Rattle me this

[jimbyjimb]

I have a rattle under my car, sounds slightly right justified, hard to tell if it is front or back and can only be heard with the windows down. It is not a clunk, it is definitely a rattle. I've been under the car several times to try and find it and here I stand: All steering components tight, boots on rack broken but won't rattle so nothing there, front wheels/brakes/rotors tight and do not shake, rattle or loosen with pulling/shaking/kicking/turning/biting...er, Calipers tight, all front suspension hard parts tight with seemingly good bushings, flex hoses good and tight, strut boots are broken and struts are possibly suspected though I would expect a different noise from them and they seem to be in good working order without excessive roll or bounce and I cannot duplicate the rattle manually with them, the cats don't seem to be rattling and everything around the transmission/driveline upon inspection/beating seems tight and in good order. I haven't done as thorough a job in the back yet, but the wheels/tires/brakes seemed fine when inpected/beat also. Is there anything that is a common cause of rattle under the first Q's? I've searched through the threads and came up with cat mounts, but those seem to be just fine, are tight and in good condition. Any more suggestions no matter how small would be greatly appreciated. The rattle drives me nuts since the car is in perfect working order EXCEPT for this rediculous rattle. The rattle only occurs on rough surfaces/bumps and not on smooth freeway surfaces. Thanks alot!

[Q45tech]

You are not spending the 8 hours per month under your Q.After seeing a few hundred/thousand rambling wreck Q you immediately know where to look.Have you used the hose clamps on cat and pipes heat shields and replaced as they rust?

Admitting to broken rack boots is like admitting to child abuse..........there is a mechanical angel at the gates who stops these abusers from entering.

If you fix boots IMMEDIATELY and maintain clean power steering fluid the racks will last forever.

[jimbyjimb]

I bought the car this way and have had it three months, give it some time. I'm sure in the last three months I've logged well over 8hrs per month under my Q that I have been taking as best care of as my means and time allow. There is no rust, and the heat shields have been eliminated as a cause and are in like new condition along with the cats which I typed previous have been inspected already and also eliminated. I'm not asking for a chastizing or opinions on what I'm not doing right with MY car I've had for THREE months or someone to explain to me the things I have been practicing in the field for over 4 years. What I am asking is if any older members have any constructive input on past experiences with rattles and if there are any common causes linked to this car specifically that one may not know to look for unless one had experienced this problem with this car at some point. I am not an ignorant child begging and pleading for the god of automobiles to share basic knowledge with me. While I appreciate constructive input deeply, which you often give, this response was extremely disappointing and a complete waste of your time and my time to type or read. I have not seen a few hundred Q's and this is why I am asking for information a senior member may have through the sheer experience with this car's specifics that I do not have since most conventional causes of this noise can be ruled out. You critisizing me about my rack boots makes as much sense to this thread as me critisizing your approach to helping people. You don't tell someone you have a ton of experience and not back it up by offering no useful information. Sure, you don't have to come on hear and help a brotha out, but there's no point to trying if nothing useful is stated. So anyone who has anything to say about replacing items that are unrelated to this specific problem, take your keyboard somewhere else please. Rack boots don't rattle.

[Q45tech]

So you have 18 years of experience working on your personal Q and driving it 319,000 + miles while spending in excess of $40,000 for parts and labor, and dealing with hundreds of other Q on a hands on basis.

If so I apologize. Otherwise Luckily I can conduct my posts in any method I chose as long as I don't violate any laws or call any member a vile name.

Why you don't see Moderator attached to my name I cannot be politically correct and surely don't try to spare anyone sensitive feelings.

You are perfectly allowed to skip and not read any of my posts.

