Intake leak?

I have a 99 malibu 2.4 and i now noticed white smoke from the tailpipe,checked the oil to see if its milky and it doesn't appear to be,its idling rough and hesitating pulling out but it runs fine down the road, my question is if the intake manifold (head gasket)is leaking will it cause the rough idle but yet run fine above15 mph?:banghead:

Could be your ignition pack.

I replaced the coil packs,fuel filter,iac sensor,plugs and cleaned 02 sensor .The oil looks alright but it has very strong smell to it and if your back by the exhaust while its running,your eyes are watering. I assumed if it was head gasket leak it would run rough at idle and also above15mph, but thats not the case, its just when its idling. Any opinions?

White smoke = steam = water/coolant in cylinder = head gasket.

My :2cents:

-Mark T.

I didn't notice the smoke until after i had put the dry gas in and a bottle of fuel injection cleaner to a half tank of gas, it couldv'e been smoking before that but im not sure ,its not alot,could this explain the smoke and very strong exhaust fumes?

Well start at the beginning. Do you have CEL?

Either way, pull codes.

-Mark T.

cel?? My check engine light has never came on, but i had it scanned anyway and of course nothings comin up.

Sounds like you covered a basic tune-up..
you didn't mention plug wires.
check pcv for the hell of it.. I had one gum up on another vehicle.. gave me a touch of a bad idle.
fuel injectors?

just my thoughts.

-Mark T.

Are you referring to the boots as plug wires,cause there is no plug wires from the coil, and no i haven't replaced them. And the 2.4 doesn't have a pcv valve ,i had to call the dealership to find that out,nor does it have a egr valve.The fuel injectors were checked when i had it at the shop to have any codes read. Im boggled!

Oops. Selective reading helped me miss the 2.4L detail.

Bad gas?

-Mark T.

*edit -- check for vacuum leaks -- edit*

Thats what i thought it was to begin with,bad gas , i threw $10 gas in 2days prior to this happening and then i see the gas station were digging up their tanks, but i have put more gas in since and added dry gas,fuel injector cleaner, didn't help, vacuum leaks i did check and found nothing.Thanks Mark for your help,appreciate it very much ! I thinks it get traded in on a newer dodge truck.

I don't know. I guess if it's driveable just run a couple tanks of good gas through it and see what happens. Keep us posted.

I also drive an '88 Lincoln Mark VII LSC.. When I bought the car it had been sitting in a junk yard for three years. One all-inclusive tune-up got it started, but it had idle trouble.

I know it's a different situation than yours, but my resolution was cleaning up the throttle body then running it up and down the interstate like a bat out of hell for a tank of gas with one can of seafoam. That cleared up my low-rpm stumble.

-Mark T.

just a follow up, my fuel regulator was the culprit and i also have a short somewhere in my check engine light that is why it didnt come on .Mechanic told me it was dumping to much gas in cylinder 2 and 3 causing a random cyl misfire and lots of smoke.Hope this might help somebody else having a similiar problem!

It's good to see you got it all figured out. Thanks for the information.

-Mark T.