Engine vibration - mount replacement

[Dennis Kalma]

Hi there again, the paranoia continues!

Anyway, working on the '75 Kremer, I have a bit more vibration in the driveline at higher (>4000) rpm, thought was to replace the engine mounts as the ones that are on the car are about 30 years old now.

Anyway, got two new Porsche ones, question is, should I start with the two mounts in the engine compartment first or the transmission mounts? I figure that the engine compartment mounts would be most influential in engine vibration, being closer and all....but anyone have any ideas or even experience in it?

My thought is to replace two...if the problem goes away, then great, if not then I'll probably replace the other two.

Thanks all...

Dennis

[911Velocity]

Originally posted by Dennis Kalma
Hi there again, the paranoia continues!

Anyway, working on the '75 Kremer, I have a bit more vibration in the driveline at higher (>4000) rpm, thought was to replace the engine mounts as the ones that are on the car are about 30 years old now.

Anyway, got two new Porsche ones, question is, should I start with the two mounts in the engine compartment first or the transmission mounts? I figure that the engine compartment mounts would be most influential in engine vibration, being closer and all....but anyone have any ideas or even experience in it?

My thought is to replace two...if the problem goes away, then great, if not then I'll probably replace the other two.

Thanks all...

Dennis

Replace all with fresh polyurethane mounts, not solids.

Best regards,
Gerry

[DW SD]

I replaced all four in about one hour. They are very straightforward. Why not do four and let your paranoia have a break?

Doug

[drsimonwong]

Do all four. Go with at least the sports cab version, or if you don't mind a bit more transmission noise, the wevo's.

Will tighten up your shift noticably.

Simon

[Cookie Porsche]

Do a board check - similar thread subject elsewhere.

No extra noise from the Wevo - in my mind.

Looking at your cars I'll most definitly recommend something a lot stiifer than std - even solid rear and sport type by gearbox.

Vibration at rpm is normally NOT engine mounts, rather check elsewhere. I find that the solid mounts are a little ratty at idle/low rpm, but fine once you get going.

Tom

[Dennis Kalma]

"Vibration at rpm is normally NOT engine mounts, rather check elsewhere. "

What things come to mind for checking vibration? The engine was very smooth when I got it a number of years back, so the major parts are fine....could it be things like the cooling fan or clutch/pressure plate assembly? Can't thing of many other rotating parts that would make any difference at all....and even the fan and clutch assembly seem to be too small/light to make much of a difference?

Thanks again...

Dennis