[Son_of_Thunder]

Well, I got my new car a while back, and today I noticed a weird noise coming from it.

Whenever I accelerate I hear a fart-can noise, like something is screwed up with my muffler. The part that's confusing me is that it only does it while I'm accelerating, and not when I rev it in neutral.

Does anyone know what it could be?

[YAYitsAndrew]

Sorry, I had mexican for dinner.

[Falstaff]

Originally Posted by YAYitsAndrew

Sorry, I had mexican for dinner.

Bloody cannibal.

[CDsDontBurn]

could be something in the tranny if it only happens during acceleration

[LuCifer]

Cant be from the tranny if the noise comes from the back.. no?

[pr0digal jenius]

if it doesn't do it in neutral it may be either wheel/axle noise, or tranny noise...but CANT be exhaust noise

[niceguyrichy]

steering rack (?)

they can make a hellish noise if something goes wrong with them that you wouldn't hear just sitting revving it.

[YAYitsAndrew]

lol, tranny

[Customgamer1]

Well if it's a new car just take it in to the dealer and have them look at it! If it's under warranty then you have nothing to worry about!

The bad news for my car was that I needed a new tranny because mine teeth between 2nd and 3rd gear were hitting and making like a clinking/ping sound. But the dealer covered it so I saved $900!

[BWX]

Originally Posted by pr0digal jenius

if it doesn't do it in neutral it may be either wheel/axle noise, or tranny noise...but CANT be exhaust noise

In neutral there isn't a lot of pressure being put on the engine and transmission mounts..

The engine / transmission is connected to the car body through a series of mounts and the header, or exhaust manifold is connected to the engine.. Most of the time there is a flex-pipe of some sort (for front drives) that connect the header and down-pipe to the part of the exhaust that is underneath your car and connected to the muffler/etc.

The engine and transmission mounts are designed to flex so that there is some movement allowed and to isolate vibration and other reasons- anyway, that flexing is motion that is then transmitted to the header and down-pipe of the exhaust system, and that motion is supposed to be pretty much eliminated by the flex-pipe- so the exhaust pipes don't rip themselves apart.. One side is attached to the moving engine, and one side is connected to the stationary car body. Under heavy acceleration maybe the flex-pipe isn't flexing enough and it is making the rear part of the exhaust system move just enough for it to touch another piece of metal under the car.

The exhaust system in cars these days is snaked through the under-body of a car pretty close to other things sometimes.. Especially the heat-shielding. Everything is probably hung on rubber rings connected to pins- all designed to allow movement. Something like that would mostly only happen when the car is moving, but can also happen during revving of the engine in neutral if it moves the engine enough.

I am assuming you have a front wheel drive car with a transverse mounted engine. I had a Honda Prelude that had a problem exactly like you are describing once after I had a new exhaust system put on it, but it surfaced about a month after it was installed for some reason.. I guess those parts take a while to get warn in..

[nerdrock]

We might be slightly more effective in helping you, if you told us what kind of car it is

Regardless, get it back to where you bought it ASAP and find out!

[CDsDontBurn]

Originally Posted by nerdrock

We might be slightly more effective in helping you, if you told us what kind of car it is

Regardless, get it back to where you bought it ASAP and find out!

it's a nissan sentra SE-R .

[nerdrock]

ahh. pardon my ignorance.

New Advice: sell it and get a stick! spice up your thread a little. have a mod move it to the buy/sell forum. Be all: Selling 2002 SE-R : Low mileage ,Automatic, Loved, Fast, Makes awesome sounds (Extra ricy , no extra charge)!

My first car was a Nissan Stanza and it was a pile of Hell, so i might be a bit bitter

My only non-expert diagnosis would be , since it's only making these sounds 'Under Load' , to look at BWX's post, that's about the only thing i can think of. Does it make said noise in Reverse, or just Drive?

[BWX]

Oh yeah I forgot about that thread.. I knew it was a front drive car, I just didn't know how I knew..

[Son_of_Thunder]

Whoa, my car has really been making this sound since June?

Anyways, I figured I'd give an update on the situation. I took it to the dealership and after about 12 hours of inspecting it (all but one of which I got for free) They decided that part of the problem was a loose muffler heat shield...the other problem was a loose wrist pin. I guess that I have between 100 and 100,000 miles before the car throws a pin and dies on me. I can either drive it until death and then replace the engine, or I can replace it now and take the chance that the engine would never have died.

