Driveline whine?

[duste]

Okay, so I replaced the front and rear engine mounts in my N/A TX3 (east-west engine) this afternoon. It now has a very pronounced driveline whine and I have no idea how simply replacing the engine mounts could have caused this?

Annoying the shit out of me already and I'm tempted to just put the old ones in again.

Any help is greatly appreciated, semi-urgent.

Thanks.

[Fukushima]

I have no idea how simply replacing the engine mounts could have caused this?

if the motor and box have moved slightly the cvs may have shifted

is the car lowered?

[duste]

The CVs are brand new, replaced just over a week ago. Had another much closer look today and both left and right mounts were also gone so I've replaced them with brand newies.

Gearstick slop is all gone now but that whine and vibration at 3000rpm is still there. FFFFUUU!

I think the front springs may be lowered slightly - they're the original ones from my Turbo TX3 and it was always quite low at the front.

Reckon if I take it back to the CV shop they'd be able to fix it if it is to do with the CVs? I've noticed the whine is only really in first gear, but the 3000rpm rattle/vibration is in every gear.

[Nic_A31]

sounds like new mounts are holding the motor and drivetrain a bit firmer, so whine in first would be more pronounced (gearbox isnt moving around as much as before), as for the vibrations, that could be another story, just make sure axles CVs and mounts are all lined up straight?

[Joe]

I'd say your old engine mounts were so worn out, that you couldn't feel or hear the driveline vibration previously.

Now that the engine mounts are in better condition, the NVH is being transferred through the car.. same deal as when you put stiffer poly bushes in a car, or poly engine mounts/transmission mounts, you get more NVH.

[duste]

So is the whining or vibration something to be concerned about?

[Joe]

Vibration at a certain RPM could be dodgy gearbox output shaft bearing or one of the driveshafts.

Whine would just be NVH through engine mounts.

[duste]

Aiight well can't be there driveshafts because they're brand new with the CVs.

Just checked gearbox oil...seems Mr. CV man down in Thornborough Rd didn't top up the oil when he did the CVs.

[mitchy]

Aiight well can't be there driveshafts because they're brand new with the CVs.

i wouldn't be assuming anything...

[duste]

Considering how much the fucker charged he would have wanted to have put brand new shafts in.

[VT SS]

Aiight well can't be there driveshafts because they're brand new with the CVs.

Just checked gearbox oil...seems Mr. CV man down in Thornborough Rd didn't top up the oil when he did the CVs.

Noise gone after you topped up the oil ?

[joshg123]

Does the car make the noise at 3000rpm when stationary in neutral? I think it will... So grab your jack and put some load under different points of the engine..... Either Youve bolted the engine mounts up and something is just touching a crossmember or the side mounts have collapsed.

If the noise is there in every gear, but more pronounced in first its a harmonic thing, not a driveshaft related thing.

[duste]

The noise didn't go down after I topped up the oil, no.

And nope, no noise at 3000rpm in neutral, smooth as. All the engine mounts are brand new, so they can't have collapsed already, but I'll have a looksie with the torch once I get the car up on stands and see if anything is touching the cross-member.

Thanks guys, trying to get this sorted as I'm planning on selling it off asap.

[duste]

Alrighty, turns out the cross-member was slightly bent and as a result the gearbox was touching. Replaced with my old one and the vibration at 3000rpm is still, but the whine still persists. :(

[duste]

Anyone ever used Nulon G70? I'm thinking of giving it a go to quieten it down.

[duste]

Bit the bullet and poured some Nulon G70 in to the mix, but I've read it can take up to a month or two to take affect. Fuck.

Oh well, hopefully it does work eventually.

Thanks for all your help guys!