Hey everyone. At idle, every 5 seconds or so the engine will shake, and I can feel it even more through the gas pedal. At that same time the RPMs drop 100 or so, then go back up. The oil pressure gauge drops at the same time also.

And, I was driving across an intersection today, and it felt like my car had no power. It felt like it was struggling to make it through. Any ideas?

Tune up time.. Plugs,Wires,Air Filter, Fuel Filter,o2 sensor,PcV valve. Do all these things and also put some mystery oil into your crank when you change your oil and in your gas tank just to clean fuel system. I had an idle prob and doing this not only saved me $ in the long run by having more MPG it sure made my car run a whole lot better.

Thanks a lot! will do.

Ya mine kinda shakes too about every 3 seconds at idle (very slightly), not sure what it is, probably something internal that I should be worried about but...I asked a mechanic and he didnt know what sound or shake I was talking about and couldnt locate it.

Probably one of my injectors are a little dirtier than the other or one of my coil packs are going bad, because the engine runs like its brand new when its driving.

Yeah, and we all happen to have '93 Bonnevilles, I have 175k on mine.

I had the same idle shake problem on my car (also a '93). While going through it to fix a missing problem, I noticed the idle problem disappeared. If I remember correctly this idle problem (not the miss) dissappeared after I changed a bad cannister purge valve.

I would still do a full tune-up first.

How much does that canister cost..... I noticed mine is kinda ghetto rigged, the charcoal canister that is. I cant even find a way to secure it, its just setting there. Can you post a pic of what yours looks like so I know how its supposed to be in there or just describe its setup?

I think it'* usually clamped down by its bottom edge. There'* a round fiberglass filter that goes in the bottom (which no one ever replaces).

If you can lift yours up, do so. Turn it over and see if the filter is in place on the underside. Look for a loose clamp somewhere down there that should have been holding down your canister.

This is all from (foggy) memory; if someone else is closer to their car than I am right now (downtown Chicago), they can tell you better...

Well I can see that there is a clamp hanging over the canister on the front but it isnt attached to anything, nor can I find anything to attach it to.

I'll take that sucker out and check it

On my car the cannister is buried underneath the winshield washer fluid tank on the driver'* side. It'* hard to see it unless you move the washer tank.