Therefore I'm going to drive it until death, or sell it for around 6K (blue book - cost of new engine)

Oh well, before it goes I'm going to put some money into it. Header, exhaust and CAI to be exact.

[BWX]

Originally Posted by Son_of_Thunder

I took it to the dealership and after about 12 hours of inspecting it (all but one of which I got for free) They decided that part of the problem was a loose [COLOR="red"]muffler heat shield... [/COLOR]

Originally Posted by BWX

Under heavy acceleration maybe the flex-pipe isn't flexing enough and it is making the rear part of the exhaust system move just enough for it to touch another piece of metal under the car.

The exhaust system in cars these days is snaked through the under-body of a car pretty close to other things sometimes.. [COLOR="Red"]Especially the heat-shielding[/COLOR].

LOL I was right!

[wiskerbizkit]

a wrist pin would make a tapping noise not a pop and it would most likely do it in neutral also. Just keep driving the thing. If its a wrist pin theres no telling how long it will last. My truck has had an engine knock since 1986 and its still going strong at 298k miles.

[Son_of_Thunder]

Yeah, I don't think I posted about it when my car started w/ the wrist pin noise. The original post was a loose cat shield, which I got fixed for five bucks. I don't think the wrist pin noise started until early September.

EDIT

here's my car btw:

[BWX]

Funny thing is that same old Prelude I had years ago also had a wrist pin that was knocking a little.. it started on a trip to NC from NY one summer..

I drove the car till it had 150,000 miles and it never self destructed. The noise never really got any worse either. Nissan engines are every bit as bullet proof and indestructible as Honda engines these days.. so I wouldn't worry about it. I also bet you could get a used engine from a junk yard a for a LOT less than 6K... probably they will get cheaper every year, so if you want to keep the car if the engine ever does blow, you could probably get a replacement engine + installation for about 2 grand or maybe even less.

The last engine swap I did in a car I got done for less than 1000 bucks.. 30,000 miles on the Chevy 3.1 OHV V6 engine- I got that for like 400 bucks or so and the labor was the rest of the money.

[Falstaff]

I have to agree...would rather drive a sentra or any other Nissan rather than a Honda Product, just personal choice, I really think the Honda is rather refined mechanically, but troublesome after a certain age. I replaced several front brake rotors that were warped from just driving in southern california..had to go to vented discs eventually and metallic pads.

[Son_of_Thunder]

Used engine plus installation is 3K-ish. VQ35DE (maxima/350z engine) swap is 5K.

[pr0digal jenius]

350z motor......in a sedan......sounds like a weight ratio blunder waiting to happen


nice car though...always liked nissan's styling queues [aside from the new GT-R skyline "thing" )

[Falstaff]

The Nissan products in Japan are a whole lot nicer too!



Nissan Fairlay Z Revised in Japan

Nissan Motor Co.'s iconic 36-year-old flagship sports car the Fairlady Z, known as the 350Z outside of Japan, went on sale in Japan today with new features, including a more powerful engine, as well as enhancements to its exterior and interior.
The Z, whose tagline is "SHIFT_sports," is available in more than 95 countries and has sold about 1.6 million units worldwide since 1969. The current fifth-generation Z (Z33 model) alone has sold a total of about 160,000 units globally since its release in July 2002.
As part of its remodeling, the maximum horsepower of the Fairlady Z's VQ35DE engine - the same engine that powers the 350Z anniversary model released in Japan in January - was boosted to 216 kilowatts (294 PS)/6400 revolutions per minute, up from 206 kW (280 PS)/6200 rpm. Power was boosted by increasing induction efficiency with larger-diameter air ducts and retuning the valve timing, among other improvements.
The renowned handling qualities that have always distinguished the Z have also been further improved by adopting dual-flow-path shock absorbers and vehicle-speed-sensitive power steering.
While continuing the basic design cues popular among customers, the Z's exterior styling has been enhanced thanks to a redesigned front bumper and headlamps, as well as the addition of high-brightness light-emitting diode (LED) rear combination lamps. The remodeled Z has also been given newly styled 18-inch aluminum wheel, available on all grades.
The interior features greater use of authentic aluminum accents, soft-feel materials, additional storage spaces, an optimized control switch layout and other refinements helping to enhance the Z's quality and convenience.
The remodeled Z is available in a total of eight colors, including three new choices: Premium Mystique Maroon (RP), Brilliant Silver (M) and Diamond Black (P).
Nissan also announced that Autech Japan, Inc., a wholly-owned Nissan affiliate, has equipped the Fairlady Z Driving Helper lifecare vehicle (LV)* with the Autech Drive Control Package Type e, a set of electronically controlled driving-assistance features designed for drivers with leg disabilities.

