urethane mounts advice

[E30 Wagen]

I thought I'd try the urethane set from AKG for both the engine and the transmission, and while the shifting is unbelievably better, the vibration and noise is not acceptable, so much that I think something is wrong with how my engine is running. My engine has never run very smoothly or strongly, so I'm wondering if that could account for the major noise/vibration increase via urethane motor mounts? It's really bad during acceleration. Of couse I anticipated an increase of this but it really caught me off guard on the drive home from the shop, like a lot. It suddenly sounds like my exhaust has rusted off. I'm thinking about re-replacing the motor mounts with stock rubber but I want to keep the urethane on the transmission because it shifts so well. Can I run the stock rubber motor mounts along with urethane transmission mounts?

Or, should I be more concerned that the vibration and noise is now actually coming from the transmission?

[Garageaholic]

Yeah, the stiffer mounts do transmit alot more vibration to the subframe/frame.. If you could live with it, i say go with it.. I dont see the advantage of doing one urethane, the other rubber... but if that's what u like, then go for it..

personally, i say all urethane, or all rubber, to keep it uniform

[rwh11385]

both you have the wrong idea.

urethane motor and bimmerworld upgraded tranny mounts. almost all the benefit, without much of the NVH cost.

[Garageaholic]

would you notice a big difference between the bmrworld upgraded tranny mounts and the urethane mounts??

[rwh11385]

i barely notice a NVH increase from rubber to urethane engine mounts (just a little... some more at idle, some more sound transmitted, but not bad). Only really difference in BW mounts was the knob vibrated a little more at idle.

but the BW mounts did help in shifting.

[E30 Wagen]

i barely notice a NVH increase from rubber to urethane engine mounts (just a little... some more at idle, some more sound transmitted, but not bad). Only really difference in BW mounts was the knob vibrated a little more at idle.

but the BW mounts did help in shifting.

I'm getting a lot of vibration. Like, a lot.

Could it be my engine running like poop?

And if anybody can answer my question, is it bad to run one rubber, the other urethane?

[bala_eos]

both you have the wrong idea.

urethane motor and bimmerworld upgraded tranny mounts. almost all the benefit, without much of the NVH cost.

Is the Bimmerworld transmission mount rubber or urethane - their website doesn't mention the material.

Thanks,
Bala

[rwh11385]

Rubber E21 mounts. But they are GREEN!

You'll need to thread them into the tranny bracket, and buy hardware (nuts) from Lowes.

[Axxe]

My IE motor and trans mounts barely transmit more vibration into the car, while giving me presice shifting and immediate throttle response. It's great.

[E30 Wagen]

Okay, I drove around a bit more today, and it sucks. Something just isn't right with either my tranny or my engine or my mechanic did something horrible. The vibration is crazy loud. I'm going back to rubber...

[rwh11385]

Okay, I drove around a bit more today, and it sucks. Something just isn't right with either my tranny or my engine or my mechanic did something horrible. The vibration is crazy loud. I'm going back to rubber...

r3v answer...


if you have a serious vibration problem, going to rubber is just trying to ignore it...

[E30 Wagen]

Well, the vibration wasn't there before.

I probably should have kept the more expensive IE mounts. THey looked a little better quality than AKG.

Or just gone with more practical rubber... Like I even need urethane anyway. I'm a moron.

[rwh11385]

maybe you're misfiring or something, have a driveshaft with a CSB going bad, or maybe you just didn't feel it before

anyway, cheap urethane on a daily probably not a great idea.

good luck