Yeah, could be the upper mount, but this usually has the engine moving too much and thus a thump or surge forward or backwards when you first start off, either going forward or backing up. Look under the hood in front of the driver's side and you'll see an extension out from the firewall with a round ring on the end. the round ring has a rubber circular rubber bushing in it with a long bolt running through it that's attached to the engine. Visually inspect the rubber bushing. If it doesn't look broken, try grabing the circular metal part and push it and pull it to see if there is excessive movement. Hope this helps. You'll know if it's not good. That's your upper engine mount.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.