[jimbyjimb]

No, I don't which is exactly why I asked this question. Now you're just prodding looking for a fight. I was actually hoping that YOU would respond since you seem to have the most experience and 99/100 times have information that is valuable and applicable to the situation at hand, but I'm looking for rattles and your talking to me like an ignorant bystander who buys a 45,000 dollar car and knows nothing about nothing trying to sell me rack boots. I know I need to fix them, you don't need to talk to already experienced mechanics like children who know nothing since you're just as fallible and make as many mistakes as anyone else alive and it is through those mistakes you have learned what you know of this vehicle. Instead of preaching your knowledge reserves open them up is my point. I can sit here and say all I want about my experience but it means nothing until something applicable and useful has sprouted, hurling accusations and assumptions is not what helps and is just plain stupid. I don't make 400,000 a year and am not some rookie who doesn't know a box end from an open end. I'm just a kid who fixes it himself and could benefit in this situation from someone like yourself who didn't feel like making pointless statements and threw something up on the board that he may or may not know of as a common cause of under-car rattling issues. In this specific case you are denying the very fact that brought you here, to help. I like reading your posts because in addition to USUALLY being very informative and factual they have a snide wit to them I find rather enjoyable, but in this instance your just throwing a red cape at a bull by going around the subject and telling me everything that isn't applicable to this situation. I just want to fix my rattle man! So is it that you can't help me or you won't?

[oldmako]

Noises suck.

I'm sure you checked the heat shields on the exhaust? Mine made all kinds of noise for a while. The last noise they made was a loud clang when they hit the inside of the dumpster.

Shame on me. I altered the original equipment on my 9 year old 4500 dollar Q. I also neglected to spend 8 hours under it last month. And to top it off, I only opened the hood once in June. Sorry to degrade the brotherhood in such a despicable manner.

Good luck with the noise reduction.

[maxnix]

I just want to fix my rattle man! So is it that you can't help me or you won't?

He can't as he is in Atlanta. All we can really on is your reports. Any maintenance history on the front suspension? Rear suspension? 3rd motor mount? How's the under engine shield?

As Q45tech reminded us, neglecting a $10 boot can lead to the dimise of a $1200 steering rack in no time.

Better to teach a man how to fish then to only give him one.

We need some better defined bait.
Modified by maxnix at 10:01 PM 7/4/2008

[jimbyjimb]

I'm sorry I bothered this board with a question about common causes of under-Q rattling. Please disregard and may a moderator delete at the earliest convienence.

[maxnix]

I'm sorry I bothered this board with a question about common causes of under-Q rattling.

I guess the point is, there are no "common causes of under Q-rattlling" that come to my mind beyond catalytic convertor heat shields, which sound tinny and are thus are readily identifiable.

Without well detailed decalarative descriptions with a detailed maintenance hsitory, we are at a loss as we cannot witness the uncommon phenomenon.

[Q45tech]

Besides exhaust and heat shield ratting, the only thing I've run across is lowering springs and worn suspension rubber bushing isolators and of course brake dust shield. Plus aftermarket wheels.

Is the rear subframe silicone leaking allowing shifting?

I have a 5 microphone system that lets you mount them and dive and select inputs to narrow down: center, fore. aft, left and right.

Have 2 trained ear friends sit in rear seat and compare notes.

[jimbyjimb]

The brake dust shield could be it. I haven't yet checked the rears. All body bushings are fine, no leakage. Checked those shortly after purchase. The car is 100% factory except the suitcase removal, and the rattle was here before the suitcase mod. All of the front suspension bushings, upon appearance, seem fine but some more detailed examination may be required. I'm fairly positive the exhaust is not the cause since all is in excellent condition and I cannot manually duplicate the rattle no matter how hard I beat the mufflers/cats/pipes. Have cheacked all shields for looseness but to no avail. Eventually I'll find it or something will break/fall off.

I guess the point is, there are no "common causes of under Q-rattlling" that come to my mind beyond catalytic convertor heat shields, which sound tinny and are thus are readily identifiable.

Without well detailed decalarative descriptions with a detailed maintenance hsitory, we are at a loss as we cannot witness the uncommon phenomenon.

