Hello. I've had an HS250h for just at two years now with no problems but in the last two months or so we've noticed that every now & then when I start the car there is a hard shake in the engine, maybe for a second and then it stops and drives fine. It seems to be tied to weather changes and coming off a cold temp or going into a cold temperature outside. It has gotten more frequent, 2x this week. I haven't had the spark plugs changed yet. Had the oil changed in November which is about when it started.

 

Mine does this every time it's really cold. It's in a garage where the temp might dip to -5 F on nights when it's -30 or colder outside. That's in northern Minnesota. Probably doesn't get that cold in Indiana.

 

Don't know your mileage but it could just be the cold. However, changing the plugs on this car took me 20 minutes in my driveway. Also check your oil level as it tends to get rougher running when it gets low and these motors have a bad rep for eating oil.

 

Not so sure that it's the cold. Mine has done this a few times and where I live temps go down only to the low 60's F.