I recently purchased a used 2004 G35 6MT coupe (129kmiles). So i have a few concerns the car for the most part is amazing happy to finally own one considering ive wanted this car since middle school! So first on the list of concerns is

1.my trans tunnel gets warms i can feel hot air while driving coming from that area
2.the guy i bought it from put a really cheap clutch from ebay and while accelerating i hear a rattling at low rpm (i believe its clutch chatter mixed along with noise from the throwout barring

other then that the car is really clean just mainly cosmetic things thanks for any help im happy to be apart of the g community now!

Ps im a starting mechanic im comming from building/lifting jeeps so this is a new platform for me

 

Does it feel like hot air "blowing" or just got air "radiating" from that area.

I suspect that during the clutch job they removed the factory heat shields above the cats as well as possible removing the heat shields from the cats themselves. Get the vehicle up on jackstands and inspect.

 

He also installed a new y pipe and cats and from what i saw there was no heat shields around them or near them and as far as how it feals when im driving it feels like its kinda blowing but mostly radiating its kind of hard to explain haha

 

Yeah it sounds like missing heat shields, it will have pretty significant convection so it will feel like it's blowing sometimes. You can add aftermarket heat shields which I do recommend for anything with catalytic converters. The heat that radiates off them is INCREDIBLY hot. The only time an exhaust will be hotter is the headers/turbo on a high boost engine that's been running hard and you usually wrap stuff like that. Regular dimpled sheet metal works fine, look up some Google examples.

 

Would somthing like this work if i wrap both cats?

 

Unfortunately you CANNOT wrap the cats like you would headers. They have to be able to dissipate heat. Shields are the only option.

 

Go down to a local reputable muffler shop and see what options they have for welding on some heat shielding. Usually they have corrosion resistant metal that they can tack weld onto the edges.

 

Welcome, I've got a 6MT G coupe as well with OEM cats, the heat shields have long rusted off and I don't get any of that radiant heat from the trans tunnel like you mention.

Have you checked to see under the leather shifter boot that the rubber shielding boot sealing the hole to the undercarriage is in place properly? If that was damaged during the clutch install and left out there'd be a straight path for hot air to blow right into the cabin through the shifter assembly..

As far as the clutch noise, if it makes chattering while the clutch is out but goes away when you clutch in, it's normal rattle from an aftermarket single mass flywheel, you'll get used to it. Depending on the weight of the fly it'll also rattle under acceleration at low RPMs, its actually the gears in the tranny rattling since the OEM dual mass flywheel isn't there to absorb the engine's vibrations.

 

Ill definitely check out the rubber shift boot today at some point as far as clutch and flywheel what would you guys recomend to use to have as little chatter and nice performance i do plan on ditching the pos he put into it as soon as i can

 

Honestly I'd leave the ebay clutch in it and see how it holds up, and abuse the hell out of it knowing it's cheap, with parts and tools to replace it on standby.

I've always used Exedy clutches because of their OEM status on Toyotas and reputation for good QC relative to their reasonable price. Z1 motorsports sells rebranded Exedy kits specifically for Gs with lots of different performance options if you want to do a lot of clutch drops, launches, or plan to go nitrous/FI in the future.

I've got a Z1 Mild Performance/OEM spec pressure plate with a full face organic sprung disk which is basically an Exedy OEM replacement. No complaints although I'm not asking much of it compared to someone who might drag race their car from a dig or drift. It works great for WOT redline highway pulls and the mild launches I do in autocross, and I can drive it in Boston highway traffic without wanting to die.

If you want more performance for clutch kicks, forced induction, or hard launches Z1 has "race" parts tested to work with the Exedy stuff, check it out.... or pick up one of the many high end clutch kits out there for $$$.

As far as chatter, any single mass flywheel will chatter, but lighter ones chatter more. The one currently installed in your car from the ebay kit is likely an 18 lb steel flywheel, the same one I have in my car. IMO it's a good compromise of performance, noise, and OEM daily drivability. If you can't stand the chatter either get a super heavy steel flywheel (Z1 sells one) or just get another OEM dual mass.

If you end up reusing the ebay flywheel (a steel flywheel's a steel flywheel...) with a quality brand pressure plate and disc, it can't hurt to have the whole thing machine balanced at a shop for ~$100 to be sure your rotating assembly won't be off balance with the mismatched parts.

Oh, and pollyurethane engine/trans mounts magnify the chatter in the cabin probably 2-3x so be aware if you ever install those or have them installed already.

/study break over

 

With a loud enough exhaust you barely even hear it.

 

I have a quiet exhaust