My original post on this thread is my service history. Bought used in April. Bone stock, self-inspected. It sounds almost what a loose shackle sounds like on a leaf spring, leading me to believe suspension/differential. The CV shafts are tight and I cannot duplicate the noise with them either. I'm going to do a more detailed inspection of the brake shields per Q45T's reccomendation and see where that leads me. I have reason to suspect rear suspension since the rattle does not seem to occur when the front end hits a bump but rather the rear. It's very possible this could be a non-suspension issue. Because all of the struts seem in fine working condition and I have never heard a rattle like this from a strut I can't see as it's them, but it could be. I will be doing a much more detailed inspection on Monday/Tuesday as they are my days off and the Q needs some more love. Please excuse my outburst but it's enough to have a project car let alone with everyone screaming to do what I already know needs to be done. All things with time and patience. I appreciate the calculated input greatly.

[Q45tech]

Have you checked under rear seat, around fuel tank , the jack driverside compartment, the spare tire well, the passengerside well where antenna retracts.

Lots os space for nuts and bolts to fall and sit.

I found a Japanese lunch bag with a food list to buy in Japanese, beside my fuel tank bottom in 1994 4 years after I purchased.

Sent it to Nissan Japan Chairman with a note.

We sometimes find unusal items in weird places. I once found an ounce of powder. You never know what previous owners lose.

[jimbyjimb]

Off topic but when I was in trade school one of my instructors was remembering the days of the GM strike and told us he found a coke bottle in a fender of a Chevy when digging for a knocking noise in the back. It had a note in it that read "You finally found me you dirty little ba$t4rd". Disgruntled GM employees.

I've checked all those areas but the gas tank, haven't made it back there too extensively yet. Will report early next week.

[carfrk666]

just turn the music up so u cant hear it

did you check your jack and jack accesories?

[jimbyjimb]

Yeah, the rattle is definitly under the car, its not interior or trunk. I'm going to quadruple check my exhaust shields tomorrow as well as gas tank and rear end of car.

[maxnix]

Don't discount old rock-hard exhaust hangers.

[paranoidjack]

I apologize.

Did I really see that? hehe...

as far as the rattle, I'd check stablilizer links (often take a shot before they rattle, hard to copy on the ground). That was my gremlin, often made noise on a bumpy road but I could NOT recreate with my hands....however it was pretty apparenty this was coming from the top of the wheel wells.

[jimbyjimb]

I checked under car again, absolutely cannot recreate the noise through the exhaust system and all suspension pieces/heat shields are tight. I've been kicking, shaking and have even thought of just beating everything to a pulp witha sledge, but haven't, and still have found nothing. The only things I can get to make any noise at all are the shields above the cats, but it is an entirely different sound and so light I wouldn't be able to hear it anyway. I might pull em just to see.

jack- I have suspected the sway bar since it sounds like a noise a sway bar would make and, like yours, is also un-duplicable and only sounds on bumpy roads. Next time I'm under the car I will re-inspect the stabilizers more closely, thanks for the tip. For now it looks like I ca only play with things to try and find it or wait for it to go away on its own, I.E. whatever it is falls off the car or breaks...

[maxnix]

Steering rack bushings?

[[email protected]]

I must say that I am very happy that this conversation ended on a positive note and that jimbyjimb did not leave. Q45tech has valuable info and he has an interesting way of telling us that we should have done our homework. I have been a victim also and never took it personally, especially since I had read quite a few of his posts.

Having said that, I have an 02Q with a similar problem and it has gotten progressively worse. I hear it when I put the car in gear and it is relatively quiet otherwise. My buddy here at T3 in Atlanta found out it was the Heat Shield and I will be fixing it when I have my next oil change service.

[Q45tech]

I have an excellant memory for a 60 year old [and went back to school at 50 for another 4.00 Masters Degree ] Plus I ASK all the technicans from 3 shops what they find as to Q problems.

After looking at or discussing thousands or so Q over 18 years.The statistical frequency of EVERY FAULT becomes known.Just as we can view the average cost of Q repairs [parts vs labor] on a monthly or annual basis back to 2000 [new software]. We can look back 8 years and see each owners expentiture and what was recommended vs what they actually had repaired.How I know the average Q has >$3,000 pending and unrepaired when they sell or move out of our area.

