My 1993 940 wagon has gotten quite loud of late with what seems to be engine noise in the passenger compartment while underway. This has probably crept up over the years as, until my daughter went to college, I rarely drove it. It is obnoxious at WOT or road speed requiring > 2500 rpm. It is not exhaust noise as the entire system is new with no leaks. There is a resonant vibration quality to it that leads me to believe it may be that the hydraulic mounts have collapsed, transmitting vibration through the mounts to the chassis. Consistent with this is the fact that, at speed when going over bumps that cause the car's suspension to rise, the droning sound goes quiet, I'm picturing as the load lifts off the mounts. They are not torn nor do they have any visually observable defects.

I was reluctant to spend the money on new mounts as a diagnostic but was willing to chance trying some very cheap aftermarket replacements (Uro brand, ~$24 each). Either my theory is off base or these Uro mounts aren't really hydraulic mounts, but rather, solid rubber look-alikes that transmit as much, if not more, vibration than the 245,000 old OE ones. The only thing that is different is that the fluctuation in sound over undulating surfaces is gone. The new mounts were about 1/2" taller than the old ones so the old ones may be somewhat collapsed.

Any thoughts on this are welcome. I'm about to complain to the vendor about the Uro mounts and will probably just put the old ones back for now. If the solution is more money for a better mount, I'm game but I'd feel better about trying it if someone else had a similar problem that was resolved with new mounts.

TIA