oxygen

I am hoping, praying that someone has experienced this besides me. This is one of the main reasons why I want to get rid of my Maxima. It's driving me insane. Every time I accelerate around 2k RPMs or if I take my foot off the gas and tap it down quickly I hear a very loud rattling/rubbing/humming noise. It does not happen at ALL times just when I press down on the gas rapidly or accelerate hard. It does occur if I am coasting maintaining speed at 2k rpms also. I thought it was possibly one of the plastic motor shields, so I took that off and it's still doing it. The shocks are in good shape, I inspected those. Tie rods are good, and wheel bearing appears to be good. I am hoping someone knows what this is. The only thing left I can think of would be a motor mount or a trans mount since it happens under rapid acceleration... ANYONE experience anything like this? I've searched here, looked through numerous threads, etc, searched google, can't find anything. Please help!

IHAVEA2KMAXIMA

iTrader: (7)

Is it coming from the engine bay or where...? It might be the plastic shield that protects the flex section on the y-pipe.

oxygen

Its hard to tell cause I dont have anyone else here to help me test it. It sounds like it's coming from the passenger side of the engine bay. It's def from the engine bay though or that general vacinity. I took off the shield protecting the oil filter/belt but that wasnt it.

Rochester

iTrader: (3)

Which is it: rattling, rubbing or humming? How long have you had it, and is the problem easily repeatable?So many noises; this could be a Sesame Street skit! One of these sounds is not like the other...

Whatever it is, don't dump your car. Chill out, get some focus, take it to the shop and get it fixed. But selling your car because it makes a noise you can't figure out...? That's nuts.

oxygen

I know, I agree, its hard to diagnose via internet without hearing the sound. I may try and shoot a video - Only reason I'm resorting to here rather than a mechanic is because funds are limited lately and I'm trying to see if anyone else experienced it and it might be a quick fix. I'd consider it more of a humming than anything else

Rochester

iTrader: (3)

From the engine, you say? It could also be pinging, which is fairly common in the 5.5 gen between idle and 2000 RPM.

Or you might be burning oil, to where you're routinely low, resulting in that pinging noise.

Network your area to find a trusted shop, and bite the bullet. Very doubtful you'll get your answers on the web to a Mystery Noise. Possible, sure, but unlikely.

Good luck, man.

gotendbz1

iTrader: (1)

just search the word pinging and you will find your answer.

Rochester

iTrader: (3)

Do you have to be moving to hear the noise, or can you repeat it in park?

oxygen

Has to be moving to hear the noise, don't hear it in park! I forgot to mention that! It's not pinging either. We own another Max which pings so I know what pinging sounds like. Just did an oil change too so its not low on oil.

Rochester

iTrader: (3)

Engine Pinging sounds like a coffee can half full with nuts and bolts, muffled in a bath towel, and shaken 4 or 5 times.

Hey, that's a pretty good analogy!

Rochester

iTrader: (3)

Try putting the car in drive, but keep your foot hard on the brake. Then gas it so the engine lifts (assuming you have OEM mounts). If you hear the noise, it could be your mount bushings or front suspension.

It would help if you had a second pair of ears to scope it out.

oxygen

I tried your trick Rochester, and did the brake stand. The rattling does not occur when in park and revved to any RPM or when doing the brake stand. RPMs hit 2000 no problem and still no rattle. I dont know if thats a good thing or not. haha.

maxs4life

iTrader: (1)

front catylic converter is my problem... rattles at a steady 2000rpms. It comes and goes as it pleases. sometimes its louder then others...

oxygen

I'm thinking thats what this is too. I had my mother ride with me and she said she thinks its the exhaust. It would make sense why its doing it only on acceleration. It doesn't really rattle at all though when in parked revved even to 6-7k RPMS. does yours rattle when in park Maxs4life?

Rochester

iTrader: (3)

Then you can *probably* rule out the mounts, struts and springs. Which is good, because that stuff would kill your budget... since you said you don't have one.

And since you're calling it a "rattle" now, that brings you back to the exhaust. I remember way back with the OEM exhaust (in the long long ago), the pre-cat was all rusted. It kind of sounded like a soupcan with dry rice in it.

Get the car on a lift, or ramps, and check out your exhaust. Look at the dust shields behind your rotors, too.