I probably don't have as much data as Nissan does in Japan* but surely more than any Single US dealership since after warranty the visits really drop percentagewise.

*Nissan knows the sales rate of every parts sold vs what is in inventory in warehouse and at dealers. Failures per thousand units is the usual format.

[jimbyjimb]

I recently discovered the noise comes from both sides, the right side being the more common source. Being that cat heat shields are suspect according to past posts I am going to completely remove them to see if that cures it. The first thing I do when I go under the car, for several weeks, has been to check the heat shields, and so far no noises and all is tight, but what the hell. I've ruled out the rear as the source, it sounds as if it is coming from the underside front/middle of the car, almost where the cats are, so again, the common cause of the rattle is pointed to. I just wish I could manually re-create it. The front end is going to be getting a very in depth look over this weekend (Monday/Tuesday). She's been running a bit rougher than normal lately so I need to play with the IAC a bit anyways, and take care of a few other little odds and ends. Thanks for the input people, really appreciate it.

[Q45tech]

Over 15 years T3 must have used 1,000 hose clamps to fix rattles in heat shields whereas the non experienced remove the heat shield and subject the Q to potential grass and leave fires.

[oldmako]

Can you get a dude to stand IN the trunk and bounce the car up and down HARD while you slide under it on a creeper?? Put my big fat a$$ in that thing and I bet that noise would show up again.

[Q45tech]

Why we use 2 [TWO] techs one to drive and one in front, then rear, and trunk if necessary with stethoscope. Also we have one walk beside the vehicle in a quiet parking lot.

Drivers [owners] without trained family members and friends or who don't want to pay for help are often at a disatvantage.

[paranoidjack]

Why we use 2 [TWO] techs one to drive and one in front, then rear, and trunk if necessary with stethoscope. Also we have one walk beside the vehicle in a quiet parking lot.

Drivers [owners] without trained family members and friends or who don't want to pay for help are often at a disatvantage.

As logical as this sounds, I can't help but chuckle at the thought of a disgruntled customer paying $75/hour for premium techs and watching them walk alongside the car outside...

The leg bone is connected to the, wish bone....

[AlabamaDan]

...Shame on me. I altered the original equipment on my 9 year old 4500 dollar Q. I also neglected to spend 8 hours under it last month. And to top it off, I only opened the hood once in June. Sorry to degrade the brotherhood in such a despicable manner. ...

Someone put him on double secret probation and take away his secret decoder ring!

[oldmako]

By way of penance today I (finally) installed my transmission Cooler and did an oil change. I also removed and repainted the upper radiator brackets as they were corroded and looked like hell.

I managed to get the cooler in from above and left the rad in place as well as the shroud and the engine driven fan. The only thing I removed was the upper rad hose to facilitate leaning the rad aft to slide the cooler in. All in all pretty easy although there was some cussing due to the fit of the old hose and the new. I ended up splicing them with some copper tubing. A better option would have been to buy several feet of hose and just replace all of it.

Car happy now.

[AlabamaDan]

I say check the brake pad clips. I think I have the same problem.

[jimbyjimb]

Yeah, I solved a friends rattle on his 300Z because some bonehead used cotter pins on the locater rods for the brake pads. That cracked me up, a 10 dollar set of pins and a spring fixed that. On Tuesday I did a 60 mile bike ride so when I got home I didn't feel like playing with the Q but sometime soon the front wheel are coming off along with much of the exhaust heat shielding. Not too worried about brush fires in the middle of the nation's 19th largest city and probably the rainiest in terms of days of rain. My Q and I don't make it off road as much as we used too... Just kidding in good fun of course! Anywho, I don;t see how it could be anything but the shielding even though I can;t make it rattle, there just isn't anything loose down there that would do so, pending the third front-end inspection in a month that is.