About 6-7 months ago I installed some Urethane motor mounts as I was getting tired of replacing worn out OEM mounts. First day the car was vibrating so badly my teeth were chattering, worse when in gear at a stop. Took the car out for some serious high speed assaults on local highways and expressways every day for about 2 weeks. The serious heavy vibrations stopped as the mounts "wore in" and only experience any vibration now when I start the car first thing after sitting a day or two. And sometimes a brief "rasping" when I take off in 1st gear. Once past 5-10 MPH and beyond it smooths out and purrs like a kitten and gets as smooth as silk. I especially like the tight feel of the whole engine to drive train to rear wheel response with these mounts when accelerating, changing gears and cruising . Really really very good at moderate to high speed driving, in fact I would go so far as to say excellent. My only concern is the slight vibes I feel when starting her up and sometimes sitting in traffic while in gear. Any thoughts on this?? Am i doing any damage to any other areas of the car or should just keep on and just "get used" to this little idiosyncrasy and see if the vibes stop altogether over time? As I said before, once at speed she smooths out fine and at even higher speeds or accelerating it feels awesome. Thanks for the read and any serious responses.

 

What you describe is normal. When I filled my mounts with 80A urethane, NVH increased at idle and low RPMs. It is probably worse in cars with auto transmissions.

 

Well what mounts are they? Not clear of they’re filled OE mounts or aftermarket?

you might check to make sure one isn’t broken, but more than likely low compression at idle.

 

STEVE Thanks for the reply. I thought so just wanted to check. these are what I installed ( the softer S' street" versions )

https://www.rx8performance.com/products/motor-mounts-1

 

TEAM RX8 -- Thanks they are NOT filled OEM mounts. One is not broken, I have my mech check them every time I bring the car in for service or some other issue. as of last visit about 2 months ago, all was well. These are the solid urethane mounts I have installed , softer street versions,
Thanks again!
https://www.rx8performance.com/products/motor-mounts-1

 

I never heard of them offering a softer version. Are you sure?