okay, so i start the car when its cold in the morning. it cranks pretty long and i have to step on the gas pedal a little to get it to start. once it starts the idle is rough for the first 30 seconds or so.

once i drive it for a minute, the exhaust that comes out is white, when idling theres a nice cloud of white-ness coming out from the back. after 10 minutes, it goes away and the exhaust is normal.
i'm aware of the whole head gasket thing, i checked the coolant level, its normal, its not milky and theres no oil in it. and there's no coolant in the oil, and the exhuast does NOT smell like coolant. once the car is warm, it starts fine. the only thing i can think of that i can check is removing the spark plugs and looking for coolant on top of the piston. but if thats not the case then what else could it be? (i dont think it's oil, it doesnt smell like oil, but i dunno)

if this helps any, the car failed smog horribly in all areas. haha (1993 325is)

A bit of water vapor from the exhaust is normal when you first start up; it's especially noticable on cold mornings. Cold engines get a little bit richer fuel/air mixture to help them run until they reach normal temps, and rich mixtures produce more water vapor in the exhaust. The rough running + failed smog + really noticable water vapor might indicate a failing O2 sensor or leaky injector causing an overly rich mixture.

White smoke when first started is normal. If white smoke continues its possible you have an internal coolant leak, i.e., cracked head/blown head gasket

I sort of doubt that Redondo Beach sees ambient temps low enough to show dense condensation clouds. That would take temps down around or below freezing. Normal condensation and vaporized coolant have entirely different appearances. Once you've seen coolant smoke you'll never mistake it for condensation. If there's any doubt, have the car checked by someone with experience.

The rough idle and white cloud sounds very much like a leaking headgasket that allows coolant to pool in a cylinder when the car sits for a while. Until the coolant is vaporized that cylinder will misfire because the plug is wet.

he's right, it doesnt get too cold here. but i know for a fact that the amount of white smoke coming out is anything but normal and there's something wrong. but the coolant level isnt dropping.

if it is the head gasket how much should it be to get that done and is it bad if i keep driving the car?

I sort of doubt that Redondo Beach sees ambient temps low enough to show dense condensation clouds. That would take temps down around or below freezing. Normal condensation and vaporized coolant have entirely different appearances. Once you've seen coolant smoke you'll never mistake it for condensation. If there's any doubt, have the car checked by someone with experience.

The rough idle and white cloud sounds very much like a leaking headgasket that allows coolant to pool in a cylinder when the car sits for a while. Until the coolant is vaporized that cylinder will misfire because the plug is wet.

well, it is a little rough for 30 seconds, but the exhaust isnt white until about a minute after running, by the the idle has gone to normal. it does not misfire/run rough while it is white. and the thing is, its only for the 1st 5-10 minutes of running. my mechanic informed me that if it was burning coolant it would be doing it all the time. but maybe its just a small build up of coolant?

You'd be surprised how little coolant it takes to produce a very large and very dense white cloud. So it isn't a surprise that you don't see a drop in the coolant level.

And it isn't surprising that you don't see the white cloud as soon as the engine fires. The cylinder containing the coolant won't get hot enough to vaporize the coolant until that coolant has been pumped out into the exhaust and the plug dries out. The coolant in the exhaust won't vaporise until the exhaust gets hot.

A head gasket failure, if that's what it is, always gets worse. And the dangerous part is the possibility of air being pumped into the cooling system and causing an overheat. That can warp or crack the head. I'd guess, if it is only the gasket, that repair would be in the $1600-2000 range (depending on labor rates).

You'd be surprised how little coolant it takes to produce a very large and very dense white cloud. So it isn't a surprise that you don't see a drop in the coolant level.

And it isn't surprising that you don't see the white cloud as soon as the engine fires. The cylinder containing the coolant won't get hot enough to vaporize the coolant until that coolant has been pumped out into the exhaust and the plug dries out. The coolant in the exhaust won't vaporise until the exhaust gets hot.

A head gasket failure, if that's what it is, always gets worse. And the dangerous part is the possibility of air being pumped into the cooling system and causing an overheat. That can warp or crack the head. I'd guess, if it is only the gasket, that repair would be in the $1600-2000 range (depending on labor rates).



hmm, on another thread i heard 700-1000. maybe they were completely wrong though.
my mechanic told me that if it was a head gasket problem, that it wouldnt matter if i kept driving it and that it would cause no harm and just to make sure the coolant level is up there. is this true? or will it cause damage (other then the overheating issue)

i wouldn't rule out a failing water pump.