..? I've read on here that most of these cars stock or whatever sound like they have a leak at the headers, but it goes away and isn't an issue. just a thought

[cjm41]

Originally Posted by wfdeacon88

does the leak sound go away after warm? or is this a permanent leak you hear..? I've read on here that most of these cars stock or whatever sound like they have a leak at the headers, but it goes away and isn't an issue. just a thought

It's pretty noticeable during cold start but quiets down after. When the car warms up it's less noticeable but I can hear it when it's running next to a wall or next to other cars in at a stop light.

It's completely unnoticeable with the windows up... but it's winter in Florida so it's windows down time.

I've got a couple of go pros (well, fake go pros) I just bought maybe I'll go outside and see if I can get some video.

I was inspired by your rod bearing post where you said a lot of little weird sounds went away when you changed the motor mounts... But i know I'm getting my hopes up- this is def an exhaust thing.

[EnVe46]

Originally Posted by cjm41

It's pretty noticeable during cold start but quiets down after. When the car warms up it's less noticeable but I can hear it when it's running next to a wall or next to other cars in at a stop light.

It's completely unnoticeable with the windows up... but it's winter in Florida so it's windows down time.

I've got a couple of go pros (well, fake go pros) I just bought maybe I'll go outside and see if I can get some video.

I was inspired by your rod bearing post where you said a lot of little weird sounds went away when you changed the motor mounts... But i know I'm getting my hopes up- this is def an exhaust thing.

Don't sell the car for a shitty set of test pipes or a shitty seal somewhere in the exhaust! I know this shit can get real frustrating but once you get this figured out, you'll love everything your M makes.

My suggestion, find a used full xpipe that has resonators in it, there a few on this forum alone and get t swapped it. Eliminate the current x pipe completely from the equation.

[tdott]

Ask a shop to put it on a lift and look for leaks.

If you were close by I'd tell you to bring it over and we can check it out.

[cjm41]

Originally Posted by EnVe46

Don't sell the car for a shitty set of test pipes or a shitty seal somewhere in the exhaust! I know this shit can get real frustrating but once you get this figured out, you'll love everything your M makes.

My suggestion, find a used full xpipe that has resonators in it, there a few on this forum alone and get t swapped it. Eliminate the current x pipe completely from the equation.

As frustrated as I am I'm not ready to take a $5k bath on something I've had for two months, I was being dramatic, but I don't want to drive it.

Aside from this it's an excellent car. Great shape, runs strong, it's exciting to drive.

The whole $1000 for some steel tubing that is literally no better than the stock x-pipe, seems like total BS, especially when full x-pipes for non M-cars are like $300.

I believe I've eliminated the test/x-pipe issue and the sound isn't loud enough to be a header gasket issue. It's got to be coming from where the mid/x-pipe mates to the AE axleback exhaust.

Aside from the exhaust leak I love the sound of the car and I'm getting almost all the power I can out of the exhaust (aside from killing the second set of cats for 4-5 hp). So spend up to $4,000 (x pipe plus new axle back setup) to have a car that makes the same power and probably sounds not as good (except for the fact the exhaust leak is gone) sounds like a lot of BS to me.

Maybe a custom exhaust type shop? I find it hard to believe I've got to live with a minor exhaust leak or spend thousands of dollars.

[amrazM]

Custom fab work done correctly isn’t cheap, buy a Borla X pipe. Reasonably priced and the quality of it is very good, it’s a slip section in the middle no flanges like some of the other x pipes on the market.