*Nissan group companies use the term lifecare vehicle (LV) to refer to vehicles that are specifically designed to assist persons with special mobility needs in their everyday lives.

Fairlady Z major specification and equipment refinements

< Engine and performance >

Engine with maximum power increased from 206 kW (280 PS)/6200 rpm to 216 kW (294 PS)/6400 rpm (available on 6-speed manual transmission models)
Adoption of dual-flow-path shock absorbers and vehicle-speed-sensitive power steering
Standard brake size increased from 16 to 17 inches

< Exterior >
Redesigned front bumper and headlamps
Adoption of high-brightness LED rear combination lamps, newly styled 18-inch aluminum wheels and Titanium Clear outside mirrors
Selection of eight body colors, including the all-new choices of Premium Mystique Maroon** (RP), Brilliant Silver (M) and Diamond Black (P)
RP: Multi-reflective Paint M: Metallic P: Pearl
**Premium Mystique Maroon is a current revival of the Gran Prix Maroon color adopted for the long-nosed 240ZG model that was added to the first-generation Fairlady Z (S30) lineup in 1971. Embodying the themes of "newness" and "Z-ness," this new premium color is distinguished by subtle changes in hue depending on the viewing angle and ambient light condition.

< Interior >
Increased use of authentic aluminum accents, including for the knob of the cupholder cover, rings of the trio of ancillary gauges, shifter finisher, air-conditioner control dials, navigation joystick ring and other locations
Adoption of soft-feel pads for the door trim
Use of soft-feel paint on the door handle panels, hoods of the trio of main instruments and trio of ancillary gauges, center console and audio/navigation system control panel
Additional storage spaces, including a card holder, cargo net at the bottom of the front passenger's seat, illuminated beverage holders in both doors and larger door pocket openings, among others
Adoption of new seat fabric

Dealers selling the Fairlady Z:

All Nissan dealers

Price range:

3,328,500 yen to 4,483,500 yen

[Son_of_Thunder]

Originally Posted by pr0digal jenius

350z motor......in a sedan......sounds like a weight ratio blunder waiting to happen


nice car though...always liked nissan's styling queues [aside from the new GT-R skyline "thing" )

The VQ35DE is in a lot of cars, including the maxima and altima. It's becoming fairly trendy to throw them into Sentras, seeing as with them they can hit 240hp without further mods. 240hp in a car the size of my sentra would be insane

[Falstaff]

Originally Posted by Son_of_Thunder

The VQ35DE is in a lot of cars, including the maxima and altima. It's becoming fairly trendy to throw them into Sentras, seeing as with them they can hit 240hp without further mods. 240hp in a car the size of my sentra would be insane

If it were an ALTIMA I could see that as well...but then I am biased

[pr0digal jenius]

you've clearly never driven a Sentra SE-R


omg those things have some cajones.

[BWX]

Yeah they go pretty good.. they do best in the twisty stuff, straight line is pretty good but not super fast unless you do some mods - like a turbo etc..

This one still goes really good.. 0-60 in about 7 seconds..






Not so much in this weather though...







Even worse in this weather- of course with the limited slip differential it does better than most regular small front drive cars..

[pr0digal jenius]

in FWD cars, in the snow/ice...they do much better if you stick a few 50 pound bags of sand in yer trunk

[Son_of_Thunder]

Isn't that a 200SX SE-R though, and not a Sentra SE-R? (same diff, but still)

[BWX]

Yeah it is.. before that there was a sentra SE-r.. (body style before that- the little boxy one)- then there was also the identical car without the sport package at the exact same time as the the body style of the pics above called a Sentra..

Then the next body style was called a Sentra SE-r instead of a 200sx again. Same concept really, just different names.