I'm kind of out of ideas. Did I mention that I'm not a mechanic? Again, good luck.

oxygen

the pre-cat is pretty rusted up, I've played with the dust shields behind the rotors too and thats not it... Whats the solution though if it is the pre-cat converter? Just replacing the pipe?

Mr. Brett

iTrader: (7)

I'm pretty sure we've been over this rattling, and I'm pretty sure it is some kind of pre-detonation. Here's my two cents on why:

My Max was rattling like crazy between 2k and 2800 RPMs. Until I did three things:

1.) Seafoam in the manifold to clean out the carbon deposits.
2.) Next, I took throttle body cleaner and cleaned all the junk/tarnish out of the TB.
3.) Finally, I switched from mid-grade to premium.

I've since had to switch back to mid-grade due to the price of gas , but my car hasn't made any rattle since June. It's just now starting to do it a little bit again, but only under "spirited" acceleration. Which leads me to believe that the gas I'm using isn't pure enough. Or that my TB is getting gunked up again.

The reason that it won't rattle when parked is because the car's engine isn't under load. Does the rattle get louder than normal if you try to accelerate uphill?

By the way, if it is the precats, you could always gut them, or run headers. OEM precats are going to run you a pretty penny.

Rochester

iTrader: (3)

If it's your original, 8 year old exhaust, I think you know the answer.

Get it up on a lift, shake the exhaust, and you'll know for sure.

Gemner

iTrader: (4)

my heat shield on the rear cat rattled at somewhere near 2000rpm and light load until the day I traded it for a set of headers. Maybe thats what you need to do

blueMax711

I am with you oxygen this is the main reason i started to look on the forum, although i got alot out of it already, god bless the forums. the car is my gf's daily driver and when it hits 2k rpm it rattles i have checked all heat shields and no luck one mechanic told me to check the EGR valve. Its referred to as a Pinging but its a rattle. i have tried to put the car up on jack stands with the car in drive and rev it up to 2000 rpm and no noise it just happens when there is resistance. There are ALOT of people with the same prob put it into google and see how many questions and answers come up theres about a dozen(some really stupid solutions too). i hope this helps or makes you feel like your not alone going insane...I havent heard about the cats though im gunna try it tomorrow.

maxs4life

iTrader: (1)

never in park. only when im driving forward...
I went crazy with this... I use high octane gas and i got this problem...

now i have a question
what can i do to remove this problem without buying a new Cat Converter.
what other options do i have?

maxs4life

iTrader: (1)

its def not a suspension problem.
this sound is annoying...
after the holidays i will spend the big bucks if i have to on the problems but right now im just gonna keep the volume up.. lol

oxygen

I'm glad that others know what I'm talking about and dont just think I'm crazy haha. I think it's got to be that first cat thats doing it. I wish there was a quick solution to this but it seems like its another $1,000+ repair. I'll add that to the list

Rochester

iTrader: (3)

$1000? No, man. Don't do that.You can dither with the numbers +/-, but the point remains. If you have to do this, it's an upgrade opportunity, not an unwanted expense. Embrace it, don't complain about it, you'll be happier for it in the end.

TMoney_87

I same sort of rattle to, its only around 2000rpms and only when I'm in drive. I know what knocking and pinging sounds like ands diffenently not that.

At first I thought it was the heat shield on the cat. So I got under the car and it was loose, so I tightened it with a trident clamp(only thing I had).
Then the other day after I was done changing my oil I just happen glance at my flex pipe and the medal mesh is pulled back at the front towards the engine, about a 3/4 inch gap. I'm not much of a pro with these exhausts compared to my old car, but it doesn't look like its supposed to be like that.
Car still runs quiet though.

Oh yeah tightening the heat shield didn't fix the rattle.

cmd26

iTrader: (6)

Ive had that for a few years now its annoyin but Ive learned to live with it. hope u find a solution GL>

fuctkeen

could be your MAF. try cleaning it.

DMAXXX

SORRY TO BUTT IN BUT IT COULD ALSO BE YOUR RUNNING TO LEAN OR AS I SAY ALWAYS GO 91OCT. OR 94

CLK04MAX

I was having the same problem (rattling during acceleration) and it was the heat shield.... the clamps were rusted out. I knew my car came from up north and immediately realized why they were rusted. They salt the roads a lot in the winter and it can do a lot of damage under your ride. My advice for those that live in these area...remember to rinse the undercarriage, it will save you in the long run! Hope this helps..... it took me a few months to realize what was making that sound!!

