I have a 2000 Buick Century with a 3100 in it. Sometimes when we back out of the driveway, the engine shakes a bit and rumbles (like we modified the exhuaast)...but once we put it into drive the engine calms down and the rumble that was there also stops. This is very intermittent.

The car has 60,000+ miles on it.

Other times we'll be driving and we'll notice the engine sounds rough (no shaking though).

Anyone have any ideas on what might be the problem or what needs to be done to have this problem fixed??

Thanks,
krfan1

what are you? some kind of idiot? these aren't automotive forums...go troll somewhere else



IBTL

This thread is worthless without pics!!!

First, go some place like Auto Zone or O"Rileys and have them run a computer scan. They will do it for free.

Possible problems, O2 sensor, or just a cleaning of the injection system.  Tune up may be needed. .. fullclip

Have you checked to be sure the plug wires are secure?

I had a very intermittent rough running 3.8L in an Olds because #5 plug was not fully seated.

Is there a pattern to the fault?

For instance:
time from start
ambient temperature
engine load
fuel level
etc.

Any codes set?  Have the auto parts store do a diagnostic scan and see if there are any fault codes stored in memory.

Visually check obvious things like plugs, plug wires, all engine management connectors.