I have been searching and reading tirelessly on this, and I don't know where to actually start work.

Car information: 2008 350Z Base MT with 56,XXX miles on it. Only engine mod is JWT Pop Chargers purchased with the car. It does have GReddy EvoII cat back, but I doubt it's the culprit. I daily drove the car for about 45k miles and now it's my weekend warrior seeing minimal spirited driving spurts and no track time for 5+ months ago which was only 2x in her life. Canyon runs were bi weekly but I rarely red lined during those.

I bought it used with just under 8k on the clock so I don't know what oil was used in it for the 1st couple changes. I used Royal Purple Full synthetic 5W-30 for the next 35k miles then switched to Mobil1 full synthetic because "RP is bad for the VQs". I don't know if this comes into play, but I hope not. I always changed the oil closer to 4,500 miles than the 5k too and check it every few weeks, never seemed low or that it was burning oil. I haven't noticed any smoke from the exhaust either.

Searches have turned up the "Fuel Damper" or "fuel surge damper" and I'm hoping that's it, since it seems I could take care of that myself with only parts as my cost. It seemed to me like most of these cases were for the DE though.... am I wrong? The noise doesn't seem to raise and lower with revs, but this is the only video I have for now, more could be made if needed.

I have also turned up valve issues and piston slap. Neither of which do I feel confident in diagnosing myself, or attempting to correct myself either.

Here is the video, hopefully this helps and we can narrow down the issue.

Note: I have the clutch pushed in, so it's not the clutch/flywheel chatter we all know and love.

UPDATE: 5/2/14 I took my car to the dealer and they replaced the passenger side cat for free under the 8 year 80k mile federal regulation/law/whatever. I have not noticed the noise since.

 

Oh, yea, thank you for your time and any help you can provide.

 

Kinda hard to tell from the vid. But sounds like a exhaust leak

 

Any suggestions on tracking it down or making it clear this is the issue?

 

I've heard of using seafoam to check for exhaust leaks or leaks of any kind. There are videos on youtube and more info on how to use it on the net. I looked into it when I thought my jeep had an exhaust leak because it was throwing a code but it wound up being an o2 sensor. If you don't have experience with seafoam look up some videos on it and how to's. It seemed pretty easy to do.

 

Thanks! Im going outta town for work today, then going to Vegas when I get back so it may he a couple weekends till I get to anything. It's crappy timing too since winter is almost here and I wanted to get some more cruises in before the dreaded winter storage. Will keep this in mind tho!

 

Yeah I feel you I'm dreading winter myself.. It's going to suck not being able to drive my baby for a few months . But yeah I'd say go for it. It literally only takes like 10 minutes to do the leak test.

 

If I did this im looking for the "smoke" to come out of the engine bay-right?

 

You would if you were looking for a vaccum leak. your looking for an exhaust leak. have someone lightly hold a rag over your tail pipes. this was while your looking at your exhaust if it does have a leak it will escape through the crack or hole that you are looking for. if you dont cover the tail pipe the smoke will just go out of it and make finding the hole harder. Theres some vids that show what i'm talking about on youtube and some write ups about this online. I'll try to find some links for you

 

Heres a vid I found that doesn't use seafoam which you may be able to try also. Note that I do not own this video or have any part of it's content and shall not be held responsible for anything.

 

Heres one using seafoam. Sorry got the rag mixed up lol. Watched a lot of videos when searching this for my jeep a couple month ago. Note that I do not own this video or have any part of it's content and shall not be held responsible for anything. . I've only heard/ read reat reviews on this seafoam stuff though. You can use it for your oil, gas freakin everything and on everything. I've never used it. Mainly because I'm not good at measuring liquids when mixing them haha.

 

Ima need bath towels to plug up my EvoII canisters! Haha thanks for the vids though. The one seafoam vid I watched on my own had a guy at 7k rpm for about 35 seconds. Idk how my neighbors would like that. Hahahaha

 

lmao yeah. The hell with the neighbors. As long as it's during the day/ afternoon they can't do anything about it.

 

UPDATE I put Seafoam in the oil, and gas and drove for 20-30 minutes-still no change

I got under the car and tried to feel for exhaust leaks. I wedged a jackstand on the clutch so it's NOT the flywheel/clutch/trans noise.

I noticed the noise was mostly near the passenger side cat. I put my ear NEAR the cat and it sounded like that was making the noise, but I don't know why the cat would make the noise. The exhaust was hot so I didn't feel around too much. I will most likely be doing this alone, anyone have ideas on how to track down the noise further?

here is the video

 

Bump for new video!

 

Update! Took it to the dealer and asked about warranty. Im still covered until march of 2014. I have an appointment next week to check the engine. If that fails I should be covered under the 80k 8 year cat coverage. I hope it's one of those two things since I have to get her in the garage for winter

Open to suggestions until I take her in!

 

UPDATE! Dealer said it was the passenger cat beginning to fail. They have to order it and install but to know it's under 8year/80k mile warranty is great. Will update after cat install

 

4,500 mile oil changes? Blasphemy. Mobil 1 synthetic? Blasphemy.

 

Please explain.

 

I thought the standard for oil changes was 3,000 miles/3 months. Also Mobil 1 synthetic sucks. I used it for the entire time I had my car from 44k to 115k, never again.