Sudden Rough Acceleration & Rough Idling

engines

#1

The other day I was driving my 1995 Saturn on the highway and it kinda bucked for a second and I thought that it was odd. A day or 2 later it started accelerating and idling rough. It was rough enough that I immediately called my mechanic wondering if this was a sign of the timing chain going bad. It has 123k on the motor- timing chain has never been changed. He guessed it might be a motor mount that went bad on it- It is in the shop but my mechanic either hasn’t looked at it yet or hasn’t come up with a diagnosis. Any thoughts would be appreciated.


#2

This could be something simple like a disconnected or cracked vacuum hose, or it could be any number of more expensive fixes. Only someone who can examine the engine can determine the actual cause.

What can you tell us about the car’s maintenance history?
Specifically, when were the spark plugs, air filter, and fuel filter last replaced?


#3

It’s close to due for a 30,000 mile tune up. I was planning to get that done before winter sets in. It’s probably been about 3 years since I had all that done as I don’t put a lot of miles on the car.


#4

Yeah- it turned out to be a fouled plug- My mechanic replaced the plugs and the fuel filter and it is running ok now.


#5

I might suggest that you check the owner’s manual and see if yo are behind on any other maintenance items. Delaying or ignoring maintenance is the most expensive way to own a car, except maybe leasing one.


#6

Using a mechanic whose first guess as to the cause of rough acceleration being a failed motor mount is probably not cost effective.