My 2004 Toyota Highlander starts to vibrate/shudder on a cold start.

Someone else just the other day had the identical problem. The bad thing was they said "vibrate" instead of "skipping". Everybody chimed in on what to check to remedy the "vibration". The whole time it was bad plug wires or a coil pack. They didn't specify. So is your vehicle really vibrating? Like the steering wheel is shaking, or the tires sending a vibration through the steering wheel and floor boards? Or is the engine "skipping". Like it loses power and bogs down in very rapid spurts, then smooths right out?

It's more like "shuddering" and it doesn't seem like the engine is losing power, although I am hesitant to really gun it when it does this. It actually makes a noise like it's vibrating. It started out doing it a small amount but it's getting worse. My mechanic is going to test run it tomorrow; he thinks it's plugs and/or wires like you mentioned. I'll let you know. Thanks for the answer.

If it isn't spark related, the only thing I can think of that vibrates at a certain speed would be the CV joints. Possibly one of the boots has split and lost all of it's grease.