While waiting at a light, I felt a vibration I hadn't noticed before. It was a constant vibration like any engine vibration, just a bit more than normal. I slipped the shifter (auto 4sp) into neutral and it smoothed out. This was my wife's car and I'm still getting used to it, so every little things catches my attention. It has 160k miles and is due for a trans flush/fluid change. Any other suggestions?

How is the car's state of tune?

If it is in need of a tune up, it could be running a bit rough and putting it in neutral (taking some load off it) would allow it to be a bit smoother,

What does your wife say about this?
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'96 855R,'64 PV544 driver, '67 P1800 basket case, '72 Yamaha Rd400, '68 Honda 350-4, '12 XC70, the first 5 are mine, heh, heh, 525,000 miles put on 10 bricks James A Sousa

The car seems to be running great for 160k miles. I'll check the mounts.

I was afraid I had some trans problem. Then a few days later the red arrow came on the and I was really scared until I realized that a large jar of peanuts had put the trans into winter mode!

I would check the motor mounts, the one on top of the engine and the other on the passenger side, just below and to the rear of the crank pulley.

There is a tranny mount, but that dosen't fail that often.
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My name is Klaus and I am a V♂lv♂holic

I agree. Sounds like engine mounts. My 95 has the sort of problem. I am about to replace both.

At first, I thought it was just the upper mount. Upon further inspection I discovered that the lower was bad and is the real problem. If the lower mount is bad, the engine can shift around and can cause an vibration as it has done in my car. If it is really bad the engine is basically sitting on the subframe hence the vibration.

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95 855 GLT Sportwagon 214k, ex - 90 244 DL 300k