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Discussion Starter #1
After a track day this weekend, I started getting a puttering sound under acceleration on the driver's side. I'm thinking it's an exhaust leak of some sort. It sounds like a single cylinder, as opposed to multi-cylinder post-cat. No CEL/warning messages. Initial inspection from the wheel well isn't showing anything abnormal like a post-cat break at a weld. I put the heat shields on, so really can't see the coils, but I would expect a loose plug would burn through the coil and CEL.

A Porsche tech at the track indicated it could be a crack in an exhaust manifold weld or the manifold gasket. Another guy had a catastrophic failure of a weld this weekend that melted a couple of coils. The tech indicated that exhaust manifold/gasket failures are somewhat common on 981's that are tracked. Anyone else experience this?
 

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Hi Ledbette,

A few years ago, a tech found that I was missing a header bolt during an oil change - I never had the headers worked on or removed - the bolt just came off on its own.

I doubt this is your issue - but worth checking. However, I never heard anything different at the time.

Ed
 

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Replaced the header gaskets this weekend and it didn't fix my problem. I'm still hunting for the source.
 

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FYI - Here's the noise from go pro hero mounted in the wheel well (looking sideways). I'm still fairly convinced this is an exhaust leak and not some other engine issue, but if anyone thinks otherwise, please chime in.


I inspected the exhaust manifold the best I could without fully removing it. No cracks at the pipes coming from the block and no cracks from the cat backward to the muffler. The mufflers look good as well. Replacing the gaskets didn't help and the old ones looked fine. I can't see where the pipes join in front of the cat because of the heat shield surrounding it, so I suspect that's where my leak is.

I've also had an occasional O2 sensor fault P115B - "Exhaust gas implausible, bank 2", which may or may not be not be related. It could be a bad sensor, or could be this leak is causing a bad reading. The fault is very intermittent - I've had it only a couple times in the past couple months, and this is my daily driver.

I couldn't access everything I needed to get the manifold out when I had it up on the QuickJack last weekend, so I will try again in a couple weeks when I have some spare time.
 

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Discussion Starter #5
WIth this leak, my Boxster sounds like an old VW bus.
 
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WIth this leak, my Boxster sounds like an old VW bus.
My 2 cents worth is that it sounds like an exhaust leak to me too. Is it leaking out from around the sensor? If you put a mixture of water and dish soap around the sensor does it blow bubbles?

I’m no exhaust expert, sorry.
 

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So follow-up here... It was indeed an exhaust leak. The leak was coming from under the heat shield where the header pipes join before entering the cat. When the exhaust was cold at start-up, you could feel the puffing of the exhaust coming from the circled area and from the back side of that heat shield seam as well.

I didn't take the heat shield off to examine, but I suspect a broken weld. I drove it probably about 2K miles with the leak, and you can see the resulting sooting from the exhaust.

Interestingly, another guy at the track had an exhaust leak on the same header (driver's side) on the same same day. However, the effects were much worse in that his was on the engine side and the hot exhaust melted two coils and the ignition wiring. His was a Cayman S, also a 2014, and had about the same number of miles (about 67K). I'm not sure exactly where on the header his leak occurred. I'll catch up with him at a track day sometime after the first of the year.

I'm hoping this is not another common issue. It's something to keep an eye on for sure.

266012
 

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Thanks for sharing the resolution. I was going to suggest looking for soot, it’s usually the easiest way to find an exhaust leak. If it were me I’d probably just switch to aftermarket headers at that point, some of them have a lifetime warranty.
 

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Discussion Starter #9
I looked at aftermarket headers, but was able to pick up an OEM on eBay for $245, and got an offer for my old one for $200 by one of those catalytic converter recycling places, so sticking with OEM for now.
 
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