CLK04MAX

let me clarify that....the exhaust shield.

cmd26

iTrader: (6)

I was thinking the same thing about cat converter or maybe even the transmission, cuz I think only ATs have this problem.

Kreapin

I am sorry for chiming in so late to this thread but I had the same problem. I switched my oil from 5w30 to 5w50 and badda bing, noise is gone. From what I hear though, the oil runners are narrow on this motor and they get clogged so a good engine flush should clear this up. I havent done it yet but I plan on gettin it done next oil change.

Deckdout2

iTrader: (151)

I've had the same issue, and when it rains it's more pronounced. I just changed my break pads and I noticed that my inner axle boot was completely torn all to hell. I know what my culprit is, and it might be the same for you. Check your axles, I just ordered 1 today from raxles.

03blackSE

Wow, that's odd. It's the opposite for me. My rattling sound completely disappears when it rains.

Putting in 94 octane cleared up the sound quite a bit. But the high ethanol content (Sunoco) was killing my mpg so I switched back to Shell 91, and my rattling sound returned.

A few people have suggested a new MAF. I'm hesitant on that since they aren't cheap and mine seems to be working fine (good power past 4000 rpm).

Next thing on my list to try is some seafoam in the gas tank to help clean out my fuel system....

sublime258

iTrader: (9)

I have been having the same sound for about 2 years now. I actually created a thread about it last year. My sound is a rattling noise which sounds like it's coming from the back of the engine at around 2000 rpms. It's only when I give the car gas and never when I'm coasting. I am able to duplicate the sound if I'm holding the brakes and giving the car gas in drive. I think it's my precats, but I still haven't taken it to the garage yet. I am thinking about taking it to the garage to get my Cattman y-pipe installed (nuts and bolts are rusted together) and have them take out my precats while they're at it to see if anything looks wrong with them. If they are deteriorated at all, I will probably just punch out the guts in them and hope that works. I know there are a LOT of people that have had this issue or a similar issue, and I don't think there has really been a solid solution.

ZGadson

See Highlighted above. I posted this here, and then saw that uphill thing. What does this mean?

My car has the same issue - rattle between 1500 and 2000, and gets even more noticable when driving up hill at those rpms. I had my car at a shop the other day for some engine work and asked about the rattle. The tech heard it too when he test drove it, and said it was the TPS valve. I had spark plugs/wires, an oil seal, and some other random thing replaced, but the tech said a new TPS valve was part of whatever they replaced last.

The problem apparently isnt the TPS valve because the car has a new one and it still rattles. And yes, the sound is coming from the engine bay.

My car has one hell of an exhaust leak and major power/acceleration issues when its at operating temp, which, after MUCH deliberation, research, forum reading, shop visits, Ive decided has something to do with the main or pre-cats. But like Sumblime says, no one has found a definitave answer for this issue.

Also, I've always put in regular low-grade gas in my cars, but occasionally I fill it up with premium just to clean out the system. It's got 97k miles on it and different grades of gas have never had much of effect on the noises it makes or the power it has (or lack thereof lately).

grayfox

I had a similar issue it was most noticeable at around 2200rpm's, It was the head shield on the side of the catalytic converted close to the engine, The shield its self was fine but the mount for it had rusted and started to break. To remove it I just jacked the car up and gave the heat shield a good hard kick, The mount broke apart and it came right off.

If yours isn't as rusted as mine was you can remove it with a socket. (Im not sure what size).

ZGadson

I don't know about the socket, but that kicking part sounds like fun. I'm getting so tired of this car and its problems. Its such a lemon.

But if someone could look up at my previous post and give some nice opinions or advise I'd love them forever.

jasonmax

iTrader: (2)

fix the exhaust and use premium gas, dont be such cheap and blame the car if you dont treat it well

premium gas wont clean anything, if you keep using regular your engine will be damaged due to pinging, learn how octane works, gee.

no wonder the shop would tell you to replace the Throttle Position Sensor "valve".

Rochester

iTrader: (3)

Come again?

Octane additive retards ignition for cars with higher compression requirements. It doesn't have magical cleaning properties.

The VQ is recommended for 91 octane. If you're pinging, try running 93 and see if that helps. If not, try applying an upper engine cleaning process like Seafoam.