Hey,
Just wondering how many MAC shorty header owners experience this problem - with the leaking driver's side collector.

I'm wondering if there's a lot of you guys out there - because I've had 2 sets of MAC shorties, and both of them experienced this *same* problem - the driver's side collector leaks where it meets the y-pipe, and all the tightening of the bolts won't fix it - because the y-pipe seems to mate with the collector's ball flange at an incorrect angle.

With 2 different sets on my car (I've had mac headers before.. took them off because they leaked, then 6 months later decided to try again with a new set) - the problems are the same. the hissing under load from the collector leak, poor low end performance from the messed up af ratios...

if any of you guys had this problem, how did you all fix it? Suggestions/tips would be appreciated.

thanks

 

I had my pipes off this weekend for a plug and wire change and noticed that the pipe didn't fit up right the first time I went to put it back on. I loosened the Y-pipe all around and twisted and held it in the right spot and tightened it all up. No problems before, no problems now. Good luck.

 

TTT for you.

 

Hey if you figure out the answer I would really like to know as well because I hate driving my car sounding like this

Rich T

 

Have you e-mailed them, www.macperformance.com , and seen what they say???? I think its from being mass produced and their QC isnt catching the defect, maybe??

93Z Will

 

Just do what i did...


Buy long tubes...

Problem solved

 

Eh, I live in CA I'd love longtubes, they sound sweet and I love that "whoosh" sound the longtubes make - but yeah.. being a poor college student in CA really sucks.

I'll email MAC and see what they say. I'll post their response, if there are enough of you following this thread and wondering the same thing.

cheers,

 

ive installed 3 sets without any problems. loosen everything up, and retighten carefully..

 

my slp's didnt fit quite perfect on the driverside header to ypipe flange either.. I put a bunch of red rtv on the gasket and around the flange. it stopped the leak for 3 or 4 months.

 

Are you sure it's an exhaust leak? Do you hear the sound at idle, feel the leak or see carbon deposits at the leak site? I ask this because I noticed a "flutter" sound (possibly your hissing) on acceleration. Couple of other members have reported a similar sound. Possibly due to valvetrain noise and/or exhaust gas hitting the thin primaries.

It is annoying. Feel free to send me a message if your successfully stop the noise.

Michael

 

hey michael -

Yeah, I have that fluttering sound, which used to be *very* loud - but got much quieter after I tightened my spark plugs. However, on top of that, there is a loud "hissing" sound, matching with rpms.

I'm sure this is the exhaust leak - because when I look at where the ypipe meets the driver's side header, I see an area where its black with carbon

 

If anyone has heard anything or found a fix for this type of thing, let us know. I have Arizona S&M's and I have the same problem-bad fit at the collector.

 

I've got MAC headers and I have never liked how the driver's side collector mated to the y-pipe. I dont have a leak or at least not loud if I do but it just looks really wrong.

Let us know if you find anything out.

 

well, i e-mailed MAC about a week ago, but I haven't heard *anything* from them. bastards...

I unbolted the headers, just let them hang loose.. then bolted up the ypipe tight, before tightening the header bolts.

The leak is mostly gone (I still *slightly* hear it under hard throttle), and the ypipe is still crooken on it.. damn.

I've heard this can result from maybe from worn/sagging motormounts... hmmm. For those of you with the collector not fitting right - does your steering shaft/knuckle also rub along your primaries?

 

I found the problem! No help to MAC though, they haven't even replied to any of my emails (up yours, MAC).

My problem was worn motor mounts - my ypipe rested against the crossmember and couldn't fit over the collector right because the motor was sagging down too low. I took out my old rubber engine mounts (92k miles on them), and they were sagging at least half an inch on each side.

Give that a check! I haven't put my old ypipe back on yet but I'm 95% sure this is the problem.