strange engine noise

[andyli]

dear guys, My 91 vn v6 has just been chnaged engine oil for two months but when I accelerate between 30-60km/h, there is a laud noise, low frequency. could this be a engine problem or the transmission?

[cruzncommo]

where does it sound like its coming from and is there any vibration? it could be an idler pully, harmonic balancer, water pump, alot of things. if theres vibration its more then likely transmission.

[andyli]

hi, thnaks for the quick response. the harmonic balancer and water pump is brand new. I do not think it is with viberation. is this the puly? how much does it cost and could I just leave it like that.

[88GreenVN]

If its a hollow metallicy sound it could be the timing chain/tensioner. It makes the rattley sound under light load in the mid rev range.

Or the little pully on the belt tensioner.

[andyli]

you are probably right. it come out when there is a load but when it got the speed of 60 and up it disapear. would I just ignore it or spend some money to fix it.this bloody commy ask for 2 or 300 bucks every 2 months.

[pandaman]

So what kinda noise are we talking here? Is it a clunk, a grinding noise, a clattering noise? Some better description would be good, these old motors make a lot of funny noises,

[andyli]

it is a low frequency hollow sond, not a rattle but constant, when it rev up to 60km/h it disapear.

[rredbeak]

If the noise is speed related its probably gearbox...

[pandaman]

If the noise is speed related its probably gearbox...

Not necessarily. I'd say that if it's speed related it's likely to be drivetrain, and there's a whole lot more that can go wrong in the drivetrain than just the gearbox, could be tailshaft center bearing or a diff problem just for starters.

[88GreenVN]

it is a low frequency hollow sond, not a rattle but constant, when it rev up to 60km/h it disapear.

I'ts probably the timming chain if its a hollow sound that fades as the load comes off the motor.

[andyli]

thanks for that. I checked my transmisson oil today found it is too much there, when test it hot, it seems twice as it should be there, could this be a reason for the noise? I do not want to spend money on this VN any more, but some times It is really reliable if you put 300 bucks every two months for repair.

[andyli]

hi, guys, sent the car to my mechanic, test drove, said it was the drive shaft. I doubt it, could that be too much oil in the transmission or really the shaft? how much would that be?