Problem with my Cavalier, anyone know what?
 

I was drivin' around one day and noticed that while I sit in my running 1999 Cavalier, at a stop light for example, it sort of shakes or vibrates randomly. It's sort of like feeling a bump... bubump... bump bump BUMP bubump... lol. So I took it to the mechanic, and he said that my coils probably went bad. So he replaced them and the car was fine for around 3 weeks. Then, the same thing started up again, and a couple days later the "check engine" light came on. Before I take it back to the mechanic I'd like to have some sort of idea what the problem might be, just so he doesn't give me a line of bull. Thanks for any suggestions on what could be the problem!

first off which engine? 2.2L or 2.4L twincam
Second which trnasmission? 4 spped auto or 5 spped manual
Third how many miles?
Forth have the plugs ever been changed?

your would be equipped with 100k mile platinum plugs, that most likley are carbon traked along with the wires. one bad coil i could see, but both i would doubt. if the check engine light is blinking then it is a ignition related misfire. rough idle is often caused by carbon build up in the throttlebody and the fuel injectors getting gummed up. without actually having the DTC that is currently set, my only adivce is that you are most likley due to for a tune-up.

It's the 2.2L automatic. It has 64,000 miles.

your fuel injectors could be clogged, u might want to try some injector cleaner of some sort. like stp or another kind.

i have had a couple of those in the last couple of weeks that leaked antifreeze fromt he headgasket onto the coils and made them misfire.

so are u sayin the headgaskets shot? ouch that sucks.

those motors have bene known to develop an external headgasket leak. more of a watch the coolant level type of issue. rarely does it form a milkshake int he oil.

I was thinking the same thing....thats why carbs are better :D

carbs are nice, unless u want to like.......go on and extreme incline/decline, or run turbos (usually a shitload harder on carbs), or tune with a computer. I personally enjoy tuning with a computer, and forced induction. Carbs have there moments tho, something about being able to hand tune a car with not much more than a screwdriver is appealing.

I may only be 22 but I like the classic way screw driver and some gas is all you need, leave the computer at home!

if it's vibrating at stop but in gear....sounds liek atranny issue.....like torque converter or something else. you got hosed into buying new coils though!

I don't think so. It fixed the problem...for a short time, but longer than a week. If he's got a leaking head gasket, and that caused coil failure as is possible, as was mentioned above, then he may be out for a head gasket AND another set of coils.

All I can say is: "Damn... I'm so poor."

A cav with a blown head gasket already....wow never knew a chevy to have that happen at such low mileage.

there could be special circumstances, we dont really know the whole life of the car. Somethimes stuff just stacks up and headgaskets can go at lower miles.