hi all - having some trouble tracking down a persistent vibration in my 90 740t (340k km) - it occurs most noticeably around 2000 rpm regardless of speed and has been around in varying degrees for more than a year and 20k km now

initially thought that it was the exhaust as it was literally falling apart - totally removed the entire system from the turbo back, re-welded the cat back onto the main pipe, replaced rest of exhaust with scrap parts that still have lots of life left - all hangers were in good shape - replaced entire system, checked for leaks (none), nothing touching under-body, tightened pipe at turbo - still experiencing vibration

there has been no noticeable change in performance, gas mileage or any other parameters - changed the t-belt about 10k km ago, no change in vibration

i have owned the car for almost 3 years now and her tranny has been sloppy the whole time with rather harsh shifting - checked and replaced fluid levels and there is no noticeable change in shifting since this vibration showed up

my thoughts now are that it could potentially be engine or transmission mounts which i am going to check this weekend - is there anything else that i should be looking for?

replaced both engine mounts and tranny mount - she's like a whole new car! i ordered the mounts from FCP Groton, time will tell if they are decent

Which mounts did you get? I've read here warnings to only get the expensive genuine Volvo parts because the cheaper aftermarket ones aren't very good. I had been experiencing an annoying vibration in Drive while sitting at traffic lights and presumed it was worn out engine and/or tranny mount, so got the cheap ones from FCP Groton. However, they're still sitting in a box because when I had the header pipe replaced (welded solid to the cat because the flange was shot)the vibration went away.
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1992 745 approaching 500k km

got out a pry bar and did some investigating over the weekend - looks like i need new mounts, both of them are shot - been doing some investigating for replacements and don't really want to pay huge $$ as she is just my daily commuter/packmule - found some mounts from a company called FEQ for a reasonable price on autopartsway . ca - anyone ever use these or similar??

If your mounts get bad enough, the transmission touches the cross member.
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'96 855R,'64 PV544 driver, '67 P1800 basket case, '95 855, '95 854, the first three are mine, heh, heh, 485,000 miles put on 9 bricks

The motor mounts can sag so the oilpan can touch the crossmember. On the trans, that mount can collapse and the trans tail can hit its support.

So you can sit in the driveway in neutral and rev to 2000 and it does it?
If so, motor mounts is my guess. Check your mounting brackets for alt/compressor/power steering pump. Had power steering pump bracket break, and a bolt sheared off the compressor.
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