Hi im new to the site and i need direction.

 

I have just purchased my first nissam 300zx non turbo import

its done 33,000 miles with 17 inch split rims.

 

Heres the problem......i have a loud humming noise coming from the rear of the car......!

 

I have had new wheel bearings and a new prop shaft with centre bearing.....still no luck.

 

Today i have had new tyres tracked and balanced but stilll no joy.

 

I was wondering if it could be the diff bearings??????

 

Could anyone help me! please?

From what you say thats sounds like all thats left. Does it change with power on/off? If it does thats diff to my old ears. If it doesnt it can be the bearings in the diff. IMHO

Hi Mark,

 

I have the same problem , can you clarify for me what it could be as the noise changes , depending on your speed.

sorry to butt in but its been bugging me for a while now ?

 

Kev

It could be the diff itself although that would seem pretty unlikely.

Diff bearings - maybe ...

Fuel pump can make some funny noises

A humming fuel pump is very common. Do you here a similar kind of hum when you switch the ignition on and off (as the fuel pump pushes petrol up to the engine before you start it and back after you switch off)

 

If it is humming then its probably starting to die(common fault)

 

Cheerz

 

andy

Is it a noise, or is there any vibration with it too??

 

My previous zed had what was more of a noise than a vibration comming from the back though as time went on it got louder and began to vibrate, when i ran the car on axle stands i found that one of the driveshafts leading to the wheel was spinning in almost an elipse. So thats what i had , a knackered driveshaft, or one of the bits it attaches to.

 

Might be worth running it on axle stands with the wheels in the air, then again with the wheels off, see if that narrows it down a bit, having said that, i was told it was possible to cause damage this way (not to mention being bloody dangerous!!) so get someone else to confirm this before going ahead.

 

Good luck, and hope the problem is an inexpensive one.

Could actually be the diff bushes. If they are excessively worn they may be transmitting vibration to the car. If you are going to run it with the wheels in the air, then make sure the wishbones are taking the weight of the car and are not 'drooped' as this will cause excessive wear in the driveshaft UJs.

 

HTH

 

CheerZ,

 

Andy

Thanx Lads

 

I have slight vibration in the seat but i am going to try it in the air

to see if i can hear anything or see anything...just been quoted ..second hand diff £275 +vat delivered or to have mine reconed ...its about £600 so if there are more options please let me know.

 

Thanx

Check theres oil in the diff also and no signs of leaks. At 33000 miles it cant be wore out. Mine is silent with 130000!

Cheers mate.

 

Theres no leaks very slight play not enough to make a difference had oil replaced.

 

I AM AT A LOSS

 

I dont fancy spending money on the diff though its a bit drastic!

 

Thanx

 

Lee

My Fuel Pump sounded like this. Then it started buzzing around 3000 revs...

Ive tryed to go fast, slow turned left then right ,braked sharply but the humming does not vary only slightly and i mean slightly at speed.

LOL its not the fan above your head is it? If your car has aircon there will be a fan above your head in the centre - these are prone to bearing wear and can hum. Maybe you don't have aircon but was just a thought ;)

 

CheerZ,

 

Andy

If you have standard wheels could you try the fronts on the back?

Further to my last I just mean to see if the noise changes etc. Not for good.

Andy

 

How much for a Fuel pump ( new or S/H )

 

kvkev

Thanx For the help Everyone!

 

I have air-con but the sound is to violent and to deep i have even tryed it in gear and without. There is now a noticable vibration in the seat though....any thoughts?

 

Im going to try the tyres.....cheapest option....then the dreaded diff bearing or bushes or whatever the hell it may be!

 

I cant try swapping the wheels because ive got split rims and the rear ones are wider than the front....im going to see if i can flag someone down with one and pay them to see if i can swap the backonesfor 10 mins.....only problem with that is there is only one other in this area ( I think ).....Derbyshire out in the sticks abit.....

 

 

That company says that they will do whatever for £350 (recon) its looking like that to me.

 

Thanx

 

Lee

If its the tyres and who knows from here, they might be falling apart, hence the recent increase in vibes. A bearing is not going to get much worse over a long time. I had a trye go on me and it fell to bits very quickly, and I thought that was a bearing until it shook the car to bits. Also if it that bad you should see some hint on the side wall, in or outside.

There is no visible signs......but tyre man says there maybe a bobbling in the tyre itself....im going to have them changed in the week.

 

Thanx

 

Lee.

I've also got a humming noise ever since fitting poly bushes all round, but it only makes noise on slow down and very slow acceleration, so have to keep acceleratng hard.lol. Seems strange that diff bearings should suddenly go just when out so figered it is something else.

Are you sure your noise is not the gearbox? Think mine might be. My first one never had any oil when it was brought into the uk so wore out pretty quick. I should check all the oil levels!

Yeh! maybe ........ dont think ive checked that and theres a slight cluncking sound in changing into 2nd but only when its cold so we shall see.

 

Cheers mate

 

Lee

RIGHT......

 

Tryed the car in the air the sound is still there its got to be the diff.......Bastard....

 

Does anyone know where i can get a diff from?? or someone that will recon it .

 

Dont want to be paying more than £250 for the diff really but i need to know where i can take it.

 

Help!

 

Lee