Originally Posted by
datlas
Dumb car questinon:
For the past week or two, I notice the Saturn is shuddering while coasting. It's fine and smooth when I give it gas or pop into neutral. It idles at rest more-or-less ok, with a little up/down in RPM 1100-1300.
My best guess is whatever controls the engine at idle is giving a little more/less fuel causing the shuddering when it's in gear and coasting.
Comments?
I would start by trying to find out why it's idling so fast. Might have a vacuum leak. Normally problems with the way the things run isn't going to affect deceleration but if the idle is surging you might feel that.
If by shuddering you mean like a mechanical vibration that sounds like a transmission or final drive issue. Maybe even a motor mount. Even a timing chain. Check for a vacuum leak first to try and get the